Star Raiders source code by Lorenz Wiest#
Lorenz Wiest did a tremendous must see job with a complete commented Star Raiders source code at the highest level possible! Highly recommended!!!Every assembly source code should look like this. The reader can take his work as a template on how to do it the right way!
Source Code in TXT-Format#
- StarRaiders.source.txt
; size: 840 KB ; incredible source code listing with assembled hex bytes!!! A must see!!!
- StarRaiders.source.asm.txt ; size: 644 KB ; incredible source code listing without assembled hex bytes, ready to use in an assembler!!! A must see!!!
Read Me from Lorenz Wiest#
Reverse engineered and fully documented STAR RAIDERS source codeSTAR RAIDERS is a seminal computer game, published by Atari Inc. in 1979 as one of the first titles for the original Atari 8-bit Home Computer System (Atari 400 and 800).
During the last years, as a hobby afterhours project, I reverse engineered a complete, extensively documented assembly language source code of STAR RAIDERS. I reverse engineered the source code directly from the binary file of the ROM cartridge, finishing it in September 2015.
This repo contains both the reverse enginered assembly source code input StarRaiders.source.asm.txt
and output StarRaiders.source.txt.You may find this useful if you are curious about the internals of STAR RAIDERS or if you are planning to make your own, modified version.
After very positive reader feedback on the initial release of my reverse engineered source code I reviewed it again, resulting in a minor update.
Enjoy -- Lorenz
P.S. I was absolutely thrilled to learn that in October 2015 scans of the original STAR RAIDERS source code
re-surfaced.To my delight, inspection of the original source code confirmed the findings of my reverse engineered version and caused only a few trivial corrections.
Even more, the documentation of my reverse engineered version adds a substantial amount of information - from overall theory of operation down to some tricky details - to the understanding of the often sparsely commented original (quite expected for source code never meant for publication). So, if you are interested in learning how STAR RAIDERS works, my reverse engineered source code could be of help to you.
Extras#
Genome Sequence#
The picture below shows the 'genome sequence' of the reverse engineered STAR RAIDERS 8 KB ROM (which I prepared for a publication. I stacked the 8192 bytes vertically, with each byte represented by a tiny, solid horizontal line of 8 pixels. Then, I split the stack into strips of 192 bytes, arranged side-by-side. The segments of the stack are color-coded:- Code (main game loop and subroutines) is in alternating shades of blue.
- Data (lookup tables, texts, etc.) is in alternating shades of green.
- Bitmap data (Player-Missile shapes and character set) is in alternating shades of purple and the solid line of a byte is replaced by its actual bit pattern.
 |
STAR RAIDERS 8KB ROM Genome Sequence ; thank you so much Lorenz, that is totally incredible! :-)
ColorSheets#
- STAR RAIDERS Color Sheets ; size: 250 KB
DisplayListSheets#
- STAR RAIDERS Display List Sheets ; size: 250 KB
References#
- Original post of the source code
- AtariAge Forum - Fully documented, reverse-engineered STAR RAIDERS source code available
- Link at github of the source code
- Wikipedia 'Star Raiders'
- ANTIC The Atari 8-bit Podcast
- Star Raiders Tribute Page
- Brainwagon - Deconstructing the Classic Atari Game: Star Raiders
- Article 'Reverse Engineering Star Raiders', PoC GTFO 0x13, p. 5-20, October 2016
Source Code Listing#
00001 ;*******************************************************************************
00002 ;* *
00003 ;* S T A R R A I D E R S *
00004 ;* *
00005 ;* for the Atari 8-bit Home Computer System *
00006 ;* *
00007 ;* Reverse engineered and documented assembly language source code *
00008 ;* *
00009 ;* by *
00010 ;* *
00011 ;* Lorenz Wiest *
00012 ;* *
00013 ;* (lo.wiest(at)web.de) *
00014 ;* *
00015 ;* First Release *
00016 ;* 22-SEP-2015 *
00017 ;* *
00018 ;* Last Update *
00019 ;* 10-DEC-2016 *
00020 ;* *
00021 ;* STAR RAIDERS was created by Douglas Neubauer *
00022 ;* STAR RAIDERS was published by Atari Inc. *
00023 ;* *
00024 ;*******************************************************************************
00025
00026 ; I wrote this document out of my own curiosity. When STAR RAIDERS was released
00027 ; in 1979 it became the killer app for the Atari 8-bit Home Computer System.
00028 ; Since then I have always been wondering what made it tick and how its (at that
00029 ; time) spectacular 3D graphics worked, especially the rotating star field.
00030 ; Impressed by "The Atari BASIC Source Book" I decided to reverse engineer the
00031 ; STAR RAIDERS 8KB ROM cartridge to recreate a fully documented assembly
00032 ; language source code file. I had no access to the original source code, so the
00033 ; only way to succeed was a combination of educated guesses, trial-and-error,
00034 ; and patience. Eventually, I made it.
00035 ;
00036 ; Essential in preparing this document were three programs I wrote:
00037 ;
00038 ; (1) A 6502-cross-assembler based on the syntax of the MAC/65 assembler for the
00039 ; Atari 8-bit Home Computer System to create the binary file that I verified
00040 ; against the binary of the original ROM cartridge.
00041 ;
00042 ; (2) A text formatter to layout the source code file with its copious comment
00043 ; sections. This was a big time saver, because as the documentation grew the
00044 ; source code had to be reformatted over and over again.
00045 ;
00046 ; (3) A symbol checker to verify that the ubiquitous symbol-value pairs in the
00047 ; documentation match the corresponding symbol values produced by the
00048 ; assembler.
00049 ;
00050 ; This assembly language source code file is compatible with the MAC/65
00051 ; assembler for the Atari 8-bit Home Computer System. I was able to assemble it
00052 ; on an emulated Atari running MAC/65, producing the identical binary of the ROM
00053 ; cartridge.
00054 ;
00055 ; Your feedback is welcome! Send feedback to lo.wiest(at)web.de.
00056 ;
00057 ; Enjoy! -- Lorenz
00058
00059 ;*******************************************************************************
00060 ;* *
00061 ;* N O T A T I O N *
00062 ;* *
00063 ;*******************************************************************************
00064
00065 ; BITS AND BYTES
00066 ;
00067 ; o A "byte" consists of 8 bits. They are numbered B7..0. Bit B0 is the least
00068 ; significant bit.
00069 ;
00070 ; o A "word" consists of 16 bits. They are numbered B15..B0. Bit B0 is the
00071 ; least significant bit. A word is stored in low-order then high-order byte
00072 ; order.
00073 ;
00074 ; o The high-order byte ("high byte") of a word consists of bits B15..8 of the
00075 ; word.
00076 ;
00077 ; o The low-order byte ("low byte") of a word consists of bits B7..0 of the
00078 ; word.
00079 ;
00080 ; NUMBERS
00081 ;
00082 ; o The dollar sign ($) prefixes hexadecimal numbers.
00083 ; Example: $101 is the decimal number 257.
00084 ;
00085 ; o The percent sign (%) prefixes binary numbers.
00086 ; Example: %101 is the decimal number 5.
00087 ;
00088 ; o The asterisk (*) is a wildcard character for a single hexadecimal or
00089 ; binary digit.
00090 ; Example: $0*00 is a placeholder for the numbers $0000, $0100, ..., $0F00.
00091 ;
00092 ; o The lowercase R (r) is a wildcard character for a single random
00093 ; hexadecimal or binary digit. The random digit r is chosen by a random
00094 ; number generator.
00095 ; Example: %00r0 is a placeholder for the numbers %0000 or %0010.
00096 ;
00097 ; OPERATORS
00098 ;
00099 ; o The exclamation mark (!) is the binary OR operator.
00100 ; Example: $01!$02 is $03.
00101 ;
00102 ; o The less-than sign (<) indicates bits B7..0 of a word.
00103 ; Example: <$1234 is $34.
00104 ;
00105 ; o The greater-than sign (>) indicates bits B15..8 of a word.
00106 ; Example: >$1234 is $12.
00107 ;
00108 ; o A pair of brackets ([]) groups mathematical expressions.
00109 ; Example: [3-1]*4 is 8.
00110 ;
00111 ; ASSEMBLY LANGUAGE
00112 ;
00113 ; o The uppercase A (A) indicates the accumulator register of the 6502 CPU.
00114 ;
00115 ; o The uppercase X (X) indicates the X register of the 6502 CPU.
00116 ;
00117 ; o The uppercase Y (Y) indicates the Y register of the 6502 CPU.
00118 ;
00119 ; o The prefix uppercase L and dot (L.) indicates a local variable, a memory
00120 ; location used temporarily in a subroutine.
00121 ;
00122 ; PSEUDO-FUNCTIONS
00123 ;
00124 ; o The function ABS(<num>) returns the absolute value of <num>.
00125 ; Example: ABS(3) returns 3.
00126 ; Example: ABS(-3) returns 3.
00127 ;
00128 ; o The function RND(<num1>..<num2>) returns a random integer in
00129 ; <num1>..<num2>.
00130 ; Example: RND(3..5) returns a random number out of 3, 4, or 5.
00131 ;
00132 ; o The function MAX(<num1>,<num2>) returns the larger number of <num1> and
00133 ; <num2>.
00134 ; Example: MAX(2,4) returns 4.
00135 ;
00136 ; VECTORS
00137 ;
00138 ; o The lowercase X (x) indicates the x-axis of the 3D coordinate system.
00139 ;
00140 ; o The lowercase Y (y) indicates the y-axis of the 3D coordinate system.
00141 ;
00142 ; o The lowercase Z (z) indicates the z-axis of the 3D coordinate system.
00143 ;
00144 ; o Components of a position vector (called "coordinates") have the arbitrary
00145 ; unit <KM> ("kilometers").
00146 ;
00147 ; o Components of a velocity vector have the arbitrary unit <KM/H>
00148 ; ("kilometers per hour").
00149 ;
00150 ; o A positive component of a position vector (coordinate) in hexadecimal
00151 ; notation is written in the form +$<hexNum> <KM>. <hexNum> is an unsigned
00152 ; integer value.
00153 ; Example: The starbase is +$1000 (or 4096) <KM> ahead of our starship.
00154 ;
00155 ; o A negative component of a position vector (coordinate) in hexadecimal
00156 ; notation is written in the form -($<hexNum>) <KM>. <hexNum> is an unsigned
00157 ; integer value. To calculate the actual bit pattern of this coordinate
00158 ; value compute the two's-complement of <hexNum>. See also "ON POSITION
00159 ; VECTORS".
00160 ; Example: The starbase is -($1000) (or -4096) <KM> behind our starship.
00161 ;
00162 ; o An absolute component of a position vector (coordinate) in hexadecimal
00163 ; notation is written in the form $<hexNum> <KM>. <hexNum> is an unsigned
00164 ; integer value.
00165 ; Example: The Zylon fighter fires when it is closer than $1000 (or 4096)
00166 ; <KM>.
00167 ;
00168 ; DISPLAY LIST
00169 ;
00170 ; o The following notation is used for Display List instructions:
00171 ;
00172 ; BLK<n> = Display <n> blank video lines (<n> in 1..8)
00173 ; GR1 = Display one GRAPHICS 1 row of 20 text characters
00174 ; GR2 = Display one GRAPHICS 2 row of 20 text characters
00175 ; GR7 = Display one GRAPHICS 7 row of 160 pixels
00176 ; DLI = Trigger a Display List Interrupt
00177 ; ... @ <addr> = Point to screen memory at address <addr>
00178 ; JMP @ <addr> = Jump to next Display List instruction at address <addr>
00179 ; WAITJMP @ <addr> = Wait for vertical blank phase, then jump to next
00180 ; Display List instruction at address <addr>
00181 ;
00182 ; MISCELLANEOUS
00183 ;
00184 ; o Probabilities are written in the form <percentage>% (<number of values out
00185 ; of the possible values>:<number of possible values>).
00186 ; Example: The probability to throw the number 3 with a die is 16% (1:6).
00187 ;
00188 ; o A "game loop iteration" (or "game loop") is a single execution of the game
00189 ; loop, the main program of the game.
00190 ;
00191 ; o A "TICK" is the time span it takes to update the TV screen (1/60 s on an
00192 ; NTSC TV system, 1/50 s on a PAL TV system).
00193 ;
00194 ; o A pair of braces ({}) encloses color names.
00195 ; Example: {BLACK}
00196 ;
00197 ; o A pair of parentheses enclosing a question mark ((?)) indicates code that
00198 ; is not well understood.
00199 ;
00200 ; o A pair of parentheses enclosing an exclamation mark ((!)) indicates a
00201 ; potential bug.
00202
00203 ;*******************************************************************************
00204 ;* *
00205 ;* O V E R V I E W *
00206 ;* *
00207 ;*******************************************************************************
00208
00209 ; ON POSITION VECTORS
00210 ;
00211 ; The game uses a 3D coordinate system with the position of our starship at the
00212 ; center of the coordinate system and the following coordinate axes:
00213 ;
00214 ; o The x-axis points to the right.
00215 ; o The y-axis points up.
00216 ; o The z-axis points in flight direction.
00217 ;
00218 ; By the way, this is called a "left-handed" coordinate system.
00219 ;
00220 ; The locations of all space objects (Zylon ships, meteors, photon torpedoes,
00221 ; starbase, transfer vessel, Hyperwarp Target Marker, stars, and explosion
00222 ; fragments) are described by a "position vector".
00223 ;
00224 ; A "position vector" is composed of an x, y, and z component. The values of the
00225 ; position vector components are called the x, y, and z "coordinates". They have
00226 ; the arbitrary unit <KM>.
00227 ;
00228 ; Each coordinate is a signed 17-bit integer number, which fits into 3 bytes:
00229 ;
00230 ; Sign Mantissa
00231 ; B16 B15...B8 B7....B0
00232 ; | | | | |
00233 ; 0000000* ******** ********
00234 ;
00235 ; o B16 contains the sign bit. Used values are:
00236 ; 1 -> Positive sign
00237 ; 0 -> Negative sign
00238 ; o B15..0 contain the coordinate value (or "mantissa") as a two's-complement
00239 ; integer number.
00240 ;
00241 ; The range of a position vector component is -65536..+65535 <KM>.
00242 ;
00243 ; Examples:
00244 ;
00245 ; 00000001 11111111 11111111 = +65535 <KM>
00246 ; 00000001 00010000 00000000 = +4096 <KM>
00247 ; 00000001 00001111 11111111 = +4095 <KM>
00248 ; 00000001 00000001 00000000 = +256 <KM>
00249 ; 00000001 00000000 11111111 = +255 <KM>
00250 ; 00000001 00000000 00010000 = +16 <KM>
00251 ; 00000001 00000000 00001111 = +15 <KM>
00252 ; 00000001 00000000 00000001 = +1 <KM>
00253 ; 00000001 00000000 00000000 = +0 <KM>
00254 ;
00255 ; 00000000 11111111 11111111 = -1 <KM>
00256 ; 00000000 11111111 11111110 = -2 <KM>
00257 ; 00000000 11111111 11110001 = -15 <KM>
00258 ; 00000000 11111111 11110000 = -16 <KM>
00259 ; 00000000 11111111 00000001 = -255 <KM>
00260 ; 00000000 11111111 00000000 = -256 <KM>
00261 ; 00000000 11110000 00000001 = -4095 <KM>
00262 ; 00000000 11110000 00000000 = -4096 <KM>
00263 ; 00000000 00000000 00000000 = -65536 <KM>
00264 ;
00265 ; The position vector for each space object is stored in 9 tables:
00266 ;
00267 ; o XPOSSIGN ($09DE..$0A0E), XPOSHI ($0A71..$0AA1), and XPOSLO ($0B04..$0B34)
00268 ; o YPOSSIGN ($0A0F..$0A3F), YPOSHI ($0AA2..$0AD2), and YPOSLO ($0B35..$0B65)
00269 ; o ZPOSSIGN ($09AD..$09DD), ZPOSHI ($0A40..$0A70), and ZPOSLO ($0AD3..$0B03)
00270 ;
00271 ; There are up to 49 space objects used in the game simultaneously, thus each
00272 ; table is 49 bytes long.
00273 ;
00274 ; o Position vectors 0..4 belong to space objects represented by PLAYERs
00275 ; (Zylon ships, meteors, photon torpedoes, starbase, transfer vessel, and
00276 ; Hyperwarp Target Marker).
00277 ; o Position vectors 5..48 belong to space objects represented by PLAYFIELD
00278 ; pixels. Position vectors 5..16 (stars, explosion fragments) are used for
00279 ; stars, position vectors 17..48 are used for explosion fragments and star
00280 ; trails.
00281 ;
00282 ; INFO: The x and y coordinates of space objects are converted and displayed by
00283 ; the THETA and PHI readouts of the Control Panel Display in "gradons". The
00284 ; z-coordinate is converted and displayed by the RANGE readout in "centrons".
00285 ; The conversion takes place in subroutine SHOWDIGITS ($B8CD) where the high
00286 ; byte of a coordinate (with values $00..$FF) is transformed with lookup table
00287 ; MAPTOBCD99 ($0EE9) into a BCD value of 00..99 in "gradons" or "centrons".
00288 ;
00289 ;
00290 ; ON VELOCITY VECTORS
00291 ;
00292 ; The velocities of all space objects are described by a "velocity vector". The
00293 ; velocity vector is relative to our starship.
00294 ;
00295 ; A "velocity vector" is composed of an x, y, and z component. The values of the
00296 ; velocity vector components are called the x, y, and z "velocities". They have
00297 ; the arbitrary unit <KM/H>.
00298 ;
00299 ; Each velocity vector component is an 8-bit integer number, which fits into 1
00300 ; byte:
00301 ;
00302 ; B7 Sign
00303 ; |
00304 ; |B6...B0 Mantissa
00305 ; || |
00306 ; ********
00307 ;
00308 ; o B7 contains the sign bit. Used values are:
00309 ; 0 -> Positive sign, movement along the positive coordinate axis
00310 ; (x-velocity: right, y-velocity: up, z-velocity: in flight direction)
00311 ; 1 -> Negative sign, movement along the negative coordinate axis
00312 ; (x-velocity: left, y-velocity: down, z-velocity: in reverse flight
00313 ; direction)
00314 ; o B6..B0 contain the velocity value (or "mantissa"). It is an unsigned
00315 ; number.
00316 ;
00317 ; The range of a velocity vector component is -127..+127 <KM/H>.
00318 ;
00319 ; Examples:
00320 ;
00321 ; 01111111 = +127 <KM/H>
00322 ; 00010000 = +16 <KM/H>
00323 ; 00001111 = +15 <KM/H>
00324 ; 00000001 = +1 <KM/H>
00325 ; 00000000 = +0 <KM/H>
00326 ;
00327 ; 10000000 = -0 <KM/H>
00328 ; 10000001 = -1 <KM/H>
00329 ; 10001111 = +15 <KM/H>
00330 ; 10010000 = +16 <KM/H>
00331 ; 11111111 = -127 <KM/H>
00332 ;
00333 ; The velocity vector for each space object stored in 3 tables:
00334 ;
00335 ; o XVEL ($0B97..$0BC7)
00336 ; o YVEL ($0BC8..$0BF8)
00337 ; o ZVEL ($0B66..$0B96)
00338 ;
00339 ; There are up to 49 space objects used in the game simultaneously, thus each
00340 ; table is 49 bytes long.
00341 ;
00342 ; o Velocity vectors 0..4 belong to space objects represented by PLAYERs
00343 ; (Zylon ships, meteors, photon torpedoes, starbase, transfer vessel, and
00344 ; Hyperwarp Target Marker).
00345 ; o Velocity vectors 5..48 belong to space objects represented by PLAYFIELD
00346 ; pixels. Velocity vectors 5..16 are used for stars, velocity vectors 17..48
00347 ; are used for explosion fragments and star trails.
00348 ;
00349 ; INFO: The velocity of our starship is converted and displayed by the VELOCITY
00350 ; readout of the Control Panel Display in "metrons per second" units. The
00351 ; conversion takes place in subroutine SHOWDIGITS ($B8CD) where our starship's
00352 ; velocity VELOCITYL ($70) (with values $00..$FF) is transformed with lookup
00353 ; table MAPTOBCD99 ($0EE9) into a BCD value of 00..99 in "metrons per second".
00354
00355 ;*******************************************************************************
00356 ;* *
00357 ;* M E M O R Y M A P *
00358 ;* *
00359 ;*******************************************************************************
00360 ;
00361 ; The following variables are not changed by a SYSTEM RESET:
00362 ;
00363 ; $62 MISSIONLEVEL
00364 ;
00365 ; Mission level. Used values are:
00366 ; $00 -> NOVICE mission
00367 ; $01 -> PILOT mission
00368 ; $02 -> WARRIOR mission
00369 ; $03 -> COMMANDER mission
00370 ;
00371 ; $63 FKEYCODE
00372 ;
00373 ; Function key code. Used values are:
00374 ; $00 -> No function key pressed
00375 ; $01 -> START function key pressed
00376 ; $02 -> SELECT function key pressed
00377 ;
00378 ; $64 ISDEMOMODE
00379 ;
00380 ; Indicates whether the game is in game or in demo mode. Used values
00381 ; are:
00382 ; $00 -> Game mode
00383 ; $FF -> Demo mode
00384 ;
00385 ; $65 NEWTITLEPHR
00386 ;
00387 ; New title phrase offset for the text in the title line. The new title
00388 ; phrase is not immediately displayed in the title line but only after
00389 ; the display time of the currently displayed title phrase has expired.
00390 ; Thus, setting a value to NEWTITLEPHR ($65) "enqueues" the display of
00391 ; new title phrase. Used values are:
00392 ; $00..$7B -> Title phrase offset into PHRASETAB ($BBAA)
00393 ; $FF -> Hide title line
00394 ;
00395 ; See also TITLEPHR ($D1).
00396 ;
00397 ; $66 IDLECNTHI
00398 ;
00399 ; Idle counter (high byte). Forms a 16-bit counter together with
00400 ; IDLECNTLO ($77), which is incremented during the execution of the
00401 ; Vertical Blank Interrupt handler VBIHNDLR ($A6D1). IDLECNTHI ($66) is
00402 ; reset to 0 when the joystick trigger or a keyboard key has been
00403 ; pressed, or to 1..3 when a function key has been pressed. When
00404 ; IDLECNTHI ($66) reaches a value of 128 (after about 10 min idle time)
00405 ; the game enters demo mode.
00406 ;
00407 ; The following variables are set to 0 after a SYSTEM RESET:
00408 ;
00409 ; $67 ISVBISYNC
00410 ;
00411 ; Indicates whether the Vertical Blank Interrupt handler VBIHNDLR
00412 ; ($A6D1) is executed. Used to synchronize the execution of a new game
00413 ; loop iteration in GAMELOOP ($A1F3) with the vertical blank phase.
00414 ; Used values are:
00415 ; $00 -> Halt execution at start of game loop and wait for VBI
00416 ; $FF -> Continue execution of game loop
00417 ;
00418 ; $68..$69 MEMPTR
00419 ;
00420 ; A 16-bit memory pointer.
00421 ;
00422 ; Also used as a local variable.
00423 ;
00424 ; $6A..$6B DIVIDEND
00425 ;
00426 ; A 16-bit dividend value passed in GAMELOOP ($A1F3) to subroutine
00427 ; PROJECTION ($AA21) to calculate a division.
00428 ;
00429 ; Also used as a local variable.
00430 ;
00431 ; $6C Used as a local variable.
00432 ;
00433 ; $6D JOYSTICKDELTA
00434 ;
00435 ; Used to pass joystick directions from GAMELOOP ($A1F3) to subroutine
00436 ; ROTATE ($B69B). Used values are:
00437 ; $01 -> Joystick pressed right or up
00438 ; $00 -> Joystick centered
00439 ; $FF -> Joystick pressed left or down
00440 ;
00441 ; Also used as a local variable.
00442 ;
00443 ; $6E Used as a local variable.
00444 ;
00445 ; $70 VELOCITYLO
00446 ;
00447 ; Our starship's current velocity (low byte) in <KM/H>. Forms a 16-bit
00448 ; value together with VELOCITYHI ($C1). In subroutine UPDPANEL ($B804),
00449 ; VELOCITYLO ($70) is mapped to a BCD-value in 00..99 and displayed by
00450 ; the VELOCITY readout of the Control Panel Display. See also
00451 ; NEWVELOCITY ($71).
00452 ;
00453 ; $71 NEWVELOCITY
00454 ;
00455 ; Our starship's new velocity (low byte) in <KM/H>. It is set by
00456 ; pressing one of the speed keys '0'..'9'. A pressed speed key is
00457 ; mapped to the new velocity value with VELOCITYTAB ($BAB4).
00458 ;
00459 ; $72 COUNT8
00460 ;
00461 ; Wrap-around counter. Counts from 0..7, then starts over at 0. It is
00462 ; incremented every game loop iteration. It is used to change the
00463 ; brightness of stars and explosion fragments more randomly in GAMELOOP
00464 ; ($A1F3) and to slow down the movement of the hyperwarp markers of the
00465 ; Galactic Chart in subroutine SELECTWARP ($B162).
00466 ;
00467 ; $73 EXPLLIFE
00468 ;
00469 ; Explosion lifetime. It is decremented every game loop iteration. Used
00470 ; values are:
00471 ; $00 -> Explosion is over
00472 ; < $18 -> Number of explosion fragment space objects is decremented
00473 ; < $70 -> HITBADNESS ($8A) is reset
00474 ; $80 -> Initial value at start of explosion
00475 ;
00476 ; $74 CLOCKTIM
00477 ;
00478 ; Star date clock delay timer. Counts down from 40 to 0. It is
00479 ; decremented every game loop iteration. When the timer falls below 0
00480 ; the last digit of the star date of the Galactic Chart Panel Display
00481 ; is increased and the timer is reset to a value of 40.
00482 ;
00483 ; $75 DOCKSTATE
00484 ;
00485 ; State of docking operation. Used values are:
00486 ; $00 -> NOT DOCKED
00487 ; $01 -> TRANSFER COMPLETE
00488 ; $81 -> RETURN TRANSFER VESSEL
00489 ; $FF -> ORBIT ESTABLISHED
00490 ;
00491 ; $76 COUNT256
00492 ;
00493 ; Wrap-around counter. Counts from 0..255, then starts over at 0. It is
00494 ; incremented every game loop iteration. It is used to make the
00495 ; starbase pulsate in brightness in GAMELOOP ($A1F3) and to decide on
00496 ; the creation of a meteor in subroutine MANEUVER ($AA79).
00497 ;
00498 ; $77 IDLECNTLO
00499 ;
00500 ; Idle counter (low byte). Forms a 16-bit counter together with
00501 ; IDLECNTHI ($66), which is incremented during the execution of the
00502 ; Vertical Blank Interrupt handler VBIHNDLR ($A6D1).
00503 ;
00504 ; NOTE: This variable is never properly initialized except at initial
00505 ; cartridge startup (cold start).
00506 ;
00507 ; $78 ZYLONUNITTIM
00508 ;
00509 ; Zylon unit movement timer. This delay timer triggers movement of
00510 ; Zylon units on the Galactic Chart. At the start of the game, the
00511 ; timer is initialized to a value of 100. It is decremented every 40
00512 ; game loop iterations. When the timer falls below 0 the Zylon units
00513 ; move on the Galactic Chart and the timer value is reset to 49. If a
00514 ; starbase is surrounded the timer is reset to 99 to buy you some extra
00515 ; time to destroy one of the surrounding Zylon units.
00516 ;
00517 ; $79 MAXSPCOBJIND
00518 ;
00519 ; Maximum index of used space objects in the current game loop
00520 ; iteration. Frequently used values are:
00521 ; $10 -> During regular cruise (5 PLAYER space objects + 12 PLAYFIELD
00522 ; space objects (stars), counted $00..$10)
00523 ; $30 -> During explosion or hyperwarp (5 PLAYER space objects + 12
00524 ; PLAYFIELD space objects (stars) + 32 PLAYFIELD space objects
00525 ; (explosion fragments or stars of star trails), counted
00526 ; $00..$30)
00527 ;
00528 ; $7A OLDMAXSPCOBJIND
00529 ;
00530 ; Maximum index of used space objects in the previous game loop
00531 ; iteration. Frequently used values are:
00532 ; $10 -> During regular cruise (5 PLAYER space objects + 12 PLAYFIELD
00533 ; space objects (stars), counted $00..$10)
00534 ; $30 -> During explosion or hyperwarp (5 PLAYER space objects + 12
00535 ; PLAYFIELD space objects (stars) + 32 PLAYFIELD space objects
00536 ; (explosion fragments or stars of star trails), counted
00537 ; $00..$30)
00538 ;
00539 ; $7B ISSTARBASESECT
00540 ;
00541 ; Indicates whether a starbase is in this sector. Used values are:
00542 ; $00 -> Sector contains no starbase
00543 ; $FF -> Sector contains starbase
00544 ;
00545 ; $7C ISTRACKCOMPON
00546 ;
00547 ; Indicates whether the Tracking Computer is on or off. Used values
00548 ; are:
00549 ; $00 -> Tracking Computer is off
00550 ; $FF -> Tracking Computer is on
00551 ;
00552 ; $7D DRAINSHIELDS
00553 ;
00554 ; Energy drain rate of the Shields per game loop iteration in energy
00555 ; subunits. See also subroutine UPDPANEL ($B804). Used values are:
00556 ; $00 -> Shields are off
00557 ; $08 -> Shields are on
00558 ;
00559 ; $7E DRAINATTCOMP
00560 ;
00561 ; Energy drain rate of the Attack Computer per game loop iteration in
00562 ; energy subunits. See also subroutine UPDPANEL ($B804). Used values
00563 ; are:
00564 ; $00 -> Attack Computer off
00565 ; $02 -> Attack Computer on
00566 ;
00567 ; $7F ENERGYCNT
00568 ;
00569 ; Running counter of consumed energy subunits (256 energy subunits = 1
00570 ; energy unit displayed by the 4-digit ENERGY readout of the Control
00571 ; Panel Display). Forms an invisible fractional or "decimals" part of
00572 ; the 4-digit ENERGY readout of the Control Panel Display. See also
00573 ; subroutine UPDPANEL ($B804).
00574 ;
00575 ; $80 DRAINENGINES
00576 ;
00577 ; Energy drain rate of our starship's Engines per game loop iteration
00578 ; in energy subunits (256 energy subunits = 1 energy unit displayed by
00579 ; the 4-digit ENERGY readout of the Control Panel Display). Values are
00580 ; picked from table DRAINRATETAB ($BAD3). See also subroutine UPDPANEL
00581 ; ($B804).
00582 ;
00583 ; $81 SHIELDSCOLOR
00584 ;
00585 ; Shields color. Used values are:
00586 ; $00 -> {BLACK} (Shields are off)
00587 ; $A0 -> {DARK GREEN} (Shields are on)
00588 ;
00589 ; $82 PL3HIT
00590 ;
00591 ; Collision register of PLAYER3 (usually our starship's photon torpedo
00592 ; 0) with other PLAYERs. Used values are:
00593 ; $00 -> No collision
00594 ; > $00 -> PLAYER3 has collided with another PLAYER space object. See
00595 ; subroutine COLLISION ($AF3D) for details which PLAYER has
00596 ; been hit by PLAYER3.
00597 ;
00598 ; $83 PL4HIT
00599 ;
00600 ; Collision register of PLAYER4 (usually our starship's photon torpedo
00601 ; 1) with other PLAYERs. Used values are:
00602 ; $00 -> No collision
00603 ; > $00 -> PLAYER4 has collided with another PLAYER space object. See
00604 ; subroutine COLLISION ($AF3D) for details which PLAYER has
00605 ; been hit by PLAYER4.
00606 ;
00607 ; $84 OLDTRIG0
00608 ;
00609 ; Joystick trigger state. Used values are:
00610 ; $00 -> Joystick trigger was pressed
00611 ; $01 -> Joystick trigger was not pressed
00612 ; $AA -> Joystick trigger was "virtually" pressed (will launch
00613 ; another of our starship's photon torpedoes, see subroutine
00614 ; TRIGGER ($AE29).
00615 ;
00616 ; $86 ISTRACKING
00617 ;
00618 ; Indicates whether one of our starship's photon torpedoes is currently
00619 ; tracking (homing in on) the target space object. Used values are:
00620 ; $00 -> No target space object tracked. Our starship's photon
00621 ; torpedoes will fly just straight ahead.
00622 ; > $00 -> Tracking a target space object. Our starship's photon
00623 ; torpedoes will home in on the tracked space object.
00624 ;
00625 ; $87 BARRELNR
00626 ;
00627 ; Barrel from which our starship's next photon torpedo will be
00628 ; launched. Used values are:
00629 ; $00 -> Left barrel
00630 ; $01 -> Right barrel
00631 ;
00632 ; $88 LOCKONLIFE
00633 ;
00634 ; Lifetime of target lock-on. A target remains in lock-on while
00635 ; LOCKONLIFE ($88) counts down from 12 to 0. It is decremented every
00636 ; game loop iteration.
00637 ;
00638 ; $89 PLTRACKED
00639 ;
00640 ; Index of currently tracked PLAYER. It is copied in subroutine TRIGGER
00641 ; ($AE29) from TRACKDIGIT ($095C). Used values are:
00642 ; $00 -> Track Zylon ship 0
00643 ; $01 -> Track Zylon ship 1
00644 ; $02 -> Track starbase during docking operations
00645 ; $03 -> Track Hyperwarp Target Marker during hyperwarp
00646 ;
00647 ; $8A HITBADNESS
00648 ;
00649 ; Severity of a Zylon photon torpedo hit. Used values are:
00650 ; $00 -> NO HIT
00651 ; $7F -> SHIELDS HIT
00652 ; $FF -> STARSHIP DESTROYED
00653 ;
00654 ; $8B REDALERTLIFE
00655 ;
00656 ; Lifetime of red alert. It decreases from 255 to 0. It is decremented
00657 ; every game loop iteration.
00658 ;
00659 ; $8C WARPDEPRROW
00660 ;
00661 ; Departure hyperwarp marker row number on the Galactic Chart. It is
00662 ; given in Player/Missile pixels relative to the top Galactic Chart
00663 ; border. It is initialized to a value of $47 (vertical center of
00664 ; Galactic Chart). Divide this value by 16 to get the departure sector
00665 ; row number. Used values are: $00..$7F.
00666 ;
00667 ; $8D WARPDEPRCOLUMN
00668 ;
00669 ; Departure hyperwarp marker column number on the Galactic Chart. It is
00670 ; given in Player/Missile pixels relative to the left Galactic Chart
00671 ; border and initialized to a value of $43 (horizontal center of
00672 ; Galactic Chart). Divide this value by 8 to get the departure sector
00673 ; column number. Used values are: $00..$7F.
00674 ;
00675 ; $8E WARPARRVROW
00676 ;
00677 ; Arrival hyperwarp marker row number on the Galactic Chart in
00678 ; Player/Missile pixels relative to top Galactic Chart border. It is
00679 ; initialized to a value of $47 (vertical center of Galactic Chart).
00680 ; Divide this value by 16 to get the arrival sector row number. Used
00681 ; values are: $00..$7F.
00682 ;
00683 ; $8F WARPARRVCOLUMN
00684 ;
00685 ; Arrival hyperwarp marker column number on the Galactic Chart in
00686 ; Player/Missile pixels relative to left Galactic Chart border. It is
00687 ; initialized to a value of $43 (horizontal center of Galactic Chart).
00688 ; Divide this value by 8 to get the arrival sector column number. Used
00689 ; values are: $00..$7F.
00690 ;
00691 ; $90 CURRSECTOR
00692 ;
00693 ; Galactic Chart sector of the current location of our starship. At the
00694 ; start of the game it is initialized to a value of $48. Used values
00695 ; are: $00..$7F with, for example,
00696 ; $00 -> NORTHWEST corner sector
00697 ; $0F -> NORTHEAST corner sector
00698 ; $70 -> SOUTHWEST corner sector
00699 ; $7F -> SOUTHWEST corner sector
00700 ;
00701 ; See also ARRVSECTOR ($92).
00702 ;
00703 ; $91 WARPENERGY
00704 ;
00705 ; Energy required to hyperwarp between the departure and arrival
00706 ; hyperwarp marker locations on the Galactic Chart divided by 10.
00707 ; Values are picked from table WARPENERGYTAB ($BADD). Multiply this
00708 ; value by 10 to get the actual value in energy units displayed by the
00709 ; Galactic Chart Panel Display.
00710 ;
00711 ; $92 ARRVSECTOR
00712 ;
00713 ; Galactic Chart arrival sector of our starship after hyperwarp. Used
00714 ; values are: $00..$7F with, for example,
00715 ; $00 -> NORTHWEST corner sector
00716 ; $0F -> NORTHEAST corner sector
00717 ; $70 -> SOUTHWEST corner sector
00718 ; $7F -> SOUTHWEST corner sector
00719 ;
00720 ; See also CURRSECTOR ($90).
00721 ;
00722 ; $93 HUNTSECTOR
00723 ;
00724 ; Galactic Chart sector of the starbase toward which the Zylon units
00725 ; are currently moving. Used values are: $00..$7F with, for example,
00726 ; $00 -> NORTHWEST corner sector
00727 ; $0F -> NORTHEAST corner sector
00728 ; $70 -> SOUTHWEST corner sector
00729 ; $7F -> SOUTHWEST corner sector
00730 ;
00731 ; $94 HUNTSECTCOLUMN
00732 ;
00733 ; Galactic Chart sector column number of the starbase toward which the
00734 ; Zylon units are currently moving. Used values are: 0..15.
00735 ;
00736 ; $95 HUNTSECTROW
00737 ;
00738 ; Galactic Chart sector row number of the starbase toward which the
00739 ; Zylon units are currently moving. Used values are: 0..7.
00740 ;
00741 ; $96..$9E NEWZYLONDIST
00742 ;
00743 ; Table of distances between a Zylon unit and the hunted starbase when
00744 ; the Zylon unit is tentatively moved in one of the 9 possible
00745 ; directions NORTH, NORTHWEST, WEST, SOUTHWEST, SOUTH, SOUTHEAST, EAST,
00746 ; NORTHEAST, CENTER. Used to decide into which sector the Zylon unit
00747 ; should move.
00748 ;
00749 ; $9E OLDZYLONDIST
00750 ;
00751 ; Current distance between the Zylon unit and the hunted starbase.
00752 ;
00753 ; $9F HUNTTIM
00754 ;
00755 ; Delay timer for Zylon units to decide on which starbase to hunt. It
00756 ; counts down from 7. It is decremented every game loop iteration. When
00757 ; the timer falls below 0 the Zylon units re-decide toward which
00758 ; starbase to move.
00759 ;
00760 ; $A0 BLIPCOLUMN
00761 ;
00762 ; Top-left screen pixel column number of blip shape displayed in the
00763 ; Attack Computer Display. Used in subroutine UPDATTCOMP ($A7BF). Used
00764 ; values are: 120..142.
00765 ;
00766 ; $A1 BLIPROW
00767 ;
00768 ; Top-left screen pixel row number of blip shape displayed in the
00769 ; Attack Computer Display. Used in subroutine UPDATTCOMP ($A7BF). Used
00770 ; values are: 71..81.
00771 ;
00772 ; $A2 BLIPCYCLECNT
00773 ;
00774 ; Blip cycle counter. It controls drawing the blip shape in the Attack
00775 ; Computer Display. Its value is incremented every game loop iteration.
00776 ; Used in subroutine UPDATTCOMP ($A7BF). Used values are:
00777 ; $00..$04 -> Draw 0..4th row of blip shape
00778 ; $05..$09 -> Do not draw blip shape (delay)
00779 ; $0A -> Recalculate blip shape position, erase Attack Computer
00780 ; Display
00781 ;
00782 ; $A3 ISINLOCKON
00783 ;
00784 ; Indicates whether the tracked space object is currently in full
00785 ; lock-on (horizontally and vertically centered as well as in range) in
00786 ; the Attack Computer Display. If so, all lock-on markers show up on
00787 ; the Attack Computer Display and our starship's launched photon
00788 ; torpedoes will home in on the tracked space object. Used values are:
00789 ; $00 -> Not in lock-on
00790 ; $A0 -> In lock-on
00791 ;
00792 ; $A4 DIRLEN
00793 ;
00794 ; Used to pass the direction and length of a single line to be drawn in
00795 ; the PLAYFIELD. Used in subroutines DRAWLINES ($A76F), DRAWLINE
00796 ; ($A782), and UPDATTCOMP ($A7BF). Used values are:
00797 ; Bit B7 = 0 -> Draw right
00798 ; Bit B7 = 1 -> Draw down
00799 ; Bits B6..0 -> Length of line in pixels.
00800 ;
00801 ; See also PENROW ($A5) and PENCOLUMN ($A6).
00802 ;
00803 ; $A5 PENROW
00804 ;
00805 ; Used to pass the start screen pixel row number of the line to be
00806 ; drawn in the PLAYFIELD. Used in subroutines DRAWLINES ($A76F),
00807 ; DRAWLINE ($A782), and UPDATTCOMP ($A7BF).
00808 ;
00809 ; $A6 PENCOLUMN
00810 ;
00811 ; Used to pass the start screen pixel column number of the line to be
00812 ; drawn in the PLAYFIELD. Used in subroutines DRAWLINES ($A76F),
00813 ; DRAWLINE ($A782), and UPDATTCOMP ($A7BF).
00814 ;
00815 ; $A7 CTRLDZYLON
00816 ;
00817 ; Index of Zylon ship currently controlled by the game. Used in
00818 ; subroutine MANEUVER ($AA79). The value is toggled every other game
00819 ; loop iteration. Used values are:
00820 ; $00 -> Control Zylon ship 0.
00821 ; $01 -> Control Zylon ship 1.
00822 ;
00823 ; $A8 ZYLONFLPAT0
00824 ;
00825 ; Flight pattern of Zylon ship 0. Used in subroutine MANEUVER ($AA79).
00826 ; Used values are:
00827 ; $00 -> Attack flight pattern "0"
00828 ; $01 -> Flight pattern "1"
00829 ; $04 -> Flight pattern "4"
00830 ;
00831 ; $A9 ZYLONFLPAT1
00832 ;
00833 ; Flight pattern of Zylon ship 1. Compare ZYLONFLPAT0 ($A8).
00834 ;
00835 ; $AA MILESTTIM0
00836 ;
00837 ; Delay timer of the milestone velocity indices of Zylon ship 0. Used
00838 ; in subroutine MANEUVER ($AA79).
00839 ;
00840 ; When Zylon ship 0 is active, this value is decremented every game
00841 ; loop iteration. If it falls below 0 then the milestone velocity
00842 ; indices of Zylon ship 0 are recalculated. When Zylon ship 0 is
00843 ; controlled by the computer for the first time, the timer is set to an
00844 ; initial value of 1, later to an initial value of 120.
00845 ;
00846 ; $AB MILESTTIM1
00847 ;
00848 ; Delay timer of the milestone velocity index vector of Zylon ship 1.
00849 ; Compare MILESTTIM0 ($AA).
00850 ;
00851 ; $AC MILESTVELINDZ0
00852 ;
00853 ; Milestone z-velocity index of Zylon ship 0. Used in subroutine
00854 ; MANEUVER ($AA79). The current z-velocity index of Zylon ship 0
00855 ; ZYLONVELINDZ0 ($B2) is compared with this index and gradually
00856 ; adjusted to it. Used values are: 0..15.
00857 ;
00858 ; $AD MILESTVELINDZ1
00859 ;
00860 ; Milestone z-velocity index of Zylon ship 1. Compare MILESTVELINDZ0
00861 ; ($AC).
00862 ;
00863 ; $AE MILESTVELINDX0
00864 ;
00865 ; Milestone x-velocity index of Zylon ship 0. Used in subroutine
00866 ; MANEUVER ($AA79). The current x-velocity index of Zylon ship 0
00867 ; ZYLONVELINDX0 ($B4) is compared with this index and gradually
00868 ; adjusted to it. Used values are: 0..15.
00869 ;
00870 ; $AF MILESTVELINDX1
00871 ;
00872 ; Milestone x-velocity index of Zylon ship 1. Compare MILESTVELINDX0
00873 ; ($AE).
00874 ;
00875 ; $B0 MILESTVELINDY0
00876 ;
00877 ; Milestone y-velocity index of Zylon ship 0. Used in subroutine
00878 ; MANEUVER ($AA79). The current y-velocity index of Zylon ship 0
00879 ; ZYLONVELINDY0 ($B6) is compared with this index and gradually
00880 ; adjusted to it. Used values are: 0..15.
00881 ;
00882 ; $B1 MILESTVELINDY1
00883 ;
00884 ; Milestone y-velocity index of Zylon ship 1. Compare MILESTVELINDY0
00885 ; ($B0).
00886 ;
00887 ; $B2 ZYLONVELINDZ0
00888 ;
00889 ; Current z-velocity index of Zylon ship 0. Used in subroutine MANEUVER
00890 ; ($AA79). It indexes velocity values in ZYLONVELTAB ($BF99). Used
00891 ; values are: 0..15.
00892 ;
00893 ; $B3 ZYLONVELINDZ1
00894 ;
00895 ; Current z-velocity index of Zylon ship 1. Compare ZYLONVELINDZ0
00896 ; ($B2).
00897 ;
00898 ; $B4 ZYLONVELINDX0
00899 ;
00900 ; Current x-velocity index of Zylon ship 0. Compare ZYLONVELINDZ0
00901 ; ($B2).
00902 ;
00903 ; $B5 ZYLONVELINDX1
00904 ;
00905 ; Current x-velocity index of Zylon ship 1. Compare ZYLONVELINDZ0
00906 ; ($B2).
00907 ;
00908 ; $B6 ZYLONVELINDY0
00909 ;
00910 ; Current y-velocity index of Zylon ship 0. Compare ZYLONVELINDZ0
00911 ; ($B2).
00912 ;
00913 ; $B7 ZYLONVELINDY1
00914 ;
00915 ; Current y-velocity index of Zylon ship 1. Compare ZYLONVELINDZ0
00916 ; ($B2).
00917 ;
00918 ; $B8 ISBACKATTACK0
00919 ;
00920 ; Indicates whether Zylon ship 0 will attack our starship from the
00921 ; back. Used in subroutine MANEUVER ($AA79). Used values are:
00922 ; $00 -> Zylon ship 0 attacks from the front of our starship
00923 ; $01 -> Zylon ship 0 attacks from the front and back of our starship
00924 ;
00925 ; $B9 ISBACKATTACK1
00926 ;
00927 ; Indicates whether Zylon ship 1 will attack our starship from the
00928 ; back. Compare ISBACKATTACK0 ($B8).
00929 ;
00930 ; $BA ZYLONTIMX0
00931 ;
00932 ; Delay timer of the x-velocity index of Zylon ship 0. Used in
00933 ; subroutine MANEUVER ($AA79). It is decremented every game loop
00934 ; iteration. When the timer value falls below 0 the current velocity
00935 ; index ZYLONVELINDX0 ($B4) is adjusted depending on the current
00936 ; joystick position. The new timer value is set depending on the
00937 ; resulting new x-velocity index. Used values are: 0, 2, 4, ..., 14.
00938 ;
00939 ; $BB ZYLONTIMX1
00940 ;
00941 ; Delay timer of x-velocity index of Zylon ship 1. Compare ZYLONTIMX0
00942 ; ($BA).
00943 ;
00944 ; $BC ZYLONTIMY0
00945 ;
00946 ; Delay timer of y-velocity index of Zylon ship 0. Compare ZYLONTIMX0
00947 ; ($BA).
00948 ;
00949 ; $BD ZYLONTIMY1
00950 ;
00951 ; Delay timer of y-velocity index of Zylon ship 1. Compare ZYLONTIMX0
00952 ; ($BA).
00953 ;
00954 ; $BE TORPEDODELAY
00955 ;
00956 ; After a Zylon photon torpedo has hit our starship this delay timer is
00957 ; initialized to a value of 2. It is decremented every game loop
00958 ; iteration and so delays the launch of the next Zylon photon torpedo
00959 ; for 2 game loop iterations.
00960 ;
00961 ; $BF ZYLONATTACKER
00962 ;
00963 ; Index of the Zylon ship that launched the Zylon photon torpedo. It is
00964 ; used in GAMELOOP ($A1F3) to override the current tracking computer
00965 ; settings in order to track this Zylon ship first. Used values are:
00966 ; $00 -> Zylon photon torpedo was launched by Zylon ship 0
00967 ; $01 -> Zylon photon torpedo was launched by Zylon ship 1
00968 ;
00969 ; $C0 WARPSTATE
00970 ;
00971 ; Hyperwarp state. Used values are:
00972 ; $00 -> Hyperwarp not engaged
00973 ; $7F -> Hyperwarp engaged
00974 ; $FF -> In hyperspace
00975 ;
00976 ; $C1 VELOCITYHI
00977 ;
00978 ; Our starship's velocity (high byte) in <KM/H>. Used values are:
00979 ; $00 -> Not in hyperspace (regular cruise or accelerating to
00980 ; hyperspace velocity)
00981 ; $01 -> Hyperspace velocity
00982 ;
00983 ; See also VELOCITYLO ($70).
00984 ;
00985 ; $C2 TRAILDELAY
00986 ;
00987 ; Delay timer to create the next star trail. Its value is decremented
00988 ; from 3 to 0 every game loop iteration during the hyperwarp STAR TRAIL
00989 ; PHASE in subroutine INITTRAIL ($A9B4).
00990 ;
00991 ; $C3 TRAILIND
00992 ;
00993 ; Position vector index of the star trail's first star. Used in
00994 ; subroutine INITTRAIL ($A9B4) to initialize a star trail, which is
00995 ; then displayed during the hyperwarp STAR TRAIL PHASE. Used values
00996 ; are: 17..48 in wrap-around fashion.
00997 ;
00998 ; $C4 WARPTEMPCOLUMN
00999 ;
01000 ; Temporary arrival column number of our starship on the Galactic Chart
01001 ; at the beginning of hyperspace. It is given in Player/Missile pixels
01002 ; relative to the left Galactic Chart border. Divide this value by 8 to
01003 ; get the sector column number. Used values are: $00..$7F. See also
01004 ; WARPARRVCOLUMN ($8F).
01005 ;
01006 ; $C5 WARPTEMPROW
01007 ;
01008 ; Temporary arrival row number of our starship on the Galactic Chart at
01009 ; the beginning of hyperspace. It is given in Player/Missile pixels
01010 ; relative to top Galactic Chart border. Divide this value by 16 to get
01011 ; the sector row number. Used values are: $00..$7F. See also
01012 ; WARPARRVROW ($8E).
01013 ;
01014 ; $C6 VEERMASK
01015 ;
01016 ; Limits the veer-off velocity of the Hyperwarp Target Marker during
01017 ; the hyperwarp ACCELERATION PHASE in subroutine HYPERWARP ($A89B).
01018 ; Values are picked from table VEERMASKTAB ($BED7).
01019 ;
01020 ; Also used as a local variable.
01021 ;
01022 ; $C7 VICINITYMASK
01023 ;
01024 ; Mask to confine space objects' position vector components
01025 ; (coordinates) in a sector into a certain interval around our starship
01026 ; after its arrival from hyperspace. Values are picked from table
01027 ; VICINITYMASKTAB ($BFB3).
01028 ;
01029 ; $C8 JOYSTICKX
01030 ;
01031 ; Horizontal joystick direction. Values are picked from table
01032 ; STICKINCTAB ($BAF5). Used values are:
01033 ; $01 -> Right
01034 ; $00 -> Centered
01035 ; $FF -> Left
01036 ;
01037 ; $C9 JOYSTICKY
01038 ;
01039 ; Vertical joystick direction. Values are picked from table STICKINCTAB
01040 ; ($BAF5). Used values are:
01041 ; $01 -> Up
01042 ; $00 -> Centered
01043 ; $FF -> Down
01044 ;
01045 ; $CA KEYCODE
01046 ;
01047 ; Hardware keyboard code of the pressed key on the keyboard. Shift and
01048 ; Control key bits B7..6 are always set.
01049 ;
01050 ; $CB..$CC SCORE
01051 ;
01052 ; Internal 16-bit score of the game in low byte-high byte order
01053 ;
01054 ; $CD SCOREDRANKIND
01055 ;
01056 ; Scored Rank Index. It is translated with table RANKTAB ($BEE9) to a
01057 ; title phrase offset pointing to the rank string. Used values are:
01058 ; $00 -> GALACTIC COOK
01059 ; $01 -> GARBAGE SCOW CAPTAIN
01060 ; $02 -> GARBAGE SCOW CAPTAIN
01061 ; $03 -> ROOKIE
01062 ; $04 -> ROOKIE
01063 ; $05 -> NOVICE
01064 ; $06 -> NOVICE
01065 ; $07 -> ENSIGN
01066 ; $08 -> ENSIGN
01067 ; $09 -> PILOT
01068 ; $0A -> PILOT
01069 ; $0B -> ACE
01070 ; $0C -> LIEUTENANT
01071 ; $0D -> WARRIOR
01072 ; $0E -> CAPTAIN
01073 ; $0F -> COMMANDER
01074 ; $10 -> COMMANDER
01075 ; $11 -> STAR COMMANDER
01076 ; $12 -> STAR COMMANDER
01077 ;
01078 ; $CE SCOREDCLASSIND
01079 ;
01080 ; Scored Class Index. It is translated into a class number with table
01081 ; CLASSTAB ($BEFC). Used values are:
01082 ; $00 -> Class 5
01083 ; $01 -> Class 5
01084 ; $02 -> Class 5
01085 ; $03 -> Class 4
01086 ; $04 -> Class 4
01087 ; $05 -> Class 4
01088 ; $06 -> Class 4
01089 ; $07 -> Class 3
01090 ; $08 -> Class 3
01091 ; $09 -> Class 3
01092 ; $0A -> Class 2
01093 ; $0B -> Class 2
01094 ; $0C -> Class 2
01095 ; $0D -> Class 1
01096 ; $0E -> Class 1
01097 ; $0F -> Class 1
01098 ;
01099 ; $CF TITLELIFE
01100 ;
01101 ; Lifetime of title line. It is decremented every game loop iteration.
01102 ; Used initial values are:
01103 ; $3C -> When displaying regular title phrases
01104 ; $FE -> When displaying "STARBASE SURROUNDED", "STARBASE DESTOYED",
01105 ; and "RED ALERT" messages
01106 ; $FF -> Hide title line
01107 ;
01108 ; $D0 SHIPVIEW
01109 ;
01110 ; Current view of our starship. Values are picked from table
01111 ; VIEWMODETAB ($BE22). Used values are:
01112 ; $00 -> Front view
01113 ; $01 -> Aft view
01114 ; $40 -> Long-Range Scan view
01115 ; $80 -> Galactic Chart view
01116 ;
01117 ; $D1 TITLEPHR
01118 ;
01119 ; Title phrase offset for text phrase in title line. Used values are:
01120 ; $00..$7B -> Title phrase offset into PHRASETAB ($BBAA)
01121 ; $FF -> Hide title line
01122 ;
01123 ; See also NEWTITLEPHR ($65).
01124 ;
01125 ; $D2 BEEPFRQIND
01126 ;
01127 ; Beeper sound pattern: Running index into frequency table BEEPFRQTAB
01128 ; ($BF5C). See also BEEPFRQSTART ($D7). See also subroutines BEEP
01129 ; ($B3A6) and SOUND ($B2AB).
01130 ;
01131 ; $D3 BEEPREPEAT
01132 ;
01133 ; Beeper sound pattern: Number of times the beeper sound pattern is
01134 ; repeated - 1. See also subroutines BEEP ($B3A6) and SOUND ($B2AB).
01135 ;
01136 ; $D4 BEEPTONELIFE
01137 ;
01138 ; Beeper sound pattern: Lifetime of tone in TICKs - 1. See also
01139 ; subroutines BEEP ($B3A6) and SOUND ($B2AB).
01140 ;
01141 ; $D5 BEEPPAUSELIFE
01142 ;
01143 ; Beeper sound pattern: Lifetime of pause in TICKs - 1. Used values
01144 ; are:
01145 ; < $FF -> Number of TICKs - 1 to play
01146 ; $FF -> Skip playing pause
01147 ;
01148 ; See also subroutines BEEP ($B3A6) and SOUND ($B2AB).
01149 ;
01150 ; $D6 BEEPPRIORITY
01151 ;
01152 ; Beeper sound pattern: Pattern priority. Each beeper sound pattern has
01153 ; a priority. When a pattern of higher priority is about to be played
01154 ; the pattern that is currently playing is stopped. Used values are:
01155 ; $00 -> No pattern playing at the moment
01156 ; > $00 -> Pattern priority
01157 ;
01158 ; See also subroutines BEEP ($B3A6) and SOUND ($B2AB).
01159 ;
01160 ; $D7 BEEPFRQSTART
01161 ;
01162 ; Beeper sound pattern: Index to first byte of the pattern frequency in
01163 ; table BEEPFRQTAB ($BF5C). See also BEEPFRQIND ($D2). See also
01164 ; subroutines BEEP ($B3A6) and SOUND ($B2AB).
01165 ;
01166 ; $D8 BEEPLIFE
01167 ;
01168 ; Beeper sound pattern: Lifetime of the current tone or pause in TICKs.
01169 ; It is decremented every TICK. See also subroutines BEEP ($B3A6) and
01170 ; SOUND ($B2AB).
01171 ;
01172 ; $D9 BEEPTOGGLE
01173 ;
01174 ; Beeper sound pattern: Indicates that either a tone or a pause is
01175 ; currently played. Used values are:
01176 ; $00 -> Tone
01177 ; $01 -> Pause
01178 ;
01179 ; See also subroutines BEEP ($B3A6) and SOUND ($B2AB).
01180 ;
01181 ; $DA NOISETORPTIM
01182 ;
01183 ; Noise sound pattern: Delay timer for PHOTON TORPEDO LAUNCHED noise
01184 ; sound pattern. It is decremented every TICK. See also subroutines
01185 ; NOISE ($AEA8) and SOUND ($B2AB).
01186 ;
01187 ; $DB NOISEEXPLTIM
01188 ;
01189 ; Noise sound pattern: Delay timer for SHIELD EXPLOSION and ZYLON
01190 ; EXPLOSION noise sound pattern. It is decremented every TICK. See also
01191 ; subroutines NOISE ($AEA8) and SOUND ($B2AB).
01192 ;
01193 ; $DC NOISEAUDC2
01194 ;
01195 ; Noise sound pattern: Audio channel 1/2 control shadow register. See
01196 ; also subroutines NOISE ($AEA8) and SOUND ($B2AB).
01197 ;
01198 ; $DD NOISEAUDC3
01199 ;
01200 ; Noise sound pattern: Audio channel 3 control shadow register. See
01201 ; also subroutines NOISE ($AEA8) and SOUND ($B2AB).
01202 ;
01203 ; $DE NOISEAUDF1
01204 ;
01205 ; Noise sound pattern: Audio channel 1 frequency shadow register. See
01206 ; also subroutines NOISE ($AEA8) and SOUND ($B2AB).
01207 ;
01208 ; $DF NOISEAUDF2
01209 ;
01210 ; Noise sound pattern: Audio channel 2 frequency shadow register. See
01211 ; also subroutines NOISE ($AEA8) and SOUND ($B2AB).
01212 ;
01213 ; $E0 NOISEFRQINC
01214 ;
01215 ; Noise sound pattern: Audio channel 1/2 frequency increment. See also
01216 ; subroutines NOISE ($AEA8) and SOUND ($B2AB).
01217 ;
01218 ; $E1 NOISELIFE
01219 ;
01220 ; Noise sound pattern: Noise sound pattern lifetime. It is decremented
01221 ; every TICK. See also subroutines NOISE ($AEA8) and SOUND ($B2AB).
01222 ;
01223 ; $E2 NOISEZYLONTIM
01224 ;
01225 ; Delay timer to trigger the ZYLON EXPLOSION noise sound pattern. It is
01226 ; set in subroutine COLLISION ($AF3D) when an impact of one of our
01227 ; starship's photon torpedoes into a target is imminent. The timer is
01228 ; decremented every TICK during the execution of the Vertical Blank
01229 ; Interrupt handler VBIHNDLR ($A6D1). When the timer value reaches 0
01230 ; the ZYLON EXPLOSION noise sound pattern is played in subroutine SOUND
01231 ; ($B2AB).
01232 ;
01233 ; $E3 NOISEHITLIFE
01234 ;
01235 ; Lifetime of STARSHIP EXPLOSION noise when our starship was destroyed
01236 ; by a Zylon photon torpedo. It is set in routine GAMELOOP ($A1F3) to a
01237 ; value of 64 TICKs. It is decremented every TICK during the execution
01238 ; of the Vertical Blank Interrupt handler VBIHNDLR ($A6D1).
01239 ;
01240 ; $E4 PL0SHAPOFF
01241 ;
01242 ; PLAYER0 offset into shape table PLSHAP2TAB ($B9B1)
01243 ;
01244 ; $E5 PL1SHAPOFF
01245 ;
01246 ; PLAYER1 offset into shape table PLSHAP2TAB ($B9B1)
01247 ;
01248 ; $E6 PL2SHAPOFF
01249 ;
01250 ; PLAYER2 offset into shape table PLSHAP1TAB ($B8E4)
01251 ;
01252 ; $E7 PL3SHAPOFF
01253 ;
01254 ; PLAYER3 offset into shape table PLSHAP1TAB ($B8E4)
01255 ;
01256 ; $E8 PL4SHAPOFF
01257 ;
01258 ; PLAYER4 offset into shape table PLSHAP1TAB ($B8E4)
01259 ;
01260 ; $E9 PL0LIFE
01261 ;
01262 ; Lifetime of the space object represented by PLAYER0 (usually Zylon
01263 ; ship 0). Any value other than $FF is decremented with every game loop
01264 ; iteration. Used values are:
01265 ; $00 -> Space object not alive (= not in use)
01266 ; $01..$FE -> Values during lifetime countdown
01267 ; $FF -> Infinite lifetime (not counted down)
01268 ;
01269 ; $EA PL1LIFE
01270 ;
01271 ; Lifetime of a space object represented by PLAYER1 (usually Zylon ship
01272 ; 1). Compare PL0LIFE ($E9).
01273 ;
01274 ; $EB PL2LIFE
01275 ;
01276 ; Lifetime of a space object represented by PLAYER2 (usually the Zylon
01277 ; photon torpedo). Compare PL0LIFE ($E9).
01278 ;
01279 ; If this PLAYER represents a photon torpedo, its lifetime is
01280 ; decremented from an initial value of $FF.
01281 ;
01282 ; $EC PL3LIFE
01283 ;
01284 ; Lifetime of a space object represented by PLAYER3 (usually our
01285 ; starship's photon torpedo 0). Compare PL2LIFE ($EB).
01286 ;
01287 ; If this PLAYER represents a photon torpedo, its lifetime is
01288 ; decremented from an initial value of $FF.
01289 ;
01290 ; $ED PL4LIFE
01291 ;
01292 ; Lifetime of a space object represented by PLAYER4 (usually our
01293 ; starship's photon torpedo 1). Compare PL2LIFE ($EB).
01294 ;
01295 ; If this PLAYER represents a photon torpedo, its lifetime is
01296 ; decremented from an initial value of $FF.
01297 ;
01298 ; $EE PL0COLOR
01299 ;
01300 ; Color of PLAYER0
01301 ;
01302 ; $EF PL1COLOR
01303 ;
01304 ; Color of PLAYER1
01305 ;
01306 ; $F0 PL2COLOR
01307 ;
01308 ; Color of PLAYER2
01309 ;
01310 ; $F1 PL3COLOR
01311 ;
01312 ; Color of PLAYER3
01313 ;
01314 ; $F2 PF0COLOR
01315 ;
01316 ; Color of PLAYFIELD0
01317 ;
01318 ; $F3 PF1COLOR
01319 ;
01320 ; Color of PLAYFIELD1
01321 ;
01322 ; $F4 PF2COLOR
01323 ;
01324 ; Color of PLAYFIELD2
01325 ;
01326 ; $F5 PF3COLOR
01327 ;
01328 ; Color of PLAYFIELD3
01329 ;
01330 ; $F6 BGRCOLOR
01331 ;
01332 ; Color of BACKGROUND
01333 ;
01334 ; $F7 PF0COLORDLI
01335 ;
01336 ; Color of PLAYFIELD0 after DLI
01337 ;
01338 ; $F8 PF1COLORDLI
01339 ;
01340 ; Color of PLAYFIELD1 after DLI
01341 ;
01342 ; $F9 PF2COLORDLI
01343 ;
01344 ; Color of PLAYFIELD2 after DLI
01345 ;
01346 ; $FA PF3COLORDLI
01347 ;
01348 ; Color of PLAYFIELD3 after DLI
01349 ;
01350 ; $FB BGRCOLORDLI
01351 ;
01352 ; Color of BACKGROUND after DLI
01353 ;
01354 ; $0280..$02E9 DSPLST
01355 ;
01356 ; Display List
01357 ;
01358 ; $0300..$03FF PL4DATA
01359 ;
01360 ; PLAYER4 data area
01361 ;
01362 ; $0400..$04FF PL0DATA
01363 ;
01364 ; PLAYER0 data area
01365 ;
01366 ; $0500..$05FF PL1DATA
01367 ;
01368 ; PLAYER1 data area
01369 ;
01370 ; $0600..$06FF PL2DATA
01371 ;
01372 ; PLAYER2 data area
01373 ;
01374 ; $0700..$07FF PL3DATA
01375 ;
01376 ; PLAYER3 data area
01377 ;
01378 ; $0800..$0863 PFMEMROWLO
01379 ;
01380 ; Lookup table of start addresses (low byte) for each row of
01381 ; PLAYFIELD memory, which is located at PFMEM ($1000). The table
01382 ; contains 100 bytes for 100 rows (of which only 99 are shown by
01383 ; the Display List, the PLAYFIELD is 160 x 99 pixels). The
01384 ; addresses grow in increments of 40 (40 bytes = 160 pixels in
01385 ; GRAPHICS7 mode = 1 PLAYFIELD row of pixels). See also PFMEMROWHI
01386 ; ($0864).
01387 ;
01388 ; $0864..$08C7 PFMEMROWHI
01389 ;
01390 ; Lookup table of start addresses (high byte) of each row of
01391 ; PLAYFIELD memory. See also PFMEMROWLO ($0800).
01392 ;
01393 ; $08C9..$0948 GCMEMMAP
01394 ;
01395 ; Galactic Chart memory map (16 columns x 8 rows = 128 bytes)
01396 ;
01397 ; $0949..$0970 PANELTXT
01398 ;
01399 ; Memory of Control Panel Display (bottom text window) in Front
01400 ; view, Aft view, and Long-Range Scan view (20 characters x 2 rows
01401 ; = 40 bytes).
01402 ;
01403 ; $094A VELOCD1
01404 ;
01405 ; First digit (of 2) of the VELOCITY readout in Control Panel
01406 ; Display memory.
01407 ;
01408 ; $0950 KILLCNTD1
01409 ;
01410 ; First digit (of 2) of the KILL COUNTER readout in Control Panel
01411 ; Display memory.
01412 ;
01413 ; $0955 ENERGYD1
01414 ;
01415 ; First digit (of 4) of the ENERGY readout in Control Panel Display
01416 ; memory.
01417 ;
01418 ; $095A TRACKC1
01419 ;
01420 ; Character of the TRACKING readout 'T' or 'C' in Control Panel
01421 ; Display memory.
01422 ;
01423 ; $095C TRACKDIGIT
01424 ;
01425 ; Digit of the TRACKING readout in Control Panel Display memory. It
01426 ; is used to store the index of the currently tracked space object.
01427 ; Used values are:
01428 ; $00 -> Track Zylon ship 0
01429 ; $01 -> Track Zylon ship 1
01430 ; $02 -> Track starbase
01431 ; $03 -> Track Hyperwarp Target Marker
01432 ;
01433 ; $0960 THETAC1
01434 ;
01435 ; First character of the THETA readout in Control Panel Display
01436 ; memory.
01437 ;
01438 ; $0966 PHIC1
01439 ;
01440 ; First character of the PHI readout in Control Panel Display
01441 ; memory.
01442 ;
01443 ; $096C RANGEC1
01444 ;
01445 ; First character of the RANGE readout in Control Panel Display
01446 ; memory.
01447 ;
01448 ; $0971..$09AC GCTXT
01449 ;
01450 ; Memory of Galactic Chart Panel Display (bottom text window) of
01451 ; Galactic Chart view (20 characters x 3 rows = 60 bytes).
01452 ;
01453 ; $097D GCWARPD1
01454 ;
01455 ; First digit (of 4) of the HYPERWARP ENERGY readout in Galactic
01456 ; Chart Panel Display memory.
01457 ;
01458 ; $098D GCTRGCNT
01459 ;
01460 ; First target counter digit (of 2) in Galactic Chart Panel Display
01461 ; memory.
01462 ;
01463 ; $0992 GCSTATPHO
01464 ;
01465 ; Photon Torpedo status letter in Galactic Chart Panel Display
01466 ; memory. Used values are:
01467 ; %00****** -> OK
01468 ; %10****** -> Destroyed
01469 ; %11****** -> Damaged
01470 ;
01471 ; $0993 GCSTATENG
01472 ;
01473 ; Engines status letter in Galactic Chart Panel Display memory.
01474 ; Used values are:
01475 ; %00****** -> OK
01476 ; %10****** -> Destroyed
01477 ; %11****** -> Damaged
01478 ;
01479 ; $0994 GCSTATSHL
01480 ;
01481 ; Shields status letter in Galactic Chart Panel Display memory.
01482 ; Used values are:
01483 ; %00****** -> OK
01484 ; %10****** -> Destroyed
01485 ; %11****** -> Damaged
01486 ;
01487 ; $0995 GCSTATCOM
01488 ;
01489 ; Attack Computer status letter in Galactic Chart Panel Display
01490 ; memory. Used values are:
01491 ; %00****** -> OK
01492 ; %10****** -> Destroyed
01493 ; %11****** -> Damaged
01494 ;
01495 ; $0996 GCSTATLRS
01496 ;
01497 ; Long-Range Scan status letter in Galactic Chart Panel Display
01498 ; memory. Used values are:
01499 ; %00****** -> OK
01500 ; %10****** -> Destroyed
01501 ; %11****** -> Damaged
01502 ;
01503 ; $0997 GCSTATRAD
01504 ;
01505 ; Subspace Radio status letter in Galactic Chart Panel Display
01506 ; memory. Used values are:
01507 ; %00****** -> OK
01508 ; %10****** -> Destroyed
01509 ; %11****** -> Damaged
01510 ;
01511 ; $09A3 GCSTARDAT
01512 ;
01513 ; First (of 5) digits of the star date clock in the Galactic Chart
01514 ; Panel Display memory.
01515 ;
01516 ; $09AD..$09DD ZPOSSIGN
01517 ;
01518 ; Table containing the sign bit (B16) of position vector
01519 ; z-components (z-coordinate) (49 bytes). Bytes 0..4 belong to
01520 ; position vectors of PLAYER space objects (Zylon ships, photon
01521 ; torpedoes, etc.). Bytes 5..48 belong to position vectors of
01522 ; PLAYFIELD space objects (stars, explosion fragments). Used values
01523 ; are:
01524 ; $00 -> Negative sign (behind our starship)
01525 ; $01 -> Positive sign (in front of our starship)
01526 ;
01527 ; See also "ON POSITION VECTORS".
01528 ;
01529 ; $09AD PL0ZPOSSIGN
01530 ;
01531 ; Sign bit (B16) of position vector z-component (z-coordinate) of
01532 ; PLAYER0. Compare ZPOSSIGN ($09AD). See also "ON POSITION
01533 ; VECTORS".
01534 ;
01535 ; $09AE PL1ZPOSSIGN
01536 ;
01537 ; Sign bit (B16) of position vector z-component (z-coordinate) of
01538 ; PLAYER1. Compare ZPOSSIGN ($09AD). See also "ON POSITION
01539 ; VECTORS".
01540 ;
01541 ; $09AF PL2ZPOSSIGN
01542 ;
01543 ; Sign bit (B16) of position vector z-component (z-coordinate) of
01544 ; PLAYER2. Compare ZPOSSIGN ($09AD). See also "ON POSITION
01545 ; VECTORS".
01546 ;
01547 ; $09B0 PL3ZPOSSIGN
01548 ;
01549 ; Sign bit (B16) of position vector z-component (z-coordinate) of
01550 ; PLAYER3. Compare ZPOSSIGN ($09AD). See also "ON POSITION
01551 ; VECTORS".
01552 ;
01553 ; $09B1 PL4ZPOSSIGN
01554 ;
01555 ; Sign bit (B16) of position vector z-component (z-coordinate) of
01556 ; PLAYER4. Compare ZPOSSIGN ($09AD). See also "ON POSITION
01557 ; VECTORS".
01558 ;
01559 ; $09DE..$0A0E XPOSSIGN
01560 ;
01561 ; Table containing the sign bit (B16) of position vector
01562 ; x-components (x-coordinate) (49 bytes). Bytes 0..4 belong to
01563 ; position vectors of PLAYER space objects (Zylon ships, photon
01564 ; torpedoes, etc.). Bytes 5..48 belong to position vectors of
01565 ; PLAYFIELD space objects (stars, explosion fragments). Used values
01566 ; are:
01567 ; $00 -> Negative sign (left)
01568 ; $01 -> Positive sign (right)
01569 ;
01570 ; See also "ON POSITION VECTORS".
01571 ;
01572 ; $09DE PL0XPOSSIGN
01573 ;
01574 ; Sign bit (B16) of position vector x-component (x-coordinate) of
01575 ; PLAYER0. Compare XPOSSIGN ($09DE). See also "ON POSITION
01576 ; VECTORS".
01577 ;
01578 ; $09DF PL1XPOSSIGN
01579 ;
01580 ; Sign bit (B16) of position vector x-component (x-coordinate) of
01581 ; PLAYER1. Compare XPOSSIGN ($09DE). See also "ON POSITION
01582 ; VECTORS".
01583 ;
01584 ; $09E0 PL2XPOSSIGN
01585 ;
01586 ; Sign bit (B16) of position vector x-component (x-coordinate) of
01587 ; PLAYER2. Compare XPOSSIGN ($09DE). See also "ON POSITION
01588 ; VECTORS".
01589 ;
01590 ; $09E1 PL3XPOSSIGN
01591 ;
01592 ; Sign bit (B16) of position vector x-component (x-coordinate) of
01593 ; PLAYER3. Compare XPOSSIGN ($09DE). See also "ON POSITION
01594 ; VECTORS".
01595 ;
01596 ; $09E2 PL4XPOSSIGN
01597 ;
01598 ; Sign bit (B16) of position vector x-component (x-coordinate) of
01599 ; PLAYER4. Compare XPOSSIGN ($09DE). See also "ON POSITION
01600 ; VECTORS".
01601 ;
01602 ; $0A0F..$0A3F YPOSSIGN
01603 ;
01604 ; Table containing the sign bit (B16) of position vector
01605 ; y-components (y-coordinate) (49 bytes). Bytes 0..4 belong to
01606 ; position vectors of PLAYER space objects (Zylon ships, photon
01607 ; torpedoes, etc.). Bytes 5..48 belong to position vectors of
01608 ; PLAYFIELD space objects (stars, explosion fragments). Used values
01609 ; are:
01610 ; $00 -> Negative sign (down)
01611 ; $01 -> Positive sign (up)
01612 ;
01613 ; See also "ON POSITION VECTORS".
01614 ;
01615 ; $0A0F PL0YPOSSIGN
01616 ;
01617 ; Sign bit (B16) of position vector y-component (y-coordinate) of
01618 ; PLAYER0. Compare YPOSSIGN ($0A0F). See also "ON POSITION
01619 ; VECTORS".
01620 ;
01621 ; $0A10 PL1YPOSSIGN
01622 ;
01623 ; Sign bit (B16) of position vector y-component (y-coordinate) of
01624 ; PLAYER1. Compare YPOSSIGN ($0A0F). See also "ON POSITION
01625 ; VECTORS".
01626 ;
01627 ; $0A11 PL2YPOSSIGN
01628 ;
01629 ; Sign bit (B16) of position vector y-component (y-coordinate) of
01630 ; PLAYER2. Compare YPOSSIGN ($0A0F). See also "ON POSITION
01631 ; VECTORS".
01632 ;
01633 ; $0A12 PL3YPOSSIGN
01634 ;
01635 ; Sign bit (B16) of position vector y-component (y-coordinate) of
01636 ; PLAYER3. Compare YPOSSIGN ($0A0F). See also "ON POSITION
01637 ; VECTORS".
01638 ;
01639 ; $0A13 PL4YPOSSIGN
01640 ;
01641 ; Sign bit (B16) of position vector y-component (y-coordinate) of
01642 ; PLAYER4. Compare YPOSSIGN ($0A0F). See also "ON POSITION
01643 ; VECTORS".
01644 ;
01645 ; $0A40..$0A70 ZPOSHI
01646 ;
01647 ; Table containing the high byte (B15..8) of position vector
01648 ; y-components (y-coordinate) (49 bytes). Bytes 0..4 belong to
01649 ; position vectors of PLAYER space objects (Zylon ships, photon
01650 ; torpedoes, etc.). Bytes 5..48 belong to position vectors of
01651 ; PLAYFIELD space objects (stars, explosion fragments). See also
01652 ; "ON POSITION VECTORS".
01653 ;
01654 ; $0A40 PL0ZPOSHI
01655 ;
01656 ; High byte (B15..8) of position vector z-component (z-coordinate)
01657 ; of PLAYER0. Compare ZPOSHI ($0A40). See also "ON POSITION
01658 ; VECTORS".
01659 ;
01660 ; $0A41 PL1ZPOSHI
01661 ;
01662 ; High byte (B15..8) of position vector z-component (z-coordinate)
01663 ; of PLAYER1. Compare ZPOSHI ($0A40). See also "ON POSITION
01664 ; VECTORS".
01665 ;
01666 ; $0A42 PL2ZPOSHI
01667 ;
01668 ; High byte (B15..8) of position vector z-component (z-coordinate)
01669 ; of PLAYER2. Compare ZPOSHI ($0A40). See also "ON POSITION
01670 ; VECTORS".
01671 ;
01672 ; $0A43 PL3ZPOSHI
01673 ;
01674 ; High byte (B15..8) of position vector z-component (z-coordinate)
01675 ; of PLAYER3. Compare ZPOSHI ($0A40). See also "ON POSITION
01676 ; VECTORS".
01677 ;
01678 ; $0A44 PL4ZPOSHI
01679 ;
01680 ; High byte (B15..8) of position vector z-component (z-coordinate)
01681 ; of PLAYER4. Compare ZPOSHI ($0A40). See also "ON POSITION
01682 ; VECTORS".
01683 ;
01684 ; $0A71..$0AA1 XPOSHI
01685 ;
01686 ; Table containing the high byte (B15..8) of position vector
01687 ; x-components (x-coordinate) (49 bytes). Bytes 0..4 belong to
01688 ; position vectors of PLAYER space objects (Zylon ships, photon
01689 ; torpedoes, etc.). Bytes 5..48 belong to position vectors of
01690 ; PLAYFIELD space objects (stars, explosion fragments). See also
01691 ; "ON POSITION VECTORS".
01692 ;
01693 ; $0A71 PL0XPOSHI
01694 ;
01695 ; High byte (B15..8) of position vector x-component (x-coordinate)
01696 ; of PLAYER0. Compare XPOSHI ($0A71). See also "ON POSITION
01697 ; VECTORS".
01698 ;
01699 ; $0A72 PL1XPOSHI
01700 ;
01701 ; High byte (B15..8) of position vector x-component (x-coordinate)
01702 ; of PLAYER1. Compare XPOSHI ($0A71). See also "ON POSITION
01703 ; VECTORS".
01704 ;
01705 ; $0A73 PL2XPOSHI
01706 ;
01707 ; High byte (B15..8) of position vector x-component (x-coordinate)
01708 ; of PLAYER2. Compare XPOSHI ($0A71). See also "ON POSITION
01709 ; VECTORS".
01710 ;
01711 ; $0A74 PL3XPOSHI
01712 ;
01713 ; High byte (B15..8) of position vector x-component (x-coordinate)
01714 ; of PLAYER3. Compare XPOSHI ($0A71). See also "ON POSITION
01715 ; VECTORS".
01716 ;
01717 ; $0A75 PL4XPOSHI
01718 ;
01719 ; High byte (B15..8) of position vector x-component (x-coordinate)
01720 ; of PLAYER4. Compare XPOSHI ($0A71). See also "ON POSITION
01721 ; VECTORS".
01722 ;
01723 ; $0AA2..$0AD2 YPOSHI
01724 ;
01725 ; Table containing the high byte (B15..8) of position vector
01726 ; y-components (y-coordinate) (49 bytes). Bytes 0..4 belong to
01727 ; position vectors of PLAYER space objects (Zylon ships, photon
01728 ; torpedoes, etc.). Bytes 5..48 belong to position vectors of
01729 ; PLAYFIELD space objects (stars, explosion fragments). See also
01730 ; "ON POSITION VECTORS".
01731 ;
01732 ; $0AA2 PL0YPOSHI
01733 ;
01734 ; High byte (B15..8) of position vector y-component (y-coordinate)
01735 ; of PLAYER0. Compare YPOSHI ($0AA2). See also "ON POSITION
01736 ; VECTORS".
01737 ;
01738 ; $0AA3 PL1YPOSHI
01739 ;
01740 ; High byte (B15..8) of position vector y-component (y-coordinate)
01741 ; of PLAYER1. Compare YPOSHI ($0AA2). See also "ON POSITION
01742 ; VECTORS".
01743 ;
01744 ; $0AA4 PL2YPOSHI
01745 ;
01746 ; High byte (B15..8) of position vector y-component (y-coordinate)
01747 ; of PLAYER2. Compare YPOSHI ($0AA2). See also "ON POSITION
01748 ; VECTORS".
01749 ;
01750 ; $0AA5 PL3YPOSHI
01751 ;
01752 ; High byte (B15..8) of position vector y-component (y-coordinate)
01753 ; of PLAYER3. Compare YPOSHI ($0AA2). See also "ON POSITION
01754 ; VECTORS".
01755 ;
01756 ; $0AA6 PL4YPOSHI
01757 ;
01758 ; High byte (B15..8) of position vector y-component (y-coordinate)
01759 ; of PLAYER4. Compare YPOSHI ($0AA2). See also "ON POSITION
01760 ; VECTORS".
01761 ;
01762 ; $0AD3..$0B03 ZPOSLO
01763 ;
01764 ; Table containing the low byte (B7..0) of position vector
01765 ; z-components (z-coordinate) (49 bytes). Bytes 0..4 belong to
01766 ; position vectors of PLAYER space objects (Zylon ships, photon
01767 ; torpedoes, etc.). Bytes 5..48 belong to position vectors of
01768 ; PLAYFIELD space objects (stars, explosion fragments). See also
01769 ; "ON POSITION VECTORS".
01770 ;
01771 ; $0AD3 PL0ZPOSLO
01772 ;
01773 ; Low byte (B7..0) of position vector z-component (z-coordinate) of
01774 ; PLAYER0. Compare ZPOSLO ($0AD3). See also "ON POSITION VECTORS".
01775 ;
01776 ; $0AD4 PL1ZPOSLO
01777 ;
01778 ; Low byte (B7..0) of position vector z-component (z-coordinate) of
01779 ; PLAYER1. Compare ZPOSLO ($0AD3). See also "ON POSITION VECTORS".
01780 ;
01781 ; $0AD5 PL2ZPOSLO
01782 ;
01783 ; Low byte (B7..0) of position vector z-component (z-coordinate) of
01784 ; PLAYER2. Compare ZPOSLO ($0AD3). See also "ON POSITION VECTORS".
01785 ;
01786 ; $0AD6 PL3ZPOSLO
01787 ;
01788 ; Low byte (B7..0) of position vector z-component (z-coordinate) of
01789 ; PLAYER3. Compare ZPOSLO ($0AD3). See also "ON POSITION VECTORS".
01790 ;
01791 ; $0AD7 PL4ZPOSLO
01792 ;
01793 ; Low byte (B7..0) of position vector z-component (z-coordinate) of
01794 ; PLAYER4. Compare ZPOSLO ($0AD3). See also "ON POSITION VECTORS".
01795 ;
01796 ; $0B04..$0B34 XPOSLO
01797 ;
01798 ; Table containing the low byte (B7..0) of position vector
01799 ; x-components (x-coordinate) (49 bytes). Bytes 0..4 belong to
01800 ; position vectors of PLAYER space objects (Zylon ships, photon
01801 ; torpedoes, etc.). Bytes 5..48 belong to position vectors of
01802 ; PLAYFIELD space objects (stars, explosion fragments). See also
01803 ; "ON POSITION VECTORS".
01804 ;
01805 ; $0B04 PL0XPOSLO
01806 ;
01807 ; Low byte (B7..0) of position vector x-component (x-coordinate) of
01808 ; PLAYER0. Compare XPOSLO ($0B04). See also "ON POSITION VECTORS".
01809 ;
01810 ; $0B05 PL1XPOSLO
01811 ;
01812 ; Low byte (B7..0) of position vector x-component (x-coordinate) of
01813 ; PLAYER1. Compare XPOSLO ($0B04). See also "ON POSITION VECTORS".
01814 ;
01815 ; $0B06 PL2XPOSLO
01816 ;
01817 ; Low byte (B7..0) of position vector x-component (x-coordinate) of
01818 ; PLAYER2. Compare XPOSLO ($0B04). See also "ON POSITION VECTORS".
01819 ;
01820 ; $0B07 PL3XPOSLO
01821 ;
01822 ; Low byte (B7..0) of position vector x-component (x-coordinate) of
01823 ; PLAYER3. Compare XPOSLO ($0B04). See also "ON POSITION VECTORS".
01824 ;
01825 ; $0B08 PL4XPOSLO
01826 ;
01827 ; Low byte (B7..0) of position vector x-component (x-coordinate) of
01828 ; PLAYER4. Compare XPOSLO ($0B04). See also "ON POSITION VECTORS".
01829 ;
01830 ; $0B35..$0B65 YPOSLO
01831 ;
01832 ; Table containing the low byte (B7..0) of position vector
01833 ; y-components (y-coordinate) (49 bytes). Bytes 0..4 belong to
01834 ; position vectors of PLAYER space objects (Zylon ships, photon
01835 ; torpedoes, etc.). Bytes 5..48 belong to position vectors of
01836 ; PLAYFIELD space objects (stars, explosion fragments). See also
01837 ; "ON POSITION VECTORS".
01838 ;
01839 ; $0B35 PL0YPOSLO
01840 ;
01841 ; Low byte (B7..0) of position vector y-component (y-coordinate) of
01842 ; PLAYER0. Compare YPOSLO ($0B35). See also "ON POSITION VECTORS".
01843 ;
01844 ; $0B36 PL1YPOSLO
01845 ;
01846 ; Low byte (B7..0) of position vector y-component (y-coordinate) of
01847 ; PLAYER1. Compare YPOSLO ($0B35). See also "ON POSITION VECTORS".
01848 ;
01849 ; $0B37 PL2YPOSLO
01850 ;
01851 ; Low byte (B7..0) of position vector y-component (y-coordinate) of
01852 ; PLAYER2. Compare YPOSLO ($0B35). See also "ON POSITION VECTORS".
01853 ;
01854 ; $0B38 PL3YPOSLO
01855 ;
01856 ; Low byte (B7..0) of position vector y-component (y-coordinate) of
01857 ; PLAYER3. Compare YPOSLO ($0B35). See also "ON POSITION VECTORS".
01858 ;
01859 ; $0B39 PL4YPOSLO
01860 ;
01861 ; Low byte (B7..0) of position vector y-component (y-coordinate) of
01862 ; PLAYER4. Compare YPOSLO ($0B35). See also "ON POSITION VECTORS".
01863 ;
01864 ; $0B66..$0B96 ZVEL
01865 ;
01866 ; Table containing velocity vector z-components (z-velocities) (49
01867 ; bytes). Bytes 0..4 belong to velocity vectors of PLAYER space
01868 ; objects (Zylon ships, photon torpedoes, etc.). Bytes 5..48 belong
01869 ; to velocity vectors of PLAYFIELD space objects (stars, explosion
01870 ; fragments). Each z-velocity is stored in the binary format
01871 ; %sxxxxxxx where
01872 ; %s = 0 -> Positive sign (moving in flight direction)
01873 ; %s = 1 -> Negative sign (moving in reverse flight direction)
01874 ; %xxxxxxx -> Unsigned 7-bit velocity value in <KM/H>
01875 ;
01876 ; See also "ON VELOCITY VECTORS".
01877 ;
01878 ; $0B66 PL0ZVEL
01879 ;
01880 ; Velocity vector z-component (z-velocity) of PLAYER0. Compare ZVEL
01881 ; ($0B66). See also "ON VELOCITY VECTORS".
01882 ;
01883 ; $0B67 PL1ZVEL
01884 ;
01885 ; Velocity vector z-component (z-velocity) of PLAYER1. Compare ZVEL
01886 ; ($0B66). See also "ON VELOCITY VECTORS".
01887 ;
01888 ; $0B68 PL2ZVEL
01889 ;
01890 ; Velocity vector z-component (z-velocity) of PLAYER2. Compare ZVEL
01891 ; ($0B66). See also "ON VELOCITY VECTORS".
01892 ;
01893 ; $0B69 PL3ZVEL
01894 ;
01895 ; Velocity vector z-component (z-velocity) of PLAYER3. Compare ZVEL
01896 ; ($0B66). See also "ON VELOCITY VECTORS".
01897 ;
01898 ; $0B6A PL4ZVEL
01899 ;
01900 ; Velocity vector z-component (z-velocity) of PLAYER4. Compare ZVEL
01901 ; ($0B66). See also "ON VELOCITY VECTORS".
01902 ;
01903 ; $0B97..$0BC7 XVEL
01904 ;
01905 ; Table containing velocity vector x-components (x-velocities) (49
01906 ; bytes). Bytes 0..4 belong to velocity vectors of PLAYER space
01907 ; objects (Zylon ships, photon torpedoes, etc.). Bytes 5..48 belong
01908 ; to velocity vectors of PLAYFIELD space objects (stars, explosion
01909 ; fragments). Each x-velocity is stored in the binary format
01910 ; %sxxxxxxx where
01911 ; %s = 0 -> Positive sign (moving to the right)
01912 ; %s = 1 -> Negative sign (moving to the left)
01913 ; %xxxxxxx -> Unsigned 7-bit velocity value in <KM/H>
01914 ;
01915 ; See also "ON VELOCITY VECTORS".
01916 ;
01917 ; $0B97 PL0XVEL
01918 ;
01919 ; Velocity vector x-component (x-velocity) of PLAYER0. Compare XVEL
01920 ; ($0B97). See also "ON VELOCITY VECTORS".
01921 ;
01922 ; $0B98 PL1XVEL
01923 ;
01924 ; Velocity vector x-component (x-velocity) of PLAYER1. Compare XVEL
01925 ; ($0B97). See also "ON VELOCITY VECTORS".
01926 ;
01927 ; $0B99 PL2XVEL
01928 ;
01929 ; Velocity vector x-component (x-velocity) of PLAYER2. Compare XVEL
01930 ; ($0B97). See also "ON VELOCITY VECTORS".
01931 ;
01932 ; $0B9A PL3XVEL
01933 ;
01934 ; Velocity vector x-component (x-velocity) of PLAYER3. Compare XVEL
01935 ; ($0B97). See also "ON VELOCITY VECTORS".
01936 ;
01937 ; $0B9B PL4XVEL
01938 ;
01939 ; Velocity vector x-component (x-velocity) of PLAYER4. Compare XVEL
01940 ; ($0B97). See also "ON VELOCITY VECTORS".
01941 ;
01942 ; $0BC8..$0BF8 YVEL
01943 ;
01944 ; Table containing velocity vector y-components (y-velocities) (49
01945 ; bytes). Bytes 0..4 belong to velocity vectors of PLAYER space
01946 ; objects (Zylon ships, photon torpedoes, etc.). Bytes 5..48 belong
01947 ; to velocity vectors of PLAYFIELD space objects (stars, explosion
01948 ; fragments). Each y-velocity is stored in the binary format
01949 ; %sxxxxxxx where
01950 ; %s = 0 -> Positive sign (moving up)
01951 ; %s = 1 -> Negative sign (moving down)
01952 ; %xxxxxxx -> Unsigned 7-bit velocity value in <KM/H>
01953 ;
01954 ; See also "ON VELOCITY VECTORS".
01955 ;
01956 ; $0BC8 PL0YVEL
01957 ;
01958 ; Velocity vector y-component (y-velocity) of PLAYER0. Compare YVEL
01959 ; ($0BC8). See also "ON VELOCITY VECTORS".
01960 ;
01961 ; $0BC9 PL1YVEL
01962 ;
01963 ; Velocity vector y-component (y-velocity) of PLAYER1. Compare YVEL
01964 ; ($0BC8). See also "ON VELOCITY VECTORS".
01965 ;
01966 ; $0BCA PL2YVEL
01967 ;
01968 ; Velocity vector y-component (y-velocity) of PLAYER2. Compare YVEL
01969 ; ($0BC8). See also "ON VELOCITY VECTORS".
01970 ;
01971 ; $0BCB PL3YVEL
01972 ;
01973 ; Velocity vector y-component (y-velocity) of PLAYER3. Compare YVEL
01974 ; ($0BC8). See also "ON VELOCITY VECTORS".
01975 ;
01976 ; $0BCC PL4YVEL
01977 ;
01978 ; Velocity vector y-component (y-velocity) of PLAYER4. Compare YVEL
01979 ; ($0BC8). See also "ON VELOCITY VECTORS".
01980 ;
01981 ; $0BF9..$0C29 PIXELROWNEW
01982 ;
01983 ; Table containing the new pixel row number of space objects (49
01984 ; bytes). Bytes 0..4 belong to PLAYER space objects and contain
01985 ; Player/Missile (PM) pixel row numbers. They are counted from
01986 ; vertical PM position 0, which is offscreen. Bytes 5..48 belong to
01987 ; PLAYFIELD space objects (stars, explosion fragments) and contain
01988 ; PLAYFIELD pixel row numbers. They are counted from the top border
01989 ; of the PLAYFIELD and have values of 0..99. See also PIXELROW
01990 ; ($0C5B).
01991 ;
01992 ; $0BF9 PL0ROWNEW
01993 ;
01994 ; New pixel row number of PLAYER0 in Player/Missile pixels. See
01995 ; also PIXELROWNEW ($0BF9).
01996 ;
01997 ; $0BFA PL1ROWNEW
01998 ;
01999 ; New pixel row number of PLAYER1 in Player/Missile pixels. See
02000 ; also PIXELROWNEW ($0BF9).
02001 ;
02002 ; $0BFB PL2ROWNEW
02003 ;
02004 ; New pixel row number of PLAYER2 in Player/Missile pixels. See
02005 ; also PIXELROWNEW ($0BF9).
02006 ;
02007 ; $0BFC PL3ROWNEW
02008 ;
02009 ; New pixel row number of PLAYER3 in Player/Missile pixels. See
02010 ; also PIXELROWNEW ($0BF9).
02011 ;
02012 ; $0BFD PL4ROWNEW
02013 ;
02014 ; New pixel row number of PLAYER4 in Player/Missile pixels. See
02015 ; also PIXELROWNEW ($0BF9).
02016 ;
02017 ; $0C2A..$0C5A PIXELCOLUMN
02018 ;
02019 ; Table containing the pixel column number of space objects (49
02020 ; bytes). Bytes 0..4 belong to PLAYER space objects and contain
02021 ; Player/Missile (PM) pixel column numbers. They are counted from
02022 ; horizontal PM position 0, which is offscreen. Bytes 5..48 belong
02023 ; to PLAYFIELD space objects (stars, explosion fragments) and
02024 ; contain PLAYFIELD pixel column numbers. They are counted from the
02025 ; left border of the PLAYFIELD and have values of 0..159.
02026 ;
02027 ; $0C2A PL0COLUMN
02028 ;
02029 ; Pixel column number of PLAYER0 in Player/Missile pixels. See also
02030 ; PIXELCOLUMN ($0C2A).
02031 ;
02032 ; $0C2B PL1COLUMN
02033 ;
02034 ; Pixel column number of PLAYER1 in Player/Missile pixels. See also
02035 ; PIXELCOLUMN ($0C2A).
02036 ;
02037 ; $0C2C PL2COLUMN
02038 ;
02039 ; Pixel column number of PLAYER2 in Player/Missile pixels. See also
02040 ; PIXELCOLUMN ($0C2A).
02041 ;
02042 ; $0C2D PL3COLUMN
02043 ;
02044 ; Pixel column number of PLAYER3 in Player/Missile pixels. See also
02045 ; PIXELCOLUMN ($0C2A).
02046 ;
02047 ; $0C2E PL4COLUMN
02048 ;
02049 ; Pixel column number of PLAYER4 in Player/Missile pixels. See also
02050 ; PIXELCOLUMN ($0C2A).
02051 ;
02052 ; $0C5B..$0C8B PIXELROW
02053 ;
02054 ; Table containing the pixel row number of space objects (49
02055 ; bytes). Bytes 0..4 belong to PLAYER space objects and contain
02056 ; Player/Missile (PM) pixel row numbers. They are counted from
02057 ; vertical PM position 0, which is offscreen. Bytes 5..48 belong to
02058 ; PLAYFIELD space objects (stars, explosion fragments) and contain
02059 ; PLAYFIELD pixel row numbers. They are counted from the top border
02060 ; of the PLAYFIELD and have values of 0..99. See also PIXELROWNEW
02061 ; ($0BF9).
02062 ;
02063 ; $0C5B PL0ROW
02064 ;
02065 ; Pixel row number of PLAYER0 in Player/Missile pixels. See also
02066 ; PIXELROW ($0C5B).
02067 ;
02068 ; $0C5C PL1ROW
02069 ;
02070 ; Pixel row number of PLAYER1 in Player/Missile pixels. See also
02071 ; PIXELROW ($0C5B).
02072 ;
02073 ; $0C5D PL2ROW
02074 ;
02075 ; Pixel row number of PLAYER2 in Player/Missile pixels. See also
02076 ; PIXELROW ($0C5B).
02077 ;
02078 ; $0C5E PL3ROW
02079 ;
02080 ; Pixel row number of PLAYER3 in Player/Missile pixels. See also
02081 ; PIXELROW ($0C5B).
02082 ;
02083 ; $0C5F PL4ROW
02084 ;
02085 ; Pixel row number of PLAYER4 in Player/Missile pixels. See also
02086 ; PIXELROW ($0C5B).
02087 ;
02088 ; $0C8C..$0CBC PIXELBYTEOFF
02089 ;
02090 ; Table containing a byte offset into PLAYFIELD memory for each
02091 ; PLAYFIELD space object (stars, explosion fragments) (49 bytes):
02092 ; the number of bytes from the start of the PLAYFIELD row to the
02093 ; byte containing the space object pixel in the same PLAYFIELD row.
02094 ; In other words, the pixel column modulo 4 (1 byte = 4 GRAPHICS7
02095 ; pixels).
02096 ;
02097 ; NOTE: Only bytes 5..48 are used for PLAYFIELD space objects in
02098 ; this way. Bytes 0..4 are used differently. See PL0SHAPTYPE
02099 ; ($0C8C)..PL4SHAPTYPE ($0C90).
02100 ;
02101 ; $0C8C PL0SHAPTYPE
02102 ;
02103 ; Shape type of PLAYER0. Used to index the PLAYER's set of shape
02104 ; cells in tables PLSHAPOFFTAB ($BE2F) and PLSHAPHEIGHTTAB ($BE7F).
02105 ; Used values are:
02106 ; $00 -> PHOTON TORPEDO
02107 ; $10 -> ZYLON FIGHTER
02108 ; $20 -> STARBASE RIGHT
02109 ; $30 -> STARBASE CENTER
02110 ; $40 -> STARBASE LEFT
02111 ; $50 -> TRANSFER VESSEL
02112 ; $60 -> METEOR
02113 ; $70 -> ZYLON CRUISER
02114 ; $80 -> ZYLON BASESTAR
02115 ; $90 -> HYPERWARP TARGET MARKER
02116 ;
02117 ; $0C8D PL1SHAPTYPE
02118 ;
02119 ; Shape type of PLAYER1. Compare PL0SHAPTYPE ($0C8C).
02120 ;
02121 ; $0C8E PL2SHAPTYPE
02122 ;
02123 ; Shape type of PLAYER2. Compare PL0SHAPTYPE ($0C8C).
02124 ;
02125 ; $0C8F PL3SHAPTYPE
02126 ;
02127 ; Shape type of PLAYER3. Compare PL0SHAPTYPE ($0C8C).
02128 ;
02129 ; $0C90 PL4SHAPTYPE
02130 ;
02131 ; Shape type of PLAYER4. Compare PL0SHAPTYPE ($0C8C).
02132 ;
02133 ; $0CBD..$0CED PIXELSAVE
02134 ;
02135 ; Table containing the byte of PLAYFIELD memory before drawing the
02136 ; PLAYFIELD space object pixel into it (star, explosion fragments),
02137 ; for each PLAYFIELD space object (49 bytes).
02138 ;
02139 ; NOTE: Only bytes 5..48 are used for PLAYFIELD space objects in
02140 ; this way. Bytes 0..4 are used differently. See PL0HEIGHT
02141 ; ($0CBD)..PL4HEIGHT ($0CC1).
02142 ;
02143 ; $0CBD PL0HEIGHT
02144 ;
02145 ; Shape height of PLAYER0
02146 ;
02147 ; $0CBE PL1HEIGHT
02148 ;
02149 ; Shape height of PLAYER1
02150 ;
02151 ; $0CBF PL2HEIGHT
02152 ;
02153 ; Shape height of PLAYER2
02154 ;
02155 ; $0CC0 PL3HEIGHT
02156 ;
02157 ; Shape height of PLAYER3
02158 ;
02159 ; $0CC1 PL4HEIGHT
02160 ;
02161 ; Shape height of PLAYER4
02162 ;
02163 ; $0CEE..$0D1E PIXELBYTE
02164 ;
02165 ; Table containing a 1-byte bit pattern for 4 pixels in the color
02166 ; of the space object's pixel, for each PLAYFIELD space object (49
02167 ; bytes).
02168 ;
02169 ; NOTE: Only bytes 5..48 are used for PLAYFIELD space objects in
02170 ; this way. Bytes 0..4 are used differently. See PL0HEIGHTNEW
02171 ; ($0CEE)..PL4HEIGHTNEW ($0CF2).
02172 ;
02173 ; $0CEE PL0HEIGHTNEW
02174 ;
02175 ; New shape height of PLAYER0
02176 ;
02177 ; $0CEF PL1HEIGHTNEW
02178 ;
02179 ; New shape height of PLAYER1
02180 ;
02181 ; $0CF0 PL2HEIGHTNEW
02182 ;
02183 ; New shape height of PLAYER2
02184 ;
02185 ; $0CF1 PL3HEIGHTNEW
02186 ;
02187 ; New shape height of PLAYER3
02188 ;
02189 ; $0CF2 PL4HEIGHTNEW
02190 ;
02191 ; New shape height of PLAYER4
02192 ;
02193 ; $0D1F..$0D32 TITLETXT
02194 ;
02195 ; Title text line, contains ATASCII-coded characters (20 bytes)
02196 ;
02197 ; $0D35..$0DE8 GCPFMEM
02198 ;
02199 ; Galactic Chart PLAYFIELD memory (20 characters x 9 rows = 180
02200 ; bytes)
02201 ;
02202 ; $0DE9..$0EE8 MAPTO80
02203 ;
02204 ; Lookup table to convert values in $00..$FF to values of 0..80
02205 ; (255 bytes). Used to map position vector components (coordinates)
02206 ; to pixel row or column numbers relative to the PLAYFIELD center.
02207 ;
02208 ; $0EE9..$0FE8 MAPTOBCD99
02209 ;
02210 ; Lookup table to convert values in $00..$FF to BCD-values of
02211 ; 00..99 (255 bytes). Used in subroutines UPDPANEL ($B804) and
02212 ; SHOWDIGITS ($B8CD) to convert values to a 2-digit decimal readout
02213 ; value of the Control Panel Display.
02214 ;
02215 ; $1000..$1F77 PFMEM
02216 ;
02217 ; PLAYFIELD graphics memory (40 bytes x 100 rows = 4000 bytes, 1
02218 ; byte stores 4 pixels, 40 bytes = 160 pixels in GRAPHICS7 mode = 1
02219 ; PLAYFIELD row of pixels).
02220 ;
02221 ; NOTE: The Display List displays only PLAYFIELD rows 0..98.
02222
02223 ;*******************************************************************************
02224 ;* *
02225 ;* S Y S T E M S Y M B O L S *
02226 ;* *
02227 ;*******************************************************************************
02228
=0200 02229 VDSLST = $0200 ; Display List Interrupt (DLI) vector
=0216 02230 VIMIRQ = $0216 ; Interrupt request (IRQ) immediate vector
=0222 02231 VVBLKI = $0222 ; Vertical blank immediate vector
=D000 02232 HPOSP0 = $D000 ; Horizontal position of PLAYER0
=D001 02233 HPOSP1 = $D001 ; Horizontal position of PLAYER1
=D002 02234 HPOSP2 = $D002 ; Horizontal position of PLAYER2
=D003 02235 HPOSP3 = $D003 ; Horizontal position of PLAYER3
=D004 02236 HPOSM0 = $D004 ; Horizontal position of MISSILE0
=D005 02237 HPOSM1 = $D005 ; Horizontal position of MISSILE1
=D006 02238 HPOSM2 = $D006 ; Horizontal position of MISSILE2
=D007 02239 HPOSM3 = $D007 ; Horizontal position of MISSILE3
=D008 02240 M0PL = $D008 ; MISSILE0 to PLAYER collisions
=D009 02241 M1PL = $D009 ; MISSILE1 to PLAYER collisions
=D00A 02242 M2PL = $D00A ; MISSILE2 to PLAYER collisions
=D00B 02243 M3PL = $D00B ; MISSILE3 to PLAYER collisions
=D00F 02244 P3PL = $D00F ; PLAYER3 to PLAYER collisions
=D010 02245 TRIG0 = $D010 ; Joystick 0 trigger
=D012 02246 COLPM0 = $D012 ; Color and brightness of PLAYER0
=D016 02247 COLPF0 = $D016 ; Color and brightness of PLAYFIELD0
=D01B 02248 PRIOR = $D01B ; Priority selection register
=D01D 02249 GRACTL = $D01D ; Graphics control register
=D01E 02250 HITCLR = $D01E ; Clear collision register
=D01F 02251 CONSOL = $D01F ; Function keys register
=D200 02252 AUDF1 = $D200 ; Audio channel 1 frequency
=D202 02253 AUDF2 = $D202 ; Audio channel 2 frequency
=D203 02254 AUDC2 = $D203 ; Audio channel 2 control
=D204 02255 AUDF3 = $D204 ; Audio channel 3 frequency
=D205 02256 AUDC3 = $D205 ; Audio channel 3 control
=D206 02257 AUDF4 = $D206 ; Audio channel 4 frequency
=D207 02258 AUDC4 = $D207 ; Audio channel 4 control
=D208 02259 AUDCTL = $D208 ; Audio control
=D209 02260 KBCODE = $D209 ; Keyboard code
=D209 02261 STIMER = $D209 ; Start POKEY timers
=D20A 02262 RANDOM = $D20A ; Random number generator
=D20E 02263 IRQEN = $D20E ; Interrupt request (IRQ) enable
=D20F 02264 SKCTL = $D20F ; Serial port control
=D300 02265 PORTA = $D300 ; Port A
=D302 02266 PACTL = $D302 ; Port A control
=D400 02267 DMACTL = $D400 ; Direct Memory Access (DMA) control
=D402 02268 DLIST = $D402 ; Display List pointer
=D407 02269 PMBASE = $D407 ; Player/Missile base address (high byte)
=D409 02270 CHBASE = $D409 ; Character set base address (high byte)
=D40A 02271 WSYNC = $D40A ; Wait for horizontal synchronization
=D40B 02272 VCOUNT = $D40B ; Vertical line counter
=D40E 02273 NMIEN = $D40E ; Non-maskable interrupt (NMI) enable
=E000 02274 ROMCHARSET = $E000 ; ROM character set
02275
02276 ;*******************************************************************************
02277 ;* *
02278 ;* G A M E S Y M B O L S *
02279 ;* *
02280 ;*******************************************************************************
02281
=0062 02282 MISSIONLEVEL = $62
=0063 02283 FKEYCODE = $63
=0064 02284 ISDEMOMODE = $64
=0065 02285 NEWTITLEPHR = $65
=0066 02286 IDLECNTHI = $66
=0067 02287 ISVBISYNC = $67
=0068 02288 MEMPTR = $68
02289
=006A 02290 DIVIDEND = $6A
=006D 02291 JOYSTICKDELTA = $6D
02292
02293
=0070 02294 VELOCITYLO = $70
=0071 02295 NEWVELOCITY = $71
=0072 02296 COUNT8 = $72
=0073 02297 EXPLLIFE = $73
=0074 02298 CLOCKTIM = $74
=0075 02299 DOCKSTATE = $75
=0076 02300 COUNT256 = $76
=0077 02301 IDLECNTLO = $77
=0078 02302 ZYLONUNITTIM = $78
=0079 02303 MAXSPCOBJIND = $79
=007A 02304 OLDMAXSPCOBJIND = $7A
=007B 02305 ISSTARBASESECT = $7B
=007C 02306 ISTRACKCOMPON = $7C
=007D 02307 DRAINSHIELDS = $7D
=007E 02308 DRAINATTCOMP = $7E
=007F 02309 ENERGYCNT = $7F
=0080 02310 DRAINENGINES = $80
=0081 02311 SHIELDSCOLOR = $81
=0082 02312 PL3HIT = $82
=0083 02313 PL4HIT = $83
=0084 02314 OLDTRIG0 = $84
02315
=0086 02316 ISTRACKING = $86
=0087 02317 BARRELNR = $87
=0088 02318 LOCKONLIFE = $88
=0089 02319 PLTRACKED = $89
=008A 02320 HITBADNESS = $8A
=008B 02321 REDALERTLIFE = $8B
=008C 02322 WARPDEPRROW = $8C
=008D 02323 WARPDEPRCOLUMN = $8D
=008E 02324 WARPARRVROW = $8E
=008F 02325 WARPARRVCOLUMN = $8F
=0090 02326 CURRSECTOR = $90
=0091 02327 WARPENERGY = $91
=0092 02328 ARRVSECTOR = $92
=0093 02329 HUNTSECTOR = $93
=0094 02330 HUNTSECTCOLUMN = $94
=0095 02331 HUNTSECTROW = $95
=0096 02332 NEWZYLONDIST = $96
=009E 02333 OLDZYLONDIST = $9E
=009F 02334 HUNTTIM = $9F
=00A0 02335 BLIPCOLUMN = $A0
=00A1 02336 BLIPROW = $A1
=00A2 02337 BLIPCYCLECNT = $A2
=00A3 02338 ISINLOCKON = $A3
=00A4 02339 DIRLEN = $A4
=00A5 02340 PENROW = $A5
=00A6 02341 PENCOLUMN = $A6
=00A7 02342 CTRLDZYLON = $A7
=00A8 02343 ZYLONFLPAT0 = $A8
=00A9 02344 ZYLONFLPAT1 = $A9
=00AA 02345 MILESTTIM0 = $AA
=00AB 02346 MILESTTIM1 = $AB
=00AC 02347 MILESTVELINDZ0 = $AC
=00AD 02348 MILESTVELINDZ1 = $AD
=00AE 02349 MILESTVELINDX0 = $AE
=00AF 02350 MILESTVELINDX1 = $AF
=00B0 02351 MILESTVELINDY0 = $B0
=00B1 02352 MILESTVELINDY1 = $B1
=00B2 02353 ZYLONVELINDZ0 = $B2
=00B3 02354 ZYLONVELINDZ1 = $B3
=00B4 02355 ZYLONVELINDX0 = $B4
=00B5 02356 ZYLONVELINDX1 = $B5
=00B6 02357 ZYLONVELINDY0 = $B6
=00B7 02358 ZYLONVELINDY1 = $B7
=00B8 02359 ISBACKATTACK0 = $B8
=00B9 02360 ISBACKATTACK1 = $B9
=00BA 02361 ZYLONTIMX0 = $BA
=00BB 02362 ZYLONTIMX1 = $BB
=00BC 02363 ZYLONTIMY0 = $BC
=00BD 02364 ZYLONTIMY1 = $BD
=00BE 02365 TORPEDODELAY = $BE
=00BF 02366 ZYLONATTACKER = $BF
=00C0 02367 WARPSTATE = $C0
=00C1 02368 VELOCITYHI = $C1
=00C2 02369 TRAILDELAY = $C2
=00C3 02370 TRAILIND = $C3
=00C4 02371 WARPTEMPCOLUMN = $C4
=00C5 02372 WARPTEMPROW = $C5
=00C6 02373 VEERMASK = $C6
=00C7 02374 VICINITYMASK = $C7
=00C8 02375 JOYSTICKX = $C8
=00C9 02376 JOYSTICKY = $C9
=00CA 02377 KEYCODE = $CA
=00CB 02378 SCORE = $CB
=00CD 02379 SCOREDRANKIND = $CD
=00CE 02380 SCOREDCLASSIND = $CE
=00CF 02381 TITLELIFE = $CF
=00D0 02382 SHIPVIEW = $D0
=00D1 02383 TITLEPHR = $D1
=00D2 02384 BEEPFRQIND = $D2
=00D3 02385 BEEPREPEAT = $D3
=00D4 02386 BEEPTONELIFE = $D4
=00D5 02387 BEEPPAUSELIFE = $D5
=00D6 02388 BEEPPRIORITY = $D6
=00D7 02389 BEEPFRQSTART = $D7
=00D8 02390 BEEPLIFE = $D8
=00D9 02391 BEEPTOGGLE = $D9
=00DA 02392 NOISETORPTIM = $DA
=00DB 02393 NOISEEXPLTIM = $DB
=00DC 02394 NOISEAUDC2 = $DC
=00DD 02395 NOISEAUDC3 = $DD
=00DE 02396 NOISEAUDF1 = $DE
=00DF 02397 NOISEAUDF2 = $DF
=00E0 02398 NOISEFRQINC = $E0
=00E1 02399 NOISELIFE = $E1
=00E2 02400 NOISEZYLONTIM = $E2
=00E3 02401 NOISEHITLIFE = $E3
=00E4 02402 PL0SHAPOFF = $E4
=00E5 02403 PL1SHAPOFF = $E5
=00E6 02404 PL2SHAPOFF = $E6
=00E7 02405 PL3SHAPOFF = $E7
=00E8 02406 PL4SHAPOFF = $E8
=00E9 02407 PL0LIFE = $E9
=00EA 02408 PL1LIFE = $EA
=00EB 02409 PL2LIFE = $EB
=00EC 02410 PL3LIFE = $EC
=00ED 02411 PL4LIFE = $ED
=00EE 02412 PL0COLOR = $EE
=00EF 02413 PL1COLOR = $EF
=00F0 02414 PL2COLOR = $F0
=00F1 02415 PL3COLOR = $F1
=00F2 02416 PF0COLOR = $F2
=00F3 02417 PF1COLOR = $F3
=00F4 02418 PF2COLOR = $F4
=00F5 02419 PF3COLOR = $F5
=00F6 02420 BGRCOLOR = $F6
=00F7 02421 PF0COLORDLI = $F7
=00F8 02422 PF1COLORDLI = $F8
=00F9 02423 PF2COLORDLI = $F9
=00FA 02424 PF3COLORDLI = $FA
=00FB 02425 BGRCOLORDLI = $FB
=0280 02426 DSPLST = $0280
=0300 02427 PL4DATA = $0300
=0400 02428 PL0DATA = $0400
=0500 02429 PL1DATA = $0500
=0600 02430 PL2DATA = $0600
=0700 02431 PL3DATA = $0700
=0800 02432 PFMEMROWLO = $0800
=0864 02433 PFMEMROWHI = $0864
=08C9 02434 GCMEMMAP = $08C9
=0949 02435 PANELTXT = $0949
=094B 02436 VELOCD1 = $094B
=0950 02437 KILLCNTD1 = $0950
=0955 02438 ENERGYD1 = $0955
=095A 02439 TRACKC1 = $095A
=095C 02440 TRACKDIGIT = $095C
=0960 02441 THETAC1 = $0960
=0966 02442 PHIC1 = $0966
=096C 02443 RANGEC1 = $096C
=0971 02444 GCTXT = $0971
=097D 02445 GCWARPD1 = $097D
=098D 02446 GCTRGCNT = $098D
=0992 02447 GCSTATPHO = $0992
=0993 02448 GCSTATENG = $0993
=0994 02449 GCSTATSHL = $0994
=0995 02450 GCSTATCOM = $0995
=0996 02451 GCSTATLRS = $0996
=0997 02452 GCSTATRAD = $0997
=09A3 02453 GCSTARDAT = $09A3
=09AD 02454 ZPOSSIGN = $09AD
=09AF 02455 PL2ZPOSSIGN = $09AF
=09B0 02456 PL3ZPOSSIGN = $09B0
=09B1 02457 PL4ZPOSSIGN = $09B1
=09DE 02458 XPOSSIGN = $09DE
=09E0 02459 PL2XPOSSIGN = $09E0
=09E1 02460 PL3XPOSSIGN = $09E1
=09E2 02461 PL4XPOSSIGN = $09E2
=0A0F 02462 YPOSSIGN = $0A0F
=0A11 02463 PL2YPOSSIGN = $0A11
=0A12 02464 PL3YPOSSIGN = $0A12
=0A13 02465 PL4YPOSSIGN = $0A13
=0A40 02466 ZPOSHI = $0A40
=0A40 02467 PL0ZPOSHI = $0A40
=0A42 02468 PL2ZPOSHI = $0A42
=0A43 02469 PL3ZPOSHI = $0A43
=0A44 02470 PL4ZPOSHI = $0A44
=0A71 02471 XPOSHI = $0A71
=0A73 02472 PL2XPOSHI = $0A73
=0A74 02473 PL3XPOSHI = $0A74
=0A75 02474 PL4XPOSHI = $0A75
=0AA2 02475 YPOSHI = $0AA2
=0AA4 02476 PL2YPOSHI = $0AA4
=0AA5 02477 PL3YPOSHI = $0AA5
=0AA6 02478 PL4YPOSHI = $0AA6
=0AD3 02479 ZPOSLO = $0AD3
=0AD5 02480 PL2ZPOSLO = $0AD5
=0AD6 02481 PL3ZPOSLO = $0AD6
=0AD7 02482 PL4ZPOSLO = $0AD7
=0B04 02483 XPOSLO = $0B04
=0B06 02484 PL2XPOSLO = $0B06
=0B07 02485 PL3XPOSLO = $0B07
=0B08 02486 PL4XPOSLO = $0B08
=0B35 02487 YPOSLO = $0B35
=0B37 02488 PL2YPOSLO = $0B37
=0B38 02489 PL3YPOSLO = $0B38
=0B39 02490 PL4YPOSLO = $0B39
=0B66 02491 ZVEL = $0B66
=0B66 02492 PL0ZVEL = $0B66
=0B67 02493 PL1ZVEL = $0B67
=0B68 02494 PL2ZVEL = $0B68
=0B69 02495 PL3ZVEL = $0B69
=0B6A 02496 PL4ZVEL = $0B6A
=0B97 02497 XVEL = $0B97
=0B97 02498 PL0XVEL = $0B97
=0B98 02499 PL1XVEL = $0B98
=0B99 02500 PL2XVEL = $0B99
=0B9A 02501 PL3XVEL = $0B9A
=0B9B 02502 PL4XVEL = $0B9B
=0BC8 02503 YVEL = $0BC8
=0BC8 02504 PL0YVEL = $0BC8
=0BC9 02505 PL1YVEL = $0BC9
=0BCA 02506 PL2YVEL = $0BCA
=0BCB 02507 PL3YVEL = $0BCB
=0BCC 02508 PL4YVEL = $0BCC
=0BF9 02509 PIXELROWNEW = $0BF9
=0BF9 02510 PL0ROWNEW = $0BF9
=0BFA 02511 PL1ROWNEW = $0BFA
=0BFB 02512 PL2ROWNEW = $0BFB
=0BFC 02513 PL3ROWNEW = $0BFC
=0BFD 02514 PL4ROWNEW = $0BFD
=0C2A 02515 PIXELCOLUMN = $0C2A
=0C2A 02516 PL0COLUMN = $0C2A
=0C2B 02517 PL1COLUMN = $0C2B
=0C2C 02518 PL2COLUMN = $0C2C
=0C2D 02519 PL3COLUMN = $0C2D
=0C2E 02520 PL4COLUMN = $0C2E
=0C5B 02521 PIXELROW = $0C5B
=0C5B 02522 PL0ROW = $0C5B
=0C5C 02523 PL1ROW = $0C5C
=0C5D 02524 PL2ROW = $0C5D
=0C5E 02525 PL3ROW = $0C5E
=0C5F 02526 PL4ROW = $0C5F
=0C8C 02527 PIXELBYTEOFF = $0C8C
=0C8C 02528 PL0SHAPTYPE = $0C8C
=0C8D 02529 PL1SHAPTYPE = $0C8D
=0C8E 02530 PL2SHAPTYPE = $0C8E
=0C8F 02531 PL3SHAPTYPE = $0C8F
=0C90 02532 PL4SHAPTYPE = $0C90
=0CBD 02533 PIXELSAVE = $0CBD
=0CBD 02534 PL0HEIGHT = $0CBD
=0CBE 02535 PL1HEIGHT = $0CBE
=0CBF 02536 PL2HEIGHT = $0CBF
=0CC0 02537 PL3HEIGHT = $0CC0
=0CC1 02538 PL4HEIGHT = $0CC1
=0CEE 02539 PIXELBYTE = $0CEE
=0CEE 02540 PL0HEIGHTNEW = $0CEE
=0CEF 02541 PL1HEIGHTNEW = $0CEF
=0CF0 02542 PL2HEIGHTNEW = $0CF0
=0CF1 02543 PL3HEIGHTNEW = $0CF1
=0CF2 02544 PL4HEIGHTNEW = $0CF2
=0D1F 02545 TITLETXT = $0D1F
=0D35 02546 GCPFMEM = $0D35
=0DE9 02547 MAPTO80 = $0DE9
=0EE9 02548 MAPTOBCD99 = $0EE9
=1000 02549 PFMEM = $1000
02550
02551 *= $A000
02552
02553 ;*******************************************************************************
02554 ;* *
02555 ;* G A M E D A T A ( P A R T 1 O F 2 ) *
02556 ;* *
02557 ;*******************************************************************************
02558
02559 ;*** Number of space objects ***************************************************
02560
=0005 02561 NUMSPCOBJ.PL = 5 ; Number of PLAYER space objects
=000C 02562 NUMSPCOBJ.STARS = 12 ; Number of PLAYFIELD space objects (stars)
=0011 02563 NUMSPCOBJ.NORM = NUMSPCOBJ.PL+NUMSPCOBJ.STARS ; Normal number of space objects
=0031 02564 NUMSPCOBJ.ALL = 49 ; Maximum number of space objects
02565
02566 ;*** PLAYER shape data offsets *************************************************
02567
=0000 02568 SHAP.TORPEDO = $00 ; Photon torpedo
=0010 02569 SHAP.ZFIGHTER = $10 ; Zylon fighter
=0020 02570 SHAP.STARBASEL = $20 ; Starbase (left part)
=0030 02571 SHAP.STARBASEC = $30 ; Starbase (center part)
=0040 02572 SHAP.STARBASER = $40 ; Starbase (right part)
=0050 02573 SHAP.TRANSVSSL = $50 ; Transfer vessel
=0060 02574 SHAP.METEOR = $60 ; Meteor
=0070 02575 SHAP.ZCRUISER = $70 ; Zylon cruiser
=0080 02576 SHAP.ZBASESTAR = $80 ; Zylon basestar
=0090 02577 SHAP.HYPERWARP = $90 ; Hyperwarp Target Marker
02578
02579 ;*** ROM character set constants ***********************************************
=0000 02580 ROM.SPC = $00 ; ROM character ' '
=000E 02581 ROM.DOT = $0E ; ROM character '.'
=0010 02582 ROM.0 = $10 ; ROM character '0'
=0011 02583 ROM.1 = $11 ; ROM character '1'
=0012 02584 ROM.2 = $12 ; ROM character '2'
=0013 02585 ROM.3 = $13 ; ROM character '3'
=0014 02586 ROM.4 = $14 ; ROM character '4'
=0015 02587 ROM.5 = $15 ; ROM character '5'
=0019 02588 ROM.9 = $19 ; ROM character '9'
=001A 02589 ROM.COLON = $1A ; ROM character ':'
=0021 02590 ROM.A = $21 ; ROM character 'A'
=0023 02591 ROM.C = $23 ; ROM character 'C'
=0024 02592 ROM.D = $24 ; ROM character 'D'
=0025 02593 ROM.E = $25 ; ROM character 'E'
=0027 02594 ROM.G = $27 ; ROM character 'G'
=002C 02595 ROM.L = $2C ; ROM character 'L'
=002E 02596 ROM.N = $2E ; ROM character 'N'
=0030 02597 ROM.P = $30 ; ROM character 'P'
=0032 02598 ROM.R = $32 ; ROM character 'R'
=0033 02599 ROM.S = $33 ; ROM character 'S'
=0034 02600 ROM.T = $34 ; ROM character 'T'
=0037 02601 ROM.W = $37 ; ROM character 'W'
=0039 02602 ROM.Y = $39 ; ROM character 'Y'
02603
02604 ;*** Custom character set constants ********************************************
=0040 02605 CCS.COL1 = $40 ; COLOR1 bits for text in GR1/2 text mode
=0080 02606 CCS.COL2 = $80 ; COLOR2 bits for text in GR1/2 text mode
=00C0 02607 CCS.COL3 = $C0 ; COLOR3 bits for text in GR1/2 text mode
02608
=0000 02609 CCS.0 = 0 ; Custom character '0'
=0001 02610 CCS.1 = 1 ; Custom character '1'
=0002 02611 CCS.2 = 2 ; Custom character '2'
=0003 02612 CCS.3 = 3 ; Custom character '3'
=0004 02613 CCS.4 = 4 ; Custom character '4'
=0005 02614 CCS.5 = 5 ; Custom character '5'
=0006 02615 CCS.6 = 6 ; Custom character '6'
=0007 02616 CCS.7 = 7 ; Custom character '7'
=0008 02617 CCS.8 = 8 ; Custom character '8'
=0009 02618 CCS.9 = 9 ; Custom character '9'
=000A 02619 CCS.SPC = 10 ; Custom character ' '
=000B 02620 CCS.COLON = 11 ; Custom character ':'
=000C 02621 CCS.BORDERSW = 12 ; Custom character 'BORDER SOUTHWEST'
=000D 02622 CCS.E = 13 ; Custom character 'E'
=000E 02623 CCS.INF = 14 ; Custom character 'INFINITY'
=000F 02624 CCS.MINUS = 15 ; Custom character '-'
=0010 02625 CCS.PLUS = 16 ; Custom character '+'
=0011 02626 CCS.PHI = 17 ; Custom character 'PHI'
=0012 02627 CCS.V = 18 ; Custom character 'V'
=0013 02628 CCS.R = 19 ; Custom character 'R'
=0014 02629 CCS.THETA = 20 ; Custom character 'THETA'
=0015 02630 CCS.K = 21 ; Custom character 'K'
=0016 02631 CCS.T = 22 ; Custom character 'T'
=0017 02632 CCS.C = 23 ; Custom character 'C'
=0018 02633 CCS.BORDERS = 24 ; Custom character 'BORDER SOUTH'
=0019 02634 CCS.BORDERW = 25 ; Custom character 'BORDER WEST'
=001A 02635 CCS.CORNERSW = 26 ; Custom character 'CORNER SOUTHWEST'
=001B 02636 CCS.STARBASE = 27 ; Custom character 'STARBASE SECTOR'
=001C 02637 CCS.4ZYLONS = 28 ; Custom character '4-ZYLON SECTOR'
=001D 02638 CCS.3ZYLONS = 29 ; Custom character '3-ZYLON SECTOR'
=001E 02639 CCS.2ZYLONS = 30 ; Custom character '2-ZYLON SECTOR'
02640
02641 ;*** Custom character set ******************************************************
02642 ;
02643 ; 0 1 2 3 4 5 6 7
02644 ; ........ ........ ........ ........ ........ ........ ........ ........
02645 ; .####### ..##.... .####... .####... .##..... .####... .####... .#####..
02646 ; .#...### ...#.... ....#... ....#... .##..... .#...... .#..#... .#...#..
02647 ; .#...### ...#.... ....#... ....#... .##..... .#...... .#...... .....#..
02648 ; .#...### ...#.... .####... .#####.. .##.##.. .####... .#...... ...###..
02649 ; .#...### ..###... .#...... ....##.. .#####.. ....#... .######. ...#....
02650 ; .#...### ..###... .#...... ....##.. ....##.. ....#... .#....#. ...#....
02651 ; .####### ..###... .####... .#####.. ....##.. .####... .######. ...#....
02652 ;
02653 ; 8 9 10 11 12 13 14 15
02654 ; ........ ........ ........ ..###... #....... ........ ........ ........
02655 ; ..###... .#####.. ........ ..###... #....... ..####.. .##..##. ........
02656 ; ..#.#... .#...#.. ........ ..###... #....... ..#..... #..##..# ........
02657 ; ..#.#... .#...#.. ........ ........ #....... ..#..... #..##..# .######.
02658 ; .#####.. .#####.. ........ ........ #....... .####... #..##..# ........
02659 ; .##.##.. ....##.. ........ ..###... #....... .##..... .##..##. ........
02660 ; .##.##.. ....##.. ........ ..###... #....... .##..... ........ ........
02661 ; .#####.. ....##.. ........ ..###... ######## .#####.. ........ ........
02662 ;
02663 ; 16 17 18 19 20 21 22 23
02664 ; ........ ........ .##..##. ........ ........ ........ #######. ######..
02665 ; ...##... ...##... .##..##. .#####.. ...###.. .#...##. #..#..#. #...##..
02666 ; ...##... .######. .##..##. .#...#.. ..#####. .#...##. ...#.... #...##..
02667 ; ...##... ##.##.## .##..##. .#...#.. .##...## .#...#.. ...##... #.......
02668 ; .######. #..##..# .##..##. .#####.. .#.###.# .#####.. ...##... #.......
02669 ; ...##... ##.##.## ..#.##.. .##.#... .##...## .##..#.. ...##... #.......
02670 ; ...##... .######. ..###... .##.##.. ..#####. .##..##. ...##... #....#..
02671 ; ...##... ...##... ..##.... .##.##.. ...###.. .##..##. ...##... ######..
02672 ;
02673 ; 24 25 26 27 28 29 30
02674 ; ........ #....... ........ #....... #....... #....... #.......
02675 ; ........ #....... ........ #.#.#.#. #..##... #...###. #.##....
02676 ; ........ #....... ........ #..###.. #....... #....... #..##...
02677 ; ........ #....... ........ #.#####. #.##.##. #.###... #.#####.
02678 ; ........ #....... ........ #..###.. #....... #....... #..##...
02679 ; ........ #....... ........ #.#.#.#. #...##.. #..###.. #.##....
02680 ; ........ #....... ........ #....... #....... #....... #.......
02681 ; ######## #....... #....... ######## ######## ######## ########
02682
A000 007F4747 02683 CHARSET .BYTE $00,$7F,$47,$47,$47,$47,$47,$7F ; Custom character '0'
A004 4747477F
A008 00301010 02684 .BYTE $00,$30,$10,$10,$10,$38,$38,$38 ; Custom character '1'
A00C 10383838
A010 00780808 02685 .BYTE $00,$78,$08,$08,$78,$40,$40,$78 ; Custom character '2'
A014 78404078
A018 00780808 02686 .BYTE $00,$78,$08,$08,$7C,$0C,$0C,$7C ; Custom character '3'
A01C 7C0C0C7C
A020 00606060 02687 .BYTE $00,$60,$60,$60,$6C,$7C,$0C,$0C ; Custom character '4'
A024 6C7C0C0C
A028 00784040 02688 .BYTE $00,$78,$40,$40,$78,$08,$08,$78 ; Custom character '5'
A02C 78080878
A030 00784840 02689 .BYTE $00,$78,$48,$40,$40,$7E,$42,$7E ; Custom character '6'
A034 407E427E
A038 007C4404 02690 .BYTE $00,$7C,$44,$04,$1C,$10,$10,$10 ; Custom character '7'
A03C 1C101010
A040 00382828 02691 .BYTE $00,$38,$28,$28,$7C,$6C,$6C,$7C ; Custom character '8'
A044 7C6C6C7C
A048 007C4444 02692 .BYTE $00,$7C,$44,$44,$7C,$0C,$0C,$0C ; Custom character '9'
A04C 7C0C0C0C
A050 00000000 02693 .BYTE $00,$00,$00,$00,$00,$00,$00,$00 ; Custom character ' '
A054 00000000
A058 38383800 02694 .BYTE $38,$38,$38,$00,$00,$38,$38,$38 ; Custom character ':'
A05C 00383838
A060 80808080 02695 .BYTE $80,$80,$80,$80,$80,$80,$80,$FF ; Custom character 'BORDER SOUTHWEST'
A064 808080FF
A068 003C2020 02696 .BYTE $00,$3C,$20,$20,$78,$60,$60,$7C ; Custom character 'E'
A06C 7860607C
A070 00669999 02697 .BYTE $00,$66,$99,$99,$99,$66,$00,$00 ; Custom character 'INFINITY'
A074 99660000
A078 0000007E 02698 .BYTE $00,$00,$00,$7E,$00,$00,$00,$00 ; Custom character '-'
A07C 00000000
A080 00181818 02699 .BYTE $00,$18,$18,$18,$7E,$18,$18,$18 ; Custom character '+'
A084 7E181818
A088 00187EDB 02700 .BYTE $00,$18,$7E,$DB,$99,$DB,$7E,$18 ; Custom character 'PHI'
A08C 99DB7E18
A090 66666666 02701 .BYTE $66,$66,$66,$66,$66,$2C,$38,$30 ; Custom character 'V'
A094 662C3830
A098 007C4444 02702 .BYTE $00,$7C,$44,$44,$7C,$68,$6C,$6C ; Custom character 'R'
A09C 7C686C6C
A0A0 001C3E63 02703 .BYTE $00,$1C,$3E,$63,$5D,$63,$3E,$1C ; Custom character 'THETA'
A0A4 5D633E1C
A0A8 00464644 02704 .BYTE $00,$46,$46,$44,$7C,$64,$66,$66 ; Custom character 'K'
A0AC 7C646666
A0B0 FE921018 02705 .BYTE $FE,$92,$10,$18,$18,$18,$18,$18 ; Custom character 'T'
A0B4 18181818
A0B8 FC8C8C80 02706 .BYTE $FC,$8C,$8C,$80,$80,$80,$84,$FC ; Custom character 'C'
A0BC 808084FC
A0C0 00000000 02707 .BYTE $00,$00,$00,$00,$00,$00,$00,$FF ; Custom character 'BORDER SOUTH'
A0C4 000000FF
A0C8 80808080 02708 .BYTE $80,$80,$80,$80,$80,$80,$80,$80 ; Custom character 'BORDER WEST'
A0CC 80808080
A0D0 00000000 02709 .BYTE $00,$00,$00,$00,$00,$00,$00,$80 ; Custom character 'CORNER SOUTHWEST'
A0D4 00000080
A0D8 80AA9CBE 02710 .BYTE $80,$AA,$9C,$BE,$9C,$AA,$80,$FF ; Custom character 'STARBASE SECTOR'
A0DC 9CAA80FF
A0E0 809880B6 02711 .BYTE $80,$98,$80,$B6,$80,$8C,$80,$FF ; Custom character '4-ZYLON SECTOR'
A0E4 808C80FF
A0E8 808E80B8 02712 .BYTE $80,$8E,$80,$B8,$80,$9C,$80,$FF ; Custom character '3-CYCLON SECTOR'
A0EC 809C80FF
A0F0 80B098BE 02713 .BYTE $80,$B0,$98,$BE,$98,$B0,$80,$FF ; Custom character '2-ZYLON SECTOR'
A0F4 98B080FF
02714
02715 ;*** Header text of Long-Range Scan view (shares spaces with following header) *
A0F8 00006C6F 02716 LRSHEADER .BYTE $00,$00,$6C,$6F,$6E,$67,$00,$72 ; " LONG RANGE SCAN"
A0FC 6E670072
A100 616E6765 02717 .BYTE $61,$6E,$67,$65,$00,$73,$63,$61
A104 00736361
A108 6E 02718 .BYTE $6E
02719
02720 ;*** Header text of Aft view (shares spaces with following header) *************
A109 00000000 02721 AFTHEADER .BYTE $00,$00,$00,$00,$00,$00,$61,$66 ; " AFT VIEW "
A10D 00006166
A111 74007669 02722 .BYTE $74,$00,$76,$69,$65,$77,$00,$00
A115 65770000
A119 00 02723 .BYTE $00
02724
02725 ;*** Header text of Galactic Chart view ****************************************
A11A 00000067 02726 GCHEADER .BYTE $00,$00,$00,$67,$61,$6C,$61,$63 ; " GALACTIC CHART "
A11E 616C6163
A122 74696300 02727 .BYTE $74,$69,$63,$00,$63,$68,$61,$72
A126 63686172
A12A 74000000 02728 .BYTE $74,$00,$00,$00
02729
02730 ;*** Display List of Galactic Chart view ***************************************
A12E 60 02731 DLSTGC .BYTE $60 ; BLK7
A12F 461AA1 02732 .BYTE $46,<GCHEADER,>GCHEADER ; GR1 @ GCHEADER
A132 F0 02733 .BYTE $F0 ; BLK8 + DLI
A133 47350D 02734 .BYTE $47,<GCPFMEM,>GCPFMEM ; GR2 @ GCPFMEM
A136 07 02735 .BYTE $07 ; GR2
A137 07 02736 .BYTE $07 ; GR2
A138 07 02737 .BYTE $07 ; GR2
A139 07 02738 .BYTE $07 ; GR2
A13A 07 02739 .BYTE $07 ; GR2
A13B 07 02740 .BYTE $07 ; GR2
A13C 07 02741 .BYTE $07 ; GR2
A13D 07 02742 .BYTE $07 ; GR2
A13E 80 02743 .BYTE $80 ; BLK1 + DLI
A13F 461F0D 02744 .BYTE $46,<TITLETXT,>TITLETXT ; GR1 @ TITLETXT
A142 467109 02745 .BYTE $46,<GCTXT,>GCTXT ; GR1 @ GCTXT
A145 06 02746 .BYTE $06 ; GR1
A146 06 02747 .BYTE $06 ; GR1
A147 418002 02748 .BYTE $41,<DSPLST,>DSPLST ; JMP @ DSPLST
02749
02750 ;*******************************************************************************
02751 ;* *
02752 ;* G A M E C O D E *
02753 ;* *
02754 ;*******************************************************************************
02755
02756 ;*******************************************************************************
02757 ;* *
02758 ;* INITCOLD *
02759 ;* *
02760 ;* Initialize game (Cold start) *
02761 ;* *
02762 ;*******************************************************************************
02763
02764 ; DESCRIPTION
02765 ;
02766 ; Initializes the game, then continues into the game loop at GAMELOOP ($A1F3).
02767 ;
02768 ; There are four entry points to initialization:
02769 ;
02770 ; (1) INITCOLD ($A14A) is entered at initial cartridge startup (cold start).
02771 ; This initializes POKEY, resets the idle counter, sets the mission level
02772 ; to NOVICE mission, and clears the function key code. POKEY is enabled to
02773 ; receive keyboard input. Code execution continues into INITSELECT ($A15A)
02774 ; below.
02775 ;
02776 ; (2) INITSELECT ($A15A) is entered from GAMELOOP ($A1F3) after the SELECT
02777 ; function key has been pressed. This loads the title phrase offset for the
02778 ; copyright notice. Code execution continues into INITDEMO ($A15C) below.
02779 ;
02780 ; (3) INITDEMO ($A15C) is entered when the game switches into demo mode. This
02781 ; loads the demo mode flag. Code execution continues into INITSTART ($A15E)
02782 ; below.
02783 ;
02784 ; (4) INITSTART ($A15E) is entered from GAMELOOP ($A1F3) after the START
02785 ; function key has been pressed. This enqueues the new title phrase and
02786 ; enables or disables demo mode, depending on the preloaded value.
02787 ;
02788 ; Initialization continues with the following steps:
02789 ;
02790 ; (1) Clear the custom chip registers and zero page game variables from
02791 ; ISVBISYNC ($0067) on.
02792 ;
02793 ; NOTE: Because of loop jamming there is a loop index overshoot. This
02794 ; clears memory at $0067..$0166 instead of the game's zero page memory at
02795 ; $0067..$00FB. However, this does no harm because memory at $0100..$0166
02796 ; is - at this point in time - a yet unused part of the 6502 CPU stack
02797 ; (memory addresses $0100..$01FF).
02798 ;
02799 ; NOTE: At address $A175 a hack is necessary in the source code to force an
02800 ; STA ISVBISYNC,X instruction with a 16-bit address operand, as opposed to
02801 ; an 8-bit (zero page) address operand. The latter would be chosen by
02802 ; virtually all 6502 assemblers, as ISVBISYNC ($0067) is located in the
02803 ; zero page (memory addresses $0000..$00FF). The reason to force a 16-bit
02804 ; address operand is the following: The instruction STA ISVBISYNC,X is used
02805 ; in a loop which iterates the CPU's X register from 0 to 255 to clear
02806 ; memory. By using this instruction with a 16-bit address operand
02807 ; ("indexed, absolute" mode), memory at $0067..$0166 is cleared. Had the
02808 ; code been using the same operation with an 8-bit address operand
02809 ; ("indexed, zero page" mode), memory at $0067..$00FF would have been
02810 ; cleared first, then the indexed address would have wrapped back to $0000
02811 ; and cleared memory at $0000..$0066, thus effectively overwriting already
02812 ; initialized memory locations.
02813 ;
02814 ; (2) Initialize the 6502 CPU (reset the stack pointer, disable decimal mode).
02815 ;
02816 ; (3) Clear game memory from $0200..$1FFF in subroutine CLRMEM ($AE0F).
02817 ;
02818 ; (4) Set the address vectors of the IRQ, VBI, and DLI handlers.
02819 ;
02820 ; (5) Enable input from Joystick 0.
02821 ;
02822 ; (6) Enable Player/Missile graphics, providing a fifth PLAYER, and set
02823 ; PLAYER-PLAYFIELD priority.
02824 ;
02825 ; BUG (at $A1A6): The set PLAYER-PLAYFIELD priority arranges PLAYERs
02826 ; (PL0..4) in front of the PLAYFIELD (PF0..4) in this specific order, from
02827 ; front to back:
02828 ;
02829 ; PL0 > PL1 > PL2 > PL3 > PL4 > PF0, PF1, PF2 > PF4 (BGR)
02830 ;
02831 ; This makes sense as space objects represented by PLAYERs (for example,
02832 ; Zylon ships, photon torpedoes, and meteors) move in front of the stars,
02833 ; which are part of the PLAYFIELD. However, PLAYERs also move in front of
02834 ; the cross hairs, which are also part of the PLAYFIELD. Suggested fix:
02835 ; None, technically not possible.
02836 ;
02837 ; (7) Do more initialization in subroutine INITIALIZE ($B3BA).
02838 ;
02839 ; (8) Set display to Front view.
02840 ;
02841 ; (9) Show or hide the Control Panel Display (bottom text window) in subroutine
02842 ; MODDLST ($ADF1), depending on the demo mode flag.
02843 ;
02844 ; (10) Initialize our starship's velocity equivalent to speed key '6'.
02845 ;
02846 ; (11) Enable the Display List.
02847 ;
02848 ; (12) Initialize the number of space objects to 16 (5 PLAYER space objects + 12
02849 ; PLAYFIELD space objects (stars), counted 0..16).
02850 ;
02851 ; (13) Set the title phrase to the selected mission level in subroutine SETTITLE
02852 ; ($B223).
02853 ;
02854 ; (14) Enable the IRQ, DLI, and VBI interrupts.
02855 ;
02856 ; Code execution continues into the game loop at GAMELOOP ($A1F3).
02857
A14A A900 02858 INITCOLD LDA #0 ;
A14C 8D0FD2 02859 STA SKCTL ; POKEY: Initialization
A14F 8566 02860 STA IDLECNTHI ; Reset idle counter
A151 8562 02861 STA MISSIONLEVEL ; Mission level := NOVICE mission
A153 8563 02862 STA FKEYCODE ; Clear function key code
A155 A903 02863 LDA #$03 ; POKEY: Enable keyboard scan and debounce
A157 8D0FD2 02864 STA SKCTL ;
02865
02866 ;*** Entry point when SELECT function key was pressed **************************
A15A A02F 02867 INITSELECT LDY #$2F ; Prep title phrase "COPYRIGHT ATARI 1979"
02868
02869 ;*** Entry point when game switches into demo mode *****************************
A15C A9FF 02870 INITDEMO LDA #$FF ; Prep demo mode flag
02871
02872 ;*** Entry point when START function key was pressed ***************************
A15E 8465 02873 INITSTART STY NEWTITLEPHR ; Enqueue new title phrase
A160 8564 02874 STA ISDEMOMODE ; Store demo mode flag
02875
02876 ;*** More initialization *******************************************************
A162 A900 02877 LDA #0 ; Clear custom chip registers, zero page variables
A164 AA 02878 TAX ;
A165 9D00D0 02879 LOOP001 STA HPOSP0,X ; Clear $D000..$D0FF (GTIA registers)
A168 9D00D4 02880 STA DMACTL,X ; Clear $D400..$D4FF (ANTIC registers)
A16B E00F 02881 CPX #$0F ;
A16D B003 02882 BCS SKIP001 ;
A16F 9D00D2 02883 STA AUDF1,X ; Clear $D200..$D20E (POKEY registers)
02884
A172 9D00D3 02885 SKIP001 STA PORTA,X ; Clear $D300..$D3FF (PIA registers)
02886 ; Clear $0067..$0166 (zero page game variables)
A175 9D 02887 .BYTE $9D ; HACK: Force ISVBISYNC,X with 16-bit address
A176 6700 02888 .WORD ISVBISYNC ; (loop jamming)
A178 E8 02889 INX ;
A179 D0EA 02890 BNE LOOP001 ;
02891
A17B CA 02892 DEX ; Reset 6502 CPU stack pointer
A17C 9A 02893 TXS ;
02894
A17D D8 02895 CLD ; Clear 6502 CPU decimal mode
02896
A17E A902 02897 LDA #$02 ; Clear $0200..$1FFF (game memory)
A180 200FAE 02898 JSR CLRMEM ;
02899
A183 A951 02900 LDA #<IRQHNDLR ; Set IRQ handler (VIMIRQ)
A185 8D1602 02901 STA VIMIRQ ;
A188 A9A7 02902 LDA #>IRQHNDLR ;
A18A 8D1702 02903 STA VIMIRQ+1 ;
02904
A18D A9D1 02905 LDA #<VBIHNDLR ; Set VBI and DLI handler (VVBLKI and VDSLST)
A18F 8D2202 02906 STA VVBLKI ;
A192 A918 02907 LDA #<DLSTHNDLR ;
A194 8D0002 02908 STA VDSLST ;
A197 A9A6 02909 LDA #>VBIHNDLR ;
A199 8D2302 02910 STA VVBLKI+1 ;
A19C A9A7 02911 LDA #>DLSTHNDLR ;
A19E 8D0102 02912 STA VDSLST+1 ;
02913
A1A1 A904 02914 LDA #$04 ; PIA: Enable PORTA (Joystick 0)
A1A3 8D02D3 02915 STA PACTL ;
A1A6 A911 02916 LDA #$11 ; GTIA: Enable PLAYER4, prio: PLs > PFs > BGR (!)
A1A8 8D1BD0 02917 STA PRIOR ; (PLAYERs in front of stars - and cross hairs)
A1AB A903 02918 LDA #$03 ; GTIA: Enable DMA for PLAYERs and MISSILEs
A1AD 8D1DD0 02919 STA GRACTL ;
02920
A1B0 20BAB3 02921 JSR INITIALIZE ; Init Display List, tables, Galactic Chart, etc.
02922
A1B3 A20A 02923 LDX #$0A ; Set Front view
A1B5 2045B0 02924 JSR SETVIEW ;
02925
A1B8 A564 02926 LDA ISDEMOMODE ; If in/not in demo mode hide/show...
A1BA 2980 02927 AND #$80 ; ...Control Panel Display (bottom text window)
A1BC A8 02928 TAY ;
A1BD A25F 02929 LDX #$5F ;
A1BF A908 02930 LDA #$08 ;
A1C1 20F1AD 02931 JSR MODDLST ;
02932
A1C4 A920 02933 LDA #32 ; Init our starship's velocity (= speed key '6')
A1C6 8571 02934 STA NEWVELOCITY ;
02935
A1C8 A980 02936 LDA #<DSPLST ; ANTIC: Set Display List
A1CA 8D02D4 02937 STA DLIST ;
A1CD A902 02938 LDA #>DSPLST ;
A1CF 8D03D4 02939 STA DLIST+1 ;
02940
A1D2 A93E 02941 LDA #$3E ; ANTIC: Enable Display List DMA, single-line PM
A1D4 8D00D4 02942 STA DMACTL ; resolution, PM DMA, normal-width PLAYFIELD
02943
A1D7 A900 02944 LDA #0 ; ANTIC: Set PM memory base address
A1D9 8D07D4 02945 STA PMBASE ;
02946
A1DC A910 02947 LDA #NUMSPCOBJ.NORM-1 ; Set normal number of space objects
A1DE 8579 02948 STA MAXSPCOBJIND ; (5 PLAYER spc objs + 12 PLAYFIELD spc objs (stars))
02949
A1E0 A662 02950 LDX MISSIONLEVEL ; Set title phrase
A1E2 BC0CBF 02951 LDY MISSIONPHRTAB,X ; NOVICE, PILOT, WARRIOR, or COMMANDER MISSION
A1E5 2023B2 02952 JSR SETTITLE ;
02953
A1E8 A940 02954 LDA #$40 ; POKEY: Enable keyboard interrupt (IRQ)
A1EA 8D0ED2 02955 STA IRQEN ;
02956
A1ED 58 02957 CLI ; Enable all IRQs
02958
A1EE A9C0 02959 LDA #$C0 ; ANTIC: Enable DLI and VBI
A1F0 8D0ED4 02960 STA NMIEN ;
02961
02962 ;*******************************************************************************
02963 ;* *
02964 ;* GAMELOOP *
02965 ;* *
02966 ;*******************************************************************************
02967
02968 ; DESCRIPTION
02969 ;
02970 ; The game loop is the main part of the game. It is basically an infinite loop
02971 ; that collects input, computes the game state, and updates the display. It
02972 ; executes the following steps:
02973 ;
02974 ; (1) Synchronize the start of the game loop with the vertical blank phase of
02975 ; the TV beam, which flagged by the Vertical Blank Interrupt handler
02976 ; VBIHNDLR ($A6D1). This prevents screen flicker while the PLAYFIELD is
02977 ; redrawn at the beginning of the game loop, because during the vertical
02978 ; blank phase the TV beam is turned off and nothing is rendered on the TV
02979 ; display.
02980 ;
02981 ; (2) Erase all PLAYFIELD space objects (stars, explosion fragments) from the
02982 ; PLAYFIELD that were drawn in the previous game loop iteration.
02983 ;
02984 ; (3) Draw the updated PLAYFIELD space objects (stars, explosion fragments)
02985 ; into the PLAYFIELD (skip this if in hyperspace).
02986 ;
02987 ; (4) If the idle counter has reached its trigger value then clear the center
02988 ; of the PLAYFIELD, an 8 x 2 pixel rectangle with a top-left position at
02989 ; pixel column number 76 and pixel row number 49 (?).
02990 ;
02991 ; (5) Clear all PLAYER shapes.
02992 ;
02993 ; (6) Update the vertical position of all PLAYERs and update all PLAYER shapes.
02994 ;
02995 ; (7) Update the horizontal position of all PLAYERs.
02996 ;
02997 ; (8) Rotate the position vector of all space objects horizontally and
02998 ; vertically, according to the saved joystick position (skip this if in
02999 ; Galactic Chart view) using subroutine ROTATE ($B69B).
03000 ;
03001 ; (9) Move our starship forward in space. Our starship is always located at the
03002 ; center of the game's 3D coordinate system, so all space objects are moved
03003 ; along the z-axis toward our starship by subtracting a displacement from
03004 ; their z-coordinate. The amount of the displacement depends on our
03005 ; starship's velocity.
03006 ;
03007 ; BUG (at $A3C1): This operation is not applied to Photon torpedoes (?).
03008 ; Suggested fix: Remove LDA PL0SHAPTYPE,X and BEQ SKIP011.
03009 ;
03010 ; (10) Add the proper velocity vector of all space objects to their position
03011 ; vector (except for stars, which do not have any proper motion).
03012 ;
03013 ; BUG (at $A419): The correct maximum loop index is NUMSPCOBJ.ALL*3 = 147
03014 ; instead of 144. Suggested fix: Replace CMP #144 with CMP #147.
03015 ;
03016 ; (11) Correct the position vector components (coordinates) of all PLAYER space
03017 ; objects if they have over- or underflowed during the calculations of the
03018 ; previous steps.
03019 ;
03020 ; (12) Calculate the perspective projection of the position vectors of all space
03021 ; objects and from that their pixel row and column number (applies to Front
03022 ; and Aft view) using subroutines PROJECTION ($AA21), SCREENCOLUMN ($B6FB),
03023 ; and SCREENROW ($B71E). If a space object (star, explosion fragment) moved
03024 ; offscreen then a new space object is automatically created in subroutine
03025 ; SCREENCOLUMN ($B6FB).
03026 ;
03027 ; (13) Handle hyperwarp marker selection in the Galactic Chart view in
03028 ; subroutine SELECTWARP ($B162).
03029 ;
03030 ; (14) If in Long-Range Scan view, compute the pixel column number and the pixel
03031 ; row number of all PLAYFIELD space objects (stars, explosion fragments) on
03032 ; the plane established by the z and x axis of the 3D coordinate system
03033 ; using subroutines SCREENCOLUMN ($B6FB) and SCREENROW ($B71E). Our
03034 ; starship's shape is drawn using subroutine DRAWLINES ($A76F). If the
03035 ; Long-Range Scan is OK then PLAYFIELD space object pixel numbers are
03036 ; computed and drawn. This is skipped if the Long-Range Scan is destroyed.
03037 ;
03038 ; (15) Update all PLAYER shapes, heights, and colors (see detailed description
03039 ; below).
03040 ;
03041 ; (16) Flash a red alert when leaving hyperspace into a sector containing Zylon
03042 ; ships by setting appropriate colors to PLAYFIELD2 and BACKGROUND.
03043 ;
03044 ; (17) Update the color of all PLAYFIELD space objects (stars, explosion
03045 ; fragments). The color calculation is similar to that of the PLAYER color
03046 ; calculation in (15). It also computes a range index and uses the same
03047 ; color lookup table FOURCOLORPIXEL ($BA90). If a star in the Aft view
03048 ; became too distant (z-coordinate < -$F000 (-4096) <KM>) its position is
03049 ; re-initialized in subroutine INITPOSVEC ($B764).
03050 ;
03051 ; (18) If in demo mode skip input handling and jump directly to function key
03052 ; handling (28).
03053 ;
03054 ; (19) Handle keyboard input in subroutine KEYBOARD ($AFFE).
03055 ;
03056 ; (20) Handle joystick input. Store the current joystick directions in JOYSTICKX
03057 ; ($C8) and JOYSTICKY ($C9).
03058 ;
03059 ; (21) Check if our starship's photon torpedoes have hit a target in subroutine
03060 ; COLLISION ($AF3D). This subroutine triggers a game over if all Zylon
03061 ; ships have been destroyed.
03062 ;
03063 ; (22) Handle the joystick trigger in subroutine TRIGGER ($AE29).
03064 ;
03065 ; (23) Handle the Attack Computer and Tracking Computer. If the Attack Computer
03066 ; is neither destroyed nor switched off then execute the following steps:
03067 ;
03068 ; o Update the Attack Computer Display's blip and lock-on markers in
03069 ; subroutine UPDATTCOMP ($A7BF) (if in Front view).
03070 ;
03071 ; o Update the tracking index of the currently tracked PLAYER space
03072 ; object. If a Zylon ship is tracked, then make sure to always track
03073 ; the Zylon ship that launched the last Zylon photon torpedo. If this
03074 ; Zylon ship is not alive then track the other Zylon ship - if alive.
03075 ;
03076 ; o If the Tracking Computer is on then switch to the view that shows the
03077 ; tracked PLAYER space object by emulating pressing the 'F' (Front
03078 ; view) or 'A' (Aft view) key (only if in Front or Aft view).
03079 ;
03080 ; (24) Handle docking at a starbase in subroutine DOCKING ($ACE6).
03081 ;
03082 ; (25) Handle maneuvering both of our starship's photon torpedoes, the single
03083 ; Zylon photon torpedo, and the attacking Zylon ships in subroutine
03084 ; MANEUVER ($AA79). This subroutine also automatically creates meteors and
03085 ; new Zylon ships.
03086 ;
03087 ; (26) Check if our starship was hit by a Zylon photon torpedo (skip this if in
03088 ; a starbase sector): Its x, y, and z coordinates must be within a range of
03089 ; -($0100)..+$00FF (-256..+255) <KM> of our starship.
03090 ;
03091 ; (27) If our starship was hit then execute the following steps:
03092 ;
03093 ; o Damage or destroy one of our starship's subsystems in subroutine
03094 ; DAMAGE ($AEE1).
03095 ;
03096 ; o Trigger an explosion in subroutine INITEXPL ($AC6B),
03097 ;
03098 ; o Store the severity of the hit.
03099 ;
03100 ; o End the lifetime of the Zylon photon torpedo.
03101 ;
03102 ; o Subtract 100 energy units for being hit by the Zylon photon torpedo
03103 ; in subroutine DECENERGY ($B86F).
03104 ;
03105 ; o Trigger the noise sound pattern SHIELD EXPLOSION in subroutine NOISE
03106 ; ($AEA8).
03107 ;
03108 ; If the Shields were down during the hit, our starship is destroyed.
03109 ; Execute the following steps:
03110 ;
03111 ; o Switch to Front view.
03112 ;
03113 ; o Flash the title phrase "SHIP DESTROYED BY ZYLON FIRE".
03114 ;
03115 ; o Add the mission bonus to the internal game score in subroutine
03116 ; GAMEOVER ($B10A).
03117 ;
03118 ; o Hide the Control Panel Display (bottom text window) in subroutine
03119 ; MODDLST ($ADF1).
03120 ;
03121 ; o Clear the PLAYFIELD in subroutine CLRPLAYFIELD ($AE0D).
03122 ;
03123 ; o Enable the STARSHIP EXPLOSION noise.
03124 ;
03125 ; (28) Handle the function keys START and SELECT. If SELECT has been pressed
03126 ; cycle through the next of the 4 mission levels. If either START or SELECT
03127 ; have been pressed, reset the idle counter, then jump to the corresponding
03128 ; game initialization subroutines INITSTART ($A15E) or INITSELECT ($A15A),
03129 ; respectively.
03130 ;
03131 ; (29) Update the Control Panel Display in subroutine UPDPANEL ($B804).
03132 ;
03133 ; (30) Handle hyperwarp in subroutine HYPERWARP ($A89B).
03134 ;
03135 ; (31) Update the text in the title line in subroutine UPDTITLE ($B216).
03136 ;
03137 ; (32) Move Zylon units, decrease lifetime of photon torpedoes, elapse game
03138 ; time, etc. in subroutine FLUSHGAMELOOP ($B4E4). This subroutine also
03139 ; triggers a game over if our starship's energy is zero.
03140 ;
03141 ; (33) Jump back to the start of the game loop for the next game loop iteration.
03142
=006A 03143 L.HEIGHTCNT = $6A ; Height counter during copying a PLAYER shape
=006E 03144 L.ZPOSOFF = $6E ; Offset to z-coordinate
=006B 03145 L.VELOCITYHI = $6B ; Velocity vector component (high byte)
=006A 03146 L.VECCOMPIND = $6A ; Position vector component index. Used values are:
03147 ; 0 -> z-component
03148 ; 1 -> x-component
03149 ; 2 -> y-component
=006A 03150 L.RANGEINDEX = $6A ; Range index for space object, computed from the
03151 ; distance to our starship. Used to pick the shape
03152 ; cell index of the PLAYERs shape data and shape
03153 ; height. Used values are: 0..15.
=006A 03154 L.FOURCOLORPIX = $6A ; 1-byte bit pattern for 4 pixels of same color
=006B 03155 L.COLORMASK = $6B ; Color/brightness to modify PLAYER color
03156
03157 ;*** (1) Synchronize game loop with execution of VBI ***************************
A1F3 A567 03158 GAMELOOP LDA ISVBISYNC ; Wait for execution of VBI
A1F5 F0FC 03159 BEQ GAMELOOP ;
03160
A1F7 A900 03161 LDA #0 ; VBI is executed, clear VBI sync flag
A1F9 8567 03162 STA ISVBISYNC ;
03163
03164 ;*** (2) Erase PLAYFIELD space objects (stars, explosion fragments) ************
A1FB A57A 03165 LDA OLDMAXSPCOBJIND ; Skip if no space objects in use
A1FD F020 03166 BEQ SKIP002 ;
03167
A1FF A204 03168 LDX #NUMSPCOBJ.PL-1 ; Loop over all PLAYFIELD space objs (X index > 4)
A201 E8 03169 LOOP002 INX ;
A202 BC5B0C 03170 LDY PIXELROW,X ; Load pixel row number of PLAYFIELD space object
03171
A205 B90008 03172 LDA PFMEMROWLO,Y ; Point MEMPTR to start of pixel's row...
A208 8568 03173 STA MEMPTR ; ...in PLAYFIELD memory
A20A B96408 03174 LDA PFMEMROWHI,Y ;
A20D 8569 03175 STA MEMPTR+1 ;
03176
A20F BC8C0C 03177 LDY PIXELBYTEOFF,X ; Get within-row-offset to byte with space obj pixel
A212 BDBD0C 03178 LDA PIXELSAVE,X ; Load saved byte
A215 9168 03179 STA (MEMPTR),Y ; Restore byte of PLAYFIELD memory
03180
A217 E47A 03181 CPX OLDMAXSPCOBJIND ;
A219 90E6 03182 BCC LOOP002 ; Next PLAYFIELD space object
03183
A21B A900 03184 LDA #0 ; Clear number of space objects
A21D 857A 03185 STA OLDMAXSPCOBJIND ;
03186
03187 ;*** (3) Draw PLAYFIELD space objects (stars, explosion fragments) *************
A21F A5C0 03188 SKIP002 LDA WARPSTATE ; Skip during hyperspace
A221 302D 03189 BMI SKIP003 ;
03190
A223 A679 03191 LDX MAXSPCOBJIND ; Update number of space objects
A225 867A 03192 STX OLDMAXSPCOBJIND ;
03193
A227 BDF90B 03194 LOOP003 LDA PIXELROWNEW,X ; Loop over all PLAYFIELD space objs (X index > 4)
A22A 9D5B0C 03195 STA PIXELROW,X ; Update pixel row number of PLAYFIELD space object
03196
A22D A8 03197 TAY ;
A22E B90008 03198 LDA PFMEMROWLO,Y ; Point MEMPTR to start of pixel's row...
A231 8568 03199 STA MEMPTR ; ...in PLAYFIELD memory
A233 B96408 03200 LDA PFMEMROWHI,Y ;
A236 8569 03201 STA MEMPTR+1 ;
03202
A238 BD2A0C 03203 LDA PIXELCOLUMN,X ; Convert pixel column number to within-row-offset
A23B 4A 03204 LSR A ; ...of byte with space obj pixel (4 pixels = 1 byte)
A23C 4A 03205 LSR A ;
A23D 9D8C0C 03206 STA PIXELBYTEOFF,X ; Store within-row-offset
03207
A240 A8 03208 TAY ;
A241 B168 03209 LDA (MEMPTR),Y ; Load pixel's byte from PLAYFIELD memory
A243 9DBD0C 03210 STA PIXELSAVE,X ; Save it (for restoring it in next game loop)
A246 1DEE0C 03211 ORA PIXELBYTE,X ; Blend with pixel's color bit-pattern
A249 9168 03212 STA (MEMPTR),Y ; Store byte in PLAYFIELD memory
03213
A24B CA 03214 DEX ;
A24C E004 03215 CPX #NUMSPCOBJ.PL-1 ;
A24E D0D7 03216 BNE LOOP003 ; Next PLAYFIELD space object
03217
03218 ;*** (4) Clear PLAYFIELD center if idle counter is up (?) **********************
03219 ; PLAYFIELD addresses of...
=17BB 03220 PFMEM.C76R49 = PFMEM+49*40+76/4 ; ...pixel column number 76, row number 49
=17BC 03221 PFMEM.C80R49 = PFMEM+49*40+80/4 ; ...pixel column number 80, row number 49
=17E3 03222 PFMEM.C76R50 = PFMEM+50*40+76/4 ; ...pixel column number 76, row number 50
=17E4 03223 PFMEM.C80R50 = PFMEM+50*40+80/4 ; ...pixel column number 80, row number 50
03224
A250 A566 03225 SKIP003 LDA IDLECNTHI ; Skip if idle counter not negative
A252 100E 03226 BPL SKIP004 ;
03227
A254 A900 03228 LDA #0 ; Clear pixels of 8 x 2 pixel rectangle...
A256 8DE317 03229 STA PFMEM.C76R50 ; ...@ column number 76, row number 49 (?)
A259 8DE417 03230 STA PFMEM.C80R50 ;
A25C 8DBC17 03231 STA PFMEM.C80R49 ;
A25F 8DBB17 03232 STA PFMEM.C76R49 ;
03233
03234 ;*** (5) Clear all PLAYER shapes ***********************************************
A262 A900 03235 SKIP004 LDA #0 ; Clear shape of PLAYER4
A264 AC5F0C 03236 LDY PL4ROW ;
A267 AEC10C 03237 LDX PL4HEIGHT ;
A26A 990003 03238 LOOP004 STA PL4DATA,Y ;
A26D C8 03239 INY ;
A26E CA 03240 DEX ;
A26F 10F9 03241 BPL LOOP004 ;
03242
A271 AC5E0C 03243 LDY PL3ROW ; Clear shape of PLAYER3
A274 AEC00C 03244 LDX PL3HEIGHT ;
A277 990007 03245 LOOP005 STA PL3DATA,Y ;
A27A C8 03246 INY ;
A27B CA 03247 DEX ;
A27C 10F9 03248 BPL LOOP005 ;
03249
A27E AC5D0C 03250 LDY PL2ROW ; Clear shape of PLAYER2
A281 AEBF0C 03251 LDX PL2HEIGHT ;
A284 990006 03252 LOOP006 STA PL2DATA,Y ;
A287 C8 03253 INY ;
A288 CA 03254 DEX ;
A289 10F9 03255 BPL LOOP006 ;
03256
A28B AC5C0C 03257 LDY PL1ROW ; Clear shape of PLAYER1
A28E AEBE0C 03258 LDX PL1HEIGHT ;
A291 990005 03259 LOOP007 STA PL1DATA,Y ;
A294 C8 03260 INY ;
A295 CA 03261 DEX ;
A296 10F9 03262 BPL LOOP007 ;
03263
A298 AC5B0C 03264 LDY PL0ROW ; Clear shape of PLAYER0
A29B AEBD0C 03265 LDX PL0HEIGHT ;
A29E 990004 03266 LOOP008 STA PL0DATA,Y ;
A2A1 C8 03267 INY ;
A2A2 CA 03268 DEX ;
A2A3 10F9 03269 BPL LOOP008 ;
03270
03271 ;*** (6) Update PLAYER vertical positions and update PLAYER shapes *************
A2A5 AD900C 03272 LDA PL4SHAPTYPE ; CARRY := PLAYER4 a PHOTON TORPEDO (shape type 0)?
A2A8 C901 03273 CMP #1 ;
A2AA A4E8 03274 LDY PL4SHAPOFF ; Load PLAYER4 shape data offset
03275
A2AC AEFD0B 03276 LDX PL4ROWNEW ; Update vertical position of PLAYER4
A2AF 8E5F0C 03277 STX PL4ROW ;
03278
A2B2 ADF20C 03279 LDA PL4HEIGHTNEW ; Update PLAYER4 shape height
A2B5 856A 03280 STA L.HEIGHTCNT ;
A2B7 8DC10C 03281 STA PL4HEIGHT ;
03282
A2BA B9E4B8 03283 LOOP009 LDA PLSHAP1TAB,Y ; Load PLAYER4 shape byte from shape data table
A2BD B003 03284 BCS SKIP005 ; Skip if PLAYER4 not PHOTON TORPEDO (shape type 0)
A2BF 2D0AD2 03285 AND RANDOM ; AND random bits to shape byte
A2C2 9D0003 03286 SKIP005 STA PL4DATA,X ; Store shape byte in PLAYER4 data area
A2C5 C8 03287 INY ;
A2C6 E8 03288 INX ;
A2C7 C66A 03289 DEC L.HEIGHTCNT ;
A2C9 10EF 03290 BPL LOOP009 ; Next row of PLAYER4 shape
03291
A2CB AD8F0C 03292 LDA PL3SHAPTYPE ; Repeat above with PLAYER3
A2CE C901 03293 CMP #1 ;
A2D0 A4E7 03294 LDY PL3SHAPOFF ;
A2D2 AEFC0B 03295 LDX PL3ROWNEW ;
A2D5 8E5E0C 03296 STX PL3ROW ;
A2D8 ADF10C 03297 LDA PL3HEIGHTNEW ;
A2DB 856A 03298 STA L.HEIGHTCNT ;
A2DD 8DC00C 03299 STA PL3HEIGHT ;
A2E0 B9E4B8 03300 LOOP010 LDA PLSHAP1TAB,Y ;
A2E3 B003 03301 BCS SKIP006 ;
A2E5 2D0AD2 03302 AND RANDOM ;
A2E8 9D0007 03303 SKIP006 STA PL3DATA,X ;
A2EB E8 03304 INX ;
A2EC C8 03305 INY ;
A2ED C66A 03306 DEC L.HEIGHTCNT ;
A2EF 10EF 03307 BPL LOOP010 ;
03308
A2F1 AD8E0C 03309 LDA PL2SHAPTYPE ; Repeat above with PLAYER2
A2F4 C901 03310 CMP #1 ;
A2F6 A4E6 03311 LDY PL2SHAPOFF ;
A2F8 AEFB0B 03312 LDX PL2ROWNEW ;
A2FB 8E5D0C 03313 STX PL2ROW ;
A2FE ADF00C 03314 LDA PL2HEIGHTNEW ;
A301 856A 03315 STA L.HEIGHTCNT ;
A303 8DBF0C 03316 STA PL2HEIGHT ;
A306 B9E4B8 03317 LOOP011 LDA PLSHAP1TAB,Y ;
A309 B003 03318 BCS SKIP007 ;
A30B 2D0AD2 03319 AND RANDOM ;
A30E 9D0006 03320 SKIP007 STA PL2DATA,X ;
A311 E8 03321 INX ;
A312 C8 03322 INY ;
A313 C66A 03323 DEC L.HEIGHTCNT ;
A315 10EF 03324 BPL LOOP011 ;
03325
A317 A4E5 03326 LDY PL1SHAPOFF ; Repeat above with PLAYER1 (without torpedo part)
A319 AEFA0B 03327 LDX PL1ROWNEW ;
A31C 8E5C0C 03328 STX PL1ROW ;
A31F ADEF0C 03329 LDA PL1HEIGHTNEW ;
A322 856A 03330 STA L.HEIGHTCNT ;
A324 8DBE0C 03331 STA PL1HEIGHT ;
A327 B9B1B9 03332 LOOP012 LDA PLSHAP2TAB,Y ;
A32A 9D0005 03333 STA PL1DATA,X ;
A32D E8 03334 INX ;
A32E C8 03335 INY ;
A32F C66A 03336 DEC L.HEIGHTCNT ;
A331 10F4 03337 BPL LOOP012 ;
03338
A333 A4E4 03339 LDY PL0SHAPOFF ; Repeat above with PLAYER0 (without torpedo part)
A335 AEF90B 03340 LDX PL0ROWNEW ;
A338 8E5B0C 03341 STX PL0ROW ;
A33B ADEE0C 03342 LDA PL0HEIGHTNEW ;
A33E 856A 03343 STA L.HEIGHTCNT ;
A340 8DBD0C 03344 STA PL0HEIGHT ;
A343 B9B1B9 03345 LOOP013 LDA PLSHAP2TAB,Y ;
A346 9D0004 03346 STA PL0DATA,X ;
A349 E8 03347 INX ;
A34A C8 03348 INY ;
A34B C66A 03349 DEC L.HEIGHTCNT ;
A34D 10F4 03350 BPL LOOP013 ;
03351
03352 ;*** (7) Update PLAYER horizontal positions ************************************
A34F AD2A0C 03353 LDA PL0COLUMN ; Update horizontal position of PLAYER0
A352 8D00D0 03354 STA HPOSP0 ;
A355 AD2B0C 03355 LDA PL1COLUMN ; Update horizontal position of PLAYER1
A358 8D01D0 03356 STA HPOSP1 ;
A35B AD2C0C 03357 LDA PL2COLUMN ; Update horizontal position of PLAYER2
A35E 8D02D0 03358 STA HPOSP2 ;
A361 AD2D0C 03359 LDA PL3COLUMN ; Update horizontal position of PLAYER3
A364 8D03D0 03360 STA HPOSP3 ;
A367 AD2E0C 03361 LDA PL4COLUMN ; Update horizontal position of PLAYER4
A36A 8D07D0 03362 STA HPOSM3 ;
A36D 18 03363 CLC ;
A36E 6902 03364 ADC #2 ;
A370 8D06D0 03365 STA HPOSM2 ;
A373 6902 03366 ADC #2 ;
A375 8D05D0 03367 STA HPOSM1 ;
A378 6902 03368 ADC #2 ;
A37A 8D04D0 03369 STA HPOSM0 ;
03370
03371 ;*** (8) Rotate space objects horizontally and vertically **********************
A37D 24D0 03372 BIT SHIPVIEW ; Skip if in Galactic Chart view
A37F 303A 03373 BMI SKIP009 ;
03374
03375 ;*** Rotate horizontally *******************************************************
A381 A5C8 03376 LDA JOYSTICKX ; Skip if joystick centered horizontally
A383 F019 03377 BEQ SKIP008 ;
03378
A385 856D 03379 STA JOYSTICKDELTA ; Save JOYSTICKX (used in subroutine ROTATE)
A387 A479 03380 LDY MAXSPCOBJIND ; Loop over all space objects in use
A389 846E 03381 LOOP014 STY L.ZPOSOFF ; Save offset to z-coordinate
A38B 18 03382 CLC ;
03383
A38C 98 03384 TYA ;
A38D AA 03385 TAX ; X := offset to z-coordinate
A38E 6931 03386 ADC #NUMSPCOBJ.ALL ;
A390 A8 03387 TAY ; Y := offset to x-coordinate
A391 209BB6 03388 JSR ROTATE ; Calc new x-coordinate (horizontal rot @ y-axis)
03389
A394 98 03390 TYA ;
A395 AA 03391 TAX ; X := offset to x-coordinate
A396 A46E 03392 LDY L.ZPOSOFF ; Y := offset to z-coordinate
A398 209BB6 03393 JSR ROTATE ; Calc new z-coordinate (horizontal rot @ y-axis)
A39B 88 03394 DEY ;
A39C 10EB 03395 BPL LOOP014 ; Next space object
03396
03397 ;*** Rotate vertically *********************************************************
A39E A5C9 03398 SKIP008 LDA JOYSTICKY ; Skip if joystick centered vertically
A3A0 F019 03399 BEQ SKIP009 ;
03400
A3A2 856D 03401 STA JOYSTICKDELTA ; Save JOYSTICKY (used in subroutine ROTATE)
A3A4 A479 03402 LDY MAXSPCOBJIND ; Loop over all space objects in use
A3A6 846E 03403 LOOP015 STY L.ZPOSOFF ; Save offset to z-coordinate
A3A8 18 03404 CLC ;
03405
A3A9 98 03406 TYA ;
A3AA AA 03407 TAX ; X := offset to z-coordinate
A3AB 6962 03408 ADC #NUMSPCOBJ.ALL*2 ;
A3AD A8 03409 TAY ; Y := offset to y-coordinate
A3AE 209BB6 03410 JSR ROTATE ; Calc new y-coordinate (vertical rot @ x-axis)
03411
A3B1 98 03412 TYA ;
A3B2 AA 03413 TAX ; X := offset to y-coordinate
A3B3 A46E 03414 LDY L.ZPOSOFF ; Y := offset to z-coordinate
A3B5 209BB6 03415 JSR ROTATE ; Calc new z-coordinate (vertical rot @ x-axis)
A3B8 88 03416 DEY ;
A3B9 10EB 03417 BPL LOOP015 ; Next space object
03418
03419 ;*** (9) Move all space objects along z-axis (toward our starship) *************
A3BB A679 03420 SKIP009 LDX MAXSPCOBJIND ; Loop over all space objects in use
A3BD E005 03421 LOOP016 CPX #NUMSPCOBJ.PL ; Skip if PLAYFIELD space object (X index > 4)
A3BF B005 03422 BCS SKIP010 ;
03423
A3C1 BD8C0C 03424 LDA PL0SHAPTYPE,X ; Skip if next PLAYER space obj is PHOTON TORPEDO (!)
A3C4 F019 03425 BEQ SKIP011 ;
03426
A3C6 38 03427 SKIP010 SEC ; New z-coordinate := old z-coordinate -
A3C7 BDD30A 03428 LDA ZPOSLO,X ; ...our starship's velocity
A3CA E570 03429 SBC VELOCITYLO ; (signed 24-bit subtraction)
A3CC 9DD30A 03430 STA ZPOSLO,X ;
A3CF BD400A 03431 LDA ZPOSHI,X ;
A3D2 E5C1 03432 SBC VELOCITYHI ;
A3D4 9D400A 03433 STA ZPOSHI,X ;
A3D7 BDAD09 03434 LDA ZPOSSIGN,X ;
A3DA E900 03435 SBC #0 ;
A3DC 9DAD09 03436 STA ZPOSSIGN,X ;
03437
A3DF CA 03438 SKIP011 DEX ;
A3E0 10DB 03439 BPL LOOP016 ; Next space object
03440
03441 ;*** (10) Add space object's velocity vector to space object's position vector *
A3E2 A679 03442 LDX MAXSPCOBJIND ; Loop over all space objects in use
A3E4 E010 03443 LOOP017 CPX #NUMSPCOBJ.NORM-1 ; Skip if space object is star (X index 5..16)...
A3E6 D002 03444 BNE SKIP012 ; ...because stars don't move by themselves
A3E8 A204 03445 LDX #4 ;
03446
A3EA 8A 03447 SKIP012 TXA ;
A3EB A8 03448 LOOP018 TAY ; Loop over all 3 coordinates
03449
A3EC A900 03450 LDA #0 ; Expand 8-bit velocity vector component to 16-bit:
A3EE 856B 03451 STA L.VELOCITYHI ; ...16-bit velocity (high byte) = L.VELOCITYHI := 0
A3F0 B9660B 03452 LDA ZVEL,Y ; ...16-bit velocity (low byte) = A := ZVEL,Y
A3F3 1009 03453 BPL SKIP013 ; Skip if 16-bit velocity >= 0 (positive)
03454
A3F5 497F 03455 EOR #$7F ; 16-bit velocity < 0 (negative)...
A3F7 18 03456 CLC ; ...calculate two's-complement of 16-bit velocity
A3F8 6901 03457 ADC #1 ;
A3FA B002 03458 BCS SKIP013 ;
A3FC C66B 03459 DEC L.VELOCITYHI ;
03460
A3FE 18 03461 SKIP013 CLC ; New coordinate := old coordinate + 16-bit velocity
A3FF 79D30A 03462 ADC ZPOSLO,Y ; (signed 24-bit addition)
A402 99D30A 03463 STA ZPOSLO,Y ;
A405 B9400A 03464 LDA ZPOSHI,Y ;
A408 656B 03465 ADC L.VELOCITYHI ;
A40A 99400A 03466 STA ZPOSHI,Y ;
A40D B9AD09 03467 LDA ZPOSSIGN,Y ;
A410 656B 03468 ADC L.VELOCITYHI ;
A412 99AD09 03469 STA ZPOSSIGN,Y ;
03470
A415 98 03471 TYA ;
A416 18 03472 CLC ;
A417 6931 03473 ADC #NUMSPCOBJ.ALL ;
A419 C990 03474 CMP #144 ; (!)
A41B 90CE 03475 BCC LOOP018 ; Next coordinate
03476
A41D CA 03477 DEX ;
A41E 10C4 03478 BPL LOOP017 ; Next space object
03479
03480 ;*** (11) Correct over/underflow of PLAYER space objects' position vector ******
A420 A004 03481 LDY #NUMSPCOBJ.PL-1 ;
A422 98 03482 LOOP019 TYA ; Loop over all PLAYER space objects (X index < 5)
A423 AA 03483 TAX ;
03484
A424 A902 03485 LDA #2 ; Loop over all 3 coordinates
A426 856A 03486 STA L.VECCOMPIND ;
03487
A428 BDAD09 03488 LOOP020 LDA ZPOSSIGN,X ; Load sign of coordinate
A42B C902 03489 CMP #2 ;
A42D 9010 03490 BCC SKIP015 ; Skip if sign = 0 (negative) or 1 (positive)
03491
A42F 0A 03492 ASL A ; SUMMARY: Space object out-of-bounds correction
A430 A900 03493 LDA #0 ; If new coordinate > +65535 <KM> subtract 256 <KM>
A432 9DAD09 03494 STA ZPOSSIGN,X ; ...until new coordinate <= +65535 <KM>
A435 B005 03495 BCS SKIP014 ; If new coordinate < -65536 <KM> add 256 <KM>
A437 FEAD09 03496 INC ZPOSSIGN,X ; ...until new coordinate >= -65536 <KM>
A43A 49FF 03497 EOR #$FF ;
A43C 9D400A 03498 SKIP014 STA ZPOSHI,X ;
03499
A43F 8A 03500 SKIP015 TXA ;
A440 18 03501 CLC ;
A441 6931 03502 ADC #NUMSPCOBJ.ALL ;
A443 AA 03503 TAX ;
A444 C66A 03504 DEC L.VECCOMPIND ;
A446 10E0 03505 BPL LOOP020 ; Next coordinate
03506
A448 88 03507 DEY ;
A449 10D7 03508 BPL LOOP019 ; Next space object
03509
03510 ;*** (12) Calc perspective projection of space objects *************************
A44B A5D0 03511 LDA SHIPVIEW ; Skip if in Long-Range Scan or Galactic Chart view
A44D C902 03512 CMP #$02 ;
A44F B05C 03513 BCS SKIP019 ;
03514
A451 A679 03515 LDX MAXSPCOBJIND ; Loop over all space objects in use
A453 A9FF 03516 LOOP021 LDA #255 ; Prep magic offscreen pixel number value
A455 BCAD09 03517 LDY ZPOSSIGN,X ; Compare sign of z-coordinate with view mode
A458 C4D0 03518 CPY SHIPVIEW ;
A45A F04B 03519 BEQ SKIP018 ; Equal? Space object is offscreen -> New space obj!
03520
A45C BD0F0A 03521 LDA YPOSSIGN,X ; Prepare projection division...
A45F D012 03522 BNE SKIP016 ; DIVIDEND (16-bit value) := ABS(y-coordinate)
A461 38 03523 SEC ; (used in subroutine PROJECTION)
A462 A900 03524 LDA #0 ;
A464 FD350B 03525 SBC YPOSLO,X ;
A467 856A 03526 STA DIVIDEND ;
A469 A900 03527 LDA #0 ;
A46B FDA20A 03528 SBC YPOSHI,X ;
A46E 856B 03529 STA DIVIDEND+1 ;
A470 4C7DA4 03530 JMP JUMP001 ;
A473 BD350B 03531 SKIP016 LDA YPOSLO,X ;
A476 856A 03532 STA DIVIDEND ;
A478 BDA20A 03533 LDA YPOSHI,X ;
A47B 856B 03534 STA DIVIDEND+1 ;
03535
A47D 2021AA 03536 JUMP001 JSR PROJECTION ; Calc pixel row number rel. to screen center
A480 201EB7 03537 JSR SCREENROW ; Calc pixel row number rel. to top-left of screen
03538
A483 BDDE09 03539 LDA XPOSSIGN,X ; Prepare projection division...
A486 D012 03540 BNE SKIP017 ; DIVIDEND (16-bit value) := ABS(x-coordinate)
A488 38 03541 SEC ; (used in subroutine PROJECTION)
A489 A900 03542 LDA #0 ;
A48B FD040B 03543 SBC XPOSLO,X ;
A48E 856A 03544 STA DIVIDEND ;
A490 A900 03545 LDA #0 ;
A492 FD710A 03546 SBC XPOSHI,X ;
A495 856B 03547 STA DIVIDEND+1 ;
A497 4CA4A4 03548 JMP JUMP002 ;
A49A BD040B 03549 SKIP017 LDA XPOSLO,X ;
A49D 856A 03550 STA DIVIDEND ;
A49F BD710A 03551 LDA XPOSHI,X ;
A4A2 856B 03552 STA DIVIDEND+1 ;
03553
A4A4 2021AA 03554 JUMP002 JSR PROJECTION ; Calc pixel column number rel. to screen center
A4A7 20FBB6 03555 SKIP018 JSR SCREENCOLUMN ; Calc pixel column number rel. to top-left of screen
A4AA CA 03556 DEX ;
A4AB 10A6 03557 BPL LOOP021 ; Next space object
03558
03559 ;*** (13) Handle hyperwarp marker selection in Galactic Chart view *************
A4AD 2062B1 03560 SKIP019 JSR SELECTWARP ; Handle hyperwarp marker in Galactic Chart view
03561
03562 ;*** (14) Compute and draw Long-Range Scan view star field on z-x plane ********
A4B0 24D0 03563 BIT SHIPVIEW ; Skip if not in Long-Range Scan view
A4B2 5031 03564 BVC SKIP022 ;
03565
A4B4 A231 03566 LDX #$31 ; Draw our starship's shape
A4B6 206FA7 03567 JSR DRAWLINES ;
03568
A4B9 2C9609 03569 BIT GCSTATLRS ; Skip if Long-Range Scan destroyed
A4BC 7027 03570 BVS SKIP022 ;
03571
A4BE A679 03572 LDX MAXSPCOBJIND ; Loop over all space objects in use
A4C0 BD400A 03573 LOOP022 LDA ZPOSHI,X ; Load z-coordinate (high byte)
A4C3 BCAD09 03574 LDY ZPOSSIGN,X ; Load sign of z-coordinate
A4C6 D002 03575 BNE SKIP020 ;
A4C8 49FF 03576 EOR #$FF ; A := ABS(z-coordinate (high byte))
A4CA A8 03577 SKIP020 TAY ;
A4CB B9E90D 03578 LDA MAPTO80,Y ; Calc pixel row number rel. to screen center
A4CE 201EB7 03579 JSR SCREENROW ; Calc pixel row number rel. to top-left of screen
03580
A4D1 BD710A 03581 LDA XPOSHI,X ; Load x-coordinate (high byte)
A4D4 BCDE09 03582 LDY XPOSSIGN,X ; Load sign of x-coordinate
A4D7 D002 03583 BNE SKIP021 ;
A4D9 49FF 03584 EOR #$FF ; A := ABS(x-coordinate (high byte))
A4DB A8 03585 SKIP021 TAY ;
A4DC B9E90D 03586 LDA MAPTO80,Y ; Calc pixel column number rel. to screen center
A4DF 20FBB6 03587 JSR SCREENCOLUMN ; Calc pixel column number rel. to top-left of screen
03588
A4E2 CA 03589 DEX ;
A4E3 10DB 03590 BPL LOOP022 ; Next space object
03591
03592 ;*** (15) Update PLAYER shapes, heights, and colors ****************************
03593
03594 ; DESCRIPTION
03595 ;
03596 ; In a loop over all PLAYERs, the following steps are executed:
03597 ;
03598 ; o Clear the PLAYER shape offset and height.
03599 ;
03600 ; o If in Galactic Chart view or in Long-Range Scan view, preload a random
03601 ; color and a magic z-coordinate (distance value) for PLAYER3..4
03602 ; (representing hyperwarp markers in Galactic Chart view and blips in the
03603 ; Long-Range Scan view, like, for example, Zylon ships, meteors - or even
03604 ; the Hyperwarp Target Marker during hyperwarp!).
03605 ;
03606 ; o If in Front or Aft view, execute the following steps:
03607 ;
03608 ; o Skip dead PLAYERs.
03609 ;
03610 ; o Preload the distance value for the remaining live PLAYERs.
03611 ;
03612 ; o If we are in a starbase sector, combine PLAYER0..2 into a three-part
03613 ; starbase shape. Compute the pixel column numbers and pixel row
03614 ; numbers of PLAYER0..1 such that they are arranged left (PLAYER0) and
03615 ; right (PLAYER1) of PLAYER2. In addition, preload a color mask, a
03616 ; counter actually, that will make the starbase pulsate in brightness.
03617 ;
03618 ; BUG (at $A512): The code at $A512 that skips the combination operation for
03619 ; PLAYER2..4 jumps for PLAYER3..4 to SKIP025 at $A52A instead of SKIP026 at
03620 ; $A52E. Thus it stores a color mask which does not only make the starbase
03621 ; PLAYER0..2 pulsate in brightness but also PLAYER3..4 in a starbase sector,
03622 ; for example the transfer vessel, photon torpedoes, etc. - or even the
03623 ; Hyperwarp Target Marker when hyperwarping out of such a sector! Suggested
03624 ; fix: None, code hard to untwist.
03625 ;
03626 ; o After storing the color mask, check if the PLAYER shape is still above the
03627 ; bottom edge of the PLAYFIELD.
03628 ;
03629 ; BUG (at $A534): The test checks the vertical position of the top edge of
03630 ; the PLAYER against the bottom edge of the PLAYFIELD above the Console
03631 ; Panel Display (= Player/Missile pixel row number 204). This is not
03632 ; completely accurate as the Console Panel Display starts at PM pixel row
03633 ; number 208. For example, if you carefully navigate a starbase to the
03634 ; bottom edge of the PLAYFIELD, at a certain point the center of the
03635 ; starbase shape bleeds over the bottom edge of the PLAYFIELD (while
03636 ; sometimes even losing its left and right wings!). Suggested fix: None, as
03637 ; a more elaborate test may consume too many bytes of the cartridge ROM
03638 ; memory in order to fix a rarely noticed visual glitch.
03639 ;
03640 ; o Convert the preloaded distance value of a PLAYER space object closer than
03641 ; $2000 (8192) <KM> into a range index of 0..15. PLAYER space objects more
03642 ; distant than $2000 (8192) <KM> are skipped and not displayed.
03643 ;
03644 ; Later, this range index will pick not only the correct brightness for the
03645 ; PLAYER (the closer the space object the brighter its PLAYER) but also the
03646 ; correct PLAYER shape cell and height (the closer the space object the
03647 ; larger the PLAYER shape and height).
03648 ;
03649 ; o Update the PLAYER's shape offset and height. On the way to the shape
03650 ; offset and height add the PLAYER's shape type to the range index and
03651 ; divide it by 2 to arrive at the shape offset index and height index (the
03652 ; same value). Use this index to pick the correct shape data and shape
03653 ; heights from a set of shape cells and their corresponding heights, stored
03654 ; in tables PLSHAPOFFTAB ($BE2F) and PLSHAPHEIGHTTAB ($BE7F), respectively.
03655 ;
03656 ; Remember that magic distance value used in the Galactic Chart and
03657 ; Long-Range Scan view? Its value of $F2 is actually part of a negative
03658 ; z-coordinate which is inverted to $0D00, leading to a range index of 13,
03659 ; which, after the division by 2, picks shape cell 6. Shape cell 6 (the
03660 ; seventh shape cell) of all space objects (except the starbase) is the
03661 ; Long-Range Scan blip's dot (see PLSHAPOFFTAB ($BE2F) and PLSHAPHEIGHTTAB
03662 ; ($BE7F)).
03663 ;
03664 ; o Update the PLAYER's color/brightness by picking the appropriate values
03665 ; with the range index from lookup tables PLSHAPCOLORTAB ($BFD1) and
03666 ; PLSHAPBRITTAB ($BFDB). Apply some special effects to the color/brightness
03667 ; of certain PLAYERs, such as using random colors for Zylon basestars, or
03668 ; using the precomputed pulsating brightness value for a starbase.
03669
A4E5 A205 03670 SKIP022 LDX #NUMSPCOBJ.PL ; Loop over all PLAYER space objects (X index < 5)
A4E7 CA 03671 LOOP023 DEX ;
A4E8 1003 03672 BPL SKIP023 ; Jump into loop body below
A4EA 4C79A5 03673 JMP JUMP003 ; Loop is finished, skip loop body
03674
03675 ;*** Clear PLAYER shape offsets and heights ************************************
A4ED A900 03676 SKIP023 LDA #0 ;
A4EF 95E4 03677 STA PL0SHAPOFF,X ; Clear PLAYER shape offset
A4F1 9DEE0C 03678 STA PL0HEIGHTNEW,X ; Clear new PLAYER shape height
03679
03680 ;*** Preload stuff for hyperwarp markers and Long-Range Scan blips *************
A4F4 24D0 03681 BIT SHIPVIEW ; Skip if not in Galactic Chart view
A4F6 100B 03682 BPL SKIP024 ;
03683
A4F8 E003 03684 CPX #3 ; Next PLAYER space object if PLAYER0..2
A4FA 90EB 03685 BCC LOOP023 ;
03686
A4FC AD0AD2 03687 LOOP024 LDA RANDOM ; Prep random color mask for warp markers/LRS blips
A4FF A0F2 03688 LDY #$F2 ; Prep magic z-coordinate for warp markers/LRS blips
A501 302B 03689 BMI SKIP026 ; Unconditional jump
03690
A503 D5E9 03691 SKIP024 CMP PL0LIFE,X ; Next PLAYER space object if this PLAYER not alive
A505 F0E0 03692 BEQ LOOP023 ;
03693
A507 70F3 03694 BVS LOOP024 ; Skip back if in Long-Range Scan view
03695
03696 ;*** Preload stuff for other views *********************************************
03697
A509 BC400A 03698 LDY PL0ZPOSHI,X ; Prep z-coordinate (high byte)
03699
03700 ;*** Combine PLAYER0..2 to starbase shape **************************************
A50C 247B 03701 BIT ISSTARBASESECT ; Skip if no starbase in this sector
A50E 501E 03702 BVC SKIP026 ;
03703
A510 E002 03704 CPX #2 ; Skip if PLAYER2..4
A512 B016 03705 BCS SKIP025 ; (!)
03706
A514 AD2C0C 03707 LDA PL2COLUMN ; Calc new PM pixel column number for PLAYER0..1:
A517 18 03708 CLC ; Load PLAYER2 (starbase center) pixel column number
A518 7DDBBE 03709 ADC PLSTARBAOFFTAB,X ; ...add PLAYER left/right offset (starbase wings)
A51B 9D2A0C 03710 STA PL0COLUMN,X ; Store new PM pixel column number of starbase wing
03711
A51E ADFB0B 03712 LDA PL2ROWNEW ; Calc new PM pixel row number for PLAYER0..1:
A521 18 03713 CLC ; Add vertical offset (= 4 PM pixels) to PLAYER2's
A522 6904 03714 ADC #4 ;
A524 9DF90B 03715 STA PL0ROWNEW,X ; Store new PM pixel row number of starbase wing
03716
A527 AC420A 03717 LDY PL2ZPOSHI ; Prep Y with z-coordinate (high byte) of starbase
03718
A52A A576 03719 SKIP025 LDA COUNT256 ; Prep color mask with B3..0 of counter
A52C 290F 03720 AND #$0F ; ...(= brightness bits cause pulsating brightness)
03721
A52E 856B 03722 SKIP026 STA L.COLORMASK ; Store color mask
03723
03724 ;*** Check if PLAYER is below PLAYFIELD bottom edge ****************************
A530 98 03725 TYA ; A := z-coordinate (high byte)
03726
A531 BCF90B 03727 LDY PL0ROWNEW,X ; Next PLAYER space object if top of PM shape...
A534 C0CC 03728 CPY #204 ; ...is below PLAYFIELD bottom... (!)
A536 B0AF 03729 BCS LOOP023 ; ...(PM pixel row number >= 204)
03730
03731 ;*** Convert PLAYER z-coordinate to range index in 0..15 ***********************
A538 A4D0 03732 LDY SHIPVIEW ; Skip if in Front view...
A53A F002 03733 BEQ SKIP027 ;
A53C 49FF 03734 EOR #$FF ; ...else invert z-coordinate (high byte)
03735
A53E C920 03736 SKIP027 CMP #$20 ; Next PLAYER space object if this one too far away
A540 B0A5 03737 BCS LOOP023 ; ...(z-coordinate >= $20** (8192) <KM>)
03738
A542 C910 03739 CMP #16 ; Load z-coordinate (high byte) and...
A544 9002 03740 BCC SKIP028 ;
A546 A90F 03741 LDA #15 ;
A548 856A 03742 SKIP028 STA L.RANGEINDEX ; ...trim to range index in 0..15
03743
03744 ;*** Update PLAYER shape offset and height *************************************
A54A 1D8C0C 03745 ORA PL0SHAPTYPE,X ; Calc offset to shape table (shape type+range index)
A54D 4A 03746 LSR A ;
A54E A8 03747 TAY ; Divide by 2 to get offset in 0..7 into shape data
A54F B92FBE 03748 LDA PLSHAPOFFTAB,Y ; Update new PLAYER shape offset
A552 95E4 03749 STA PL0SHAPOFF,X ;
A554 B97FBE 03750 LDA PLSHAPHEIGHTTAB,Y ; Update new PLAYER shape height
A557 9DEE0C 03751 STA PL0HEIGHTNEW,X ;
03752
03753 ;*** Calculate PLAYER color/brightness value ***********************************
A55A 98 03754 TYA ; Pick color (B7..4) using PLAYER shape type
A55B 4A 03755 LSR A ;
A55C 4A 03756 LSR A ;
A55D 4A 03757 LSR A ;
A55E A8 03758 TAY ;
A55F B9D1BF 03759 LDA PLSHAPCOLORTAB,Y ;
A562 C008 03760 CPY #8 ; Pick random color if ZYLON BASESTAR (shape type 8)
A564 D003 03761 BNE SKIP029 ;
A566 4D0AD2 03762 EOR RANDOM ;
A569 A46A 03763 SKIP029 LDY L.RANGEINDEX ;
A56B 59DBBF 03764 EOR PLSHAPBRITTAB,Y ; Pick brightness (B3..0) using range index and merge
03765
A56E 456B 03766 EOR L.COLORMASK ; Modify color/brightness of PLAYER
03767
A570 BCDFB8 03768 LDY PLCOLOROFFTAB,X ; Get PLAYER color offset
A573 99EE00 03769 STA PL0COLOR,Y ; Store color in PLAYER color register
A576 4CE7A4 03770 JMP LOOP023 ; Next PLAYER space object
03771
03772 ;*** (16) Flash red alert ******************************************************
A579 A0AF 03773 JUMP003 LDY #$AF ; Prep PLAYFIELD2 color {BRIGHT BLUE-GREEN}
A57B A681 03774 LDX SHIELDSCOLOR ; Prep Shields color {DARK GREEN} or {BLACK}
03775
A57D A58B 03776 LDA REDALERTLIFE ; Skip if red alert is over
A57F F00C 03777 BEQ SKIP030 ;
03778
A581 C68B 03779 DEC REDALERTLIFE ; Decrement lifetime of red alert
A583 A04F 03780 LDY #$4F ; Prep PLAYFIELD2 color {BRIGHT ORANGE}
03781
A585 2920 03782 AND #$20 ; Switch colors every 64 game loops
A587 F004 03783 BEQ SKIP030 ;
03784
A589 A242 03785 LDX #$42 ; Load BACKGROUND color {DARK ORANGE}
A58B A060 03786 LDY #$60 ; Load PLAYFIELD2 color {DARK PURPLE BLUE}
03787
A58D 84F4 03788 SKIP030 STY PF2COLOR ; Store PLAYFIELD2 color
A58F 86F6 03789 STX BGRCOLOR ; Store BACKGROUND color
03790
03791 ;*** (17) Update color of PLAYFIELD space objects (stars, explosion fragments) *
A591 A679 03792 LDX MAXSPCOBJIND ; Loop over all PLAYFIELD space objs (X index > 4)
A593 BD400A 03793 LOOP025 LDA ZPOSHI,X ; Prep z-coordinate (high byte)
A596 A4D0 03794 LDY SHIPVIEW ;
A598 C001 03795 CPY #1 ; Skip if not in Aft view
A59A D009 03796 BNE SKIP032 ;
03797
A59C C9F0 03798 CMP #$F0 ; Skip if star not too far (z < $F0** (-4096) <KM>)
A59E B003 03799 BCS SKIP031 ;
A5A0 2064B7 03800 JSR INITPOSVEC ; Re-init position vector
A5A3 49FF 03801 SKIP031 EOR #$FF ; Invert z-coordinate (high byte)
03802
A5A5 C910 03803 SKIP032 CMP #16 ; Convert z-coordinate (high byte)
A5A7 9002 03804 BCC SKIP033 ; ...into range index 0..15
A5A9 A90F 03805 LDA #15 ;
03806
A5AB 0A 03807 SKIP033 ASL A ; Compute index to pixel color table:
A5AC 291C 03808 AND #$1C ; Use bits B3..1 from range index as B4..2.
A5AE 0572 03809 ORA COUNT8 ; Combine with random bits B3..0 from counter
03810
A5B0 A8 03811 TAY ;
A5B1 B990BA 03812 LDA FOURCOLORPIXEL,Y ; Load 1-byte bit pattern for 4 pixels of same color
A5B4 856A 03813 STA L.FOURCOLORPIX ; ...and temporarily save it
03814
A5B6 BD2A0C 03815 LDA PIXELCOLUMN,X ; Load pixel mask to mask 1 pixel out of 4 pixels:
A5B9 2903 03816 AND #$03 ; Use B1..0 from pixel column number...
A5BB A8 03817 TAY ;
A5BC B9B0BA 03818 LDA PIXELMASKTAB,Y ; ...to pick mask to filter pixel in byte
A5BF 256A 03819 AND L.FOURCOLORPIX ; ...AND with 1-byte bit pattern for 4 pixels
A5C1 9DEE0C 03820 STA PIXELBYTE,X ; ...store byte (used in repaint step of game loop)
03821
A5C4 CA 03822 DEX ;
A5C5 E005 03823 CPX #NUMSPCOBJ.PL ;
A5C7 B0CA 03824 BCS LOOP025 ; Next PLAYFIELD space object
03825
03826 ;*** (18) Skip input handling if in demo mode **********************************
A5C9 2464 03827 BIT ISDEMOMODE ; If in demo mode skip to function keys
A5CB 5003 03828 BVC SKIP034 ;
A5CD 4C9BA6 03829 JMP SKIP040 ;
03830
03831 ;*** (19) Handle keyboard input ************************************************
A5D0 20FEAF 03832 SKIP034 JSR KEYBOARD ; Handle keyboard input
03833
03834 ;*** (20) Handle joystick input ************************************************
A5D3 AD00D3 03835 LDA PORTA ; Load Joystick 0 directions
A5D6 A8 03836 TAY ; ...Bits B0..3 -> Right, left, down, up.
A5D7 2903 03837 AND #$03 ; ...Bit = 0/1 -> Stick pressed/not pressed
A5D9 AA 03838 TAX ; JOYSTICKY := +1 -> Up
A5DA BDF5BA 03839 LDA STICKINCTAB,X ; JOYSTICKY := 0 -> Centered
A5DD 85C9 03840 STA JOYSTICKY ; JOYSTICKY := -1 -> Down
A5DF 98 03841 TYA ;
A5E0 4A 03842 LSR A ;
A5E1 4A 03843 LSR A ;
A5E2 2903 03844 AND #$03 ;
A5E4 AA 03845 TAX ; JOYSTICKX := -1 -> Left
A5E5 BDF5BA 03846 LDA STICKINCTAB,X ; JOYSTICKX := 0 -> Centered
A5E8 85C8 03847 STA JOYSTICKX ; JOYSTICKX := +1 -> Right
03848
03849 ;*** (21) Check if our starship's photon torpedoes have hit a target ***********
A5EA 203DAF 03850 JSR COLLISION ; Check if our starship's photon torpedoes have hit
03851
03852 ;*** (22) Handle joystick trigger **********************************************
A5ED 2029AE 03853 JSR TRIGGER ; Handle joystick trigger
03854
03855 ;*** (23) Handle Attack Computer and Tracking Computer *************************
A5F0 2C9509 03856 BIT GCSTATCOM ; Skip if Attack Computer destroyed
A5F3 7040 03857 BVS SKIP038 ;
03858
A5F5 A57E 03859 LDA DRAINATTCOMP ; Skip if Attack Computer off
A5F7 F03C 03860 BEQ SKIP038 ;
03861
A5F9 A5D0 03862 LDA SHIPVIEW ; Skip if not in Front view
A5FB D003 03863 BNE SKIP035 ;
03864
A5FD 20BFA7 03865 JSR UPDATTCOMP ; Update Attack Computer Display
03866
A600 AE5C09 03867 SKIP035 LDX TRACKDIGIT ; Load index of tracked space object
03868
A603 A5BF 03869 LDA ZYLONATTACKER ; Skip if ship of current Zylon torpedo is tracked
A605 3005 03870 BMI SKIP036 ;
A607 AA 03871 TAX ; ...else override Tracking Computer...
A608 0980 03872 ORA #$80 ;
A60A 85BF 03873 STA ZYLONATTACKER ; ...and mark Zylon torpedo's ship as being tracked
03874
A60C B5E9 03875 SKIP036 LDA PL0LIFE,X ; Skip if tracked space object still alive
A60E D00B 03876 BNE SKIP037 ;
03877
A610 8A 03878 TXA ;
A611 4901 03879 EOR #$01 ;
A613 AA 03880 TAX ;
A614 B5E9 03881 LDA PL0LIFE,X ; Check if other Zylon ship still alive
A616 D003 03882 BNE SKIP037 ; ...yes -> Keep new index
A618 AE5C09 03883 LDX TRACKDIGIT ; ...no -> Revert to old index of tracked space obj
03884
A61B 8E5C09 03885 SKIP037 STX TRACKDIGIT ; Store index of tracked space object
03886
A61E A57C 03887 LDA ISTRACKCOMPON ; Skip if tracking computer is turned off
A620 F013 03888 BEQ SKIP038 ;
03889
A622 A5D0 03890 LDA SHIPVIEW ; Skip if in Long-Range Scan or Galactic Chart view
A624 C902 03891 CMP #2 ;
A626 B00D 03892 BCS SKIP038 ;
03893
A628 4901 03894 EOR #$01 ;
A62A DDAD09 03895 CMP ZPOSSIGN,X ; Skip if tracked space object in our starship's...
A62D F006 03896 BEQ SKIP038 ; ...view direction
03897
A62F AA 03898 TAX ;
A630 BDCFBE 03899 LDA TRACKKEYSTAB,X ; Pick 'F' or 'A' (Front or Aft view) keyboard code
A633 85CA 03900 STA KEYCODE ; ...and store it (= emulate pressing 'F' or 'A' key)
03901
03902 ;*** (24) Handle docking to starbase *******************************************
A635 20E6AC 03903 SKIP038 JSR DOCKING ; Handle docking to starbase
03904
03905 ;*** (25) Handle maneuvering ***************************************************
A638 2079AA 03906 JSR MANEUVER ; Handle maneuvering photon torpedoes and Zylon ships
03907
03908 ;*** (26) Was our starship hit by Zylon photon torpedo? ************************
A63B A57B 03909 LDA ISSTARBASESECT ; Skip hit check if in starbase sector
A63D D05C 03910 BNE SKIP040 ;
03911
A63F A5EB 03912 LDA PL2LIFE ; Skip hit check if PLAYER2 (Zylon photon torpedo)...
A641 F058 03913 BEQ SKIP040 ; ...not alive
03914
A643 AC420A 03915 LDY PL2ZPOSHI ; Our starship was not hit if Zylon photon torpedo's
A646 C8 03916 INY ; ...z-coordinate is not in -256..255 <KM> or...
A647 C002 03917 CPY #$02 ;
A649 B050 03918 BCS SKIP040 ;
03919
A64B AC730A 03920 LDY PL2XPOSHI ; ...x-coordinate is not in -256..255 <KM> or...
A64E C8 03921 INY ;
A64F C002 03922 CPY #$02 ;
A651 B048 03923 BCS SKIP040 ;
03924
A653 ACA40A 03925 LDY PL2YPOSHI ; ...y-coordinate is not in -256..255 <KM>.
A656 C8 03926 INY ;
A657 C002 03927 CPY #$02 ;
A659 B040 03928 BCS SKIP040 ;
03929
03930 ;*** (27) Our starship was hit! ************************************************
A65B 20E1AE 03931 JSR DAMAGE ; Damage or destroy some subsystem
03932
A65E A002 03933 LDY #2 ; Trigger explosion at PLAYER2 (Zylon photon torpedo)
A660 206BAC 03934 JSR INITEXPL ;
03935
A663 A27F 03936 LDX #$7F ; Prep HITBADNESS := SHIELDS HIT
A665 A581 03937 LDA SHIELDSCOLOR ; Skip if Shields are up (SHIELDSCOLOR not {BLACK}).
A667 D01E 03938 BNE SKIP039 ;
03939
A669 A20A 03940 LDX #$0A ; Set Front view
A66B 2045B0 03941 JSR SETVIEW ;
03942
A66E A023 03943 LDY #$23 ; Set title phrase "SHIP DESTROYED BY ZYLON FIRE"
A670 A208 03944 LDX #8 ; Set mission bonus offset
A672 200AB1 03945 JSR GAMEOVER ; Game over
03946
A675 A25F 03947 LDX #$5F ; Hide Control Panel Display (bottom text window)
A677 A080 03948 LDY #$80 ;
A679 A908 03949 LDA #$08 ;
A67B 20F1AD 03950 JSR MODDLST ;
03951
A67E 200DAE 03952 JSR CLRPLAYFIELD ; Clear PLAYFIELD
03953
A681 A240 03954 LDX #64 ; Enable STARSHIP EXPLOSION noise (see SOUND)
A683 86E3 03955 STX NOISEHITLIFE ;
03956
A685 A2FF 03957 LDX #$FF ; Prep HITBADNESS := STARSHIP DESTROYED
03958
A687 868A 03959 SKIP039 STX HITBADNESS ; Store HITBADNESS
A689 A900 03960 LDA #0 ; Zylon photon torpedo lifetime := 0 game loops
A68B 85EB 03961 STA PL2LIFE ;
A68D A902 03962 LDA #2 ; Init Zylon photon torpedo trigger
A68F 85BE 03963 STA TORPEDODELAY ;
03964
A691 A201 03965 LDX #1 ; ENERGY := ENERGY - 100 after photon torpedo hit
A693 206FB8 03966 JSR DECENERGY ;
03967
A696 A20A 03968 LDX #$0A ; Play noise sound pattern SHIELD EXPLOSION
A698 20A8AE 03969 JSR NOISE ;
03970
03971 ;*** (28) Handle function keys *************************************************
A69B A463 03972 SKIP040 LDY FKEYCODE ; Prep old function key code
A69D AD1FD0 03973 LDA CONSOL ; POKEY: Load function key code
03974
A6A0 49FF 03975 EOR #$FF ; Store inverted and masked function key code
A6A2 2903 03976 AND #$03 ;
A6A4 8563 03977 STA FKEYCODE ;
A6A6 F01A 03978 BEQ SKIP042 ; Skip if no function key pressed
03979
A6A8 88 03980 DEY ;
A6A9 1017 03981 BPL SKIP042 ; Skip if SELECT or START still pressed
A6AB 8566 03982 STA IDLECNTHI ; Reset idle counter to a value in 1..3 (?)
A6AD C902 03983 CMP #2 ; Skip if SELECT function key pressed
A6AF B006 03984 BCS SKIP041 ;
03985
A6B1 A900 03986 LDA #0 ; START function key pressed:
A6B3 A8 03987 TAY ; Prep empty title phrase offset
A6B4 4C5EA1 03988 JMP INITSTART ; Reenter game loop via INITSTART
03989
A6B7 E662 03990 SKIP041 INC MISSIONLEVEL ; SELECT function key pressed:
A6B9 A562 03991 LDA MISSIONLEVEL ; Cycle through next of 4 mission levels
A6BB 2903 03992 AND #$03 ;
A6BD 8562 03993 STA MISSIONLEVEL ;
A6BF 4C5AA1 03994 JMP INITSELECT ; Reenter game loop via INITSELECT
03995
03996 ;*** (29) Update Control Panel Display *****************************************
A6C2 2004B8 03997 SKIP042 JSR UPDPANEL ; Update Control Panel Display
03998
03999 ;*** (30) Handle hyperwarp *****************************************************
A6C5 209BA8 04000 JSR HYPERWARP ; Handle hyperwarp
04001
04002 ;*** (31) Update title line ****************************************************
A6C8 2016B2 04003 JSR UPDTITLE ; Update title line
04004
04005 ;*** (32) Flush game loop iteration ********************************************
A6CB 20E4B4 04006 JSR FLUSHGAMELOOP ; Move Zylon units, age torpedoes, elapse time
04007
04008 ;*** (33) Jump back to begin of game loop **************************************
A6CE 4CF3A1 04009 JMP GAMELOOP ; Next game loop iteration
04010
04011 ;*******************************************************************************
04012 ;* *
04013 ;* VBIHNDLR *
04014 ;* *
04015 ;* Vertical Blank Interrupt Handler *
04016 ;* *
04017 ;*******************************************************************************
04018
04019 ; DESCRIPTION
04020 ;
04021 ; This subroutine is executed during the Vertical Blank Interrupt (VBI) when the
04022 ; TV beam has reached the bottom-right corner of the TV screen and is switched
04023 ; off to return to the top-left position. This situation is called the "vertical
04024 ; blank phase".
04025 ;
04026 ; This subroutine signals its execution with flag ISVBISYNC ($67) (which is
04027 ; examined by GAMELOOP ($A1F3) to synchronize the execution of the game loop
04028 ; with the start of this subroutine). Then it switches the character set to the
04029 ; ROM character set, sets the BACKGROUND color depending on the severity of a
04030 ; Zylon photon torpedo hit and view mode, copies PLAYER and PLAYFIELD color
04031 ; registers to their corresponding hardware registers, clears the Player/Missile
04032 ; collision registers, calls the sound effects code in subroutine SOUND ($B2AB),
04033 ; and increments the idle counter. If the idle counter reaches the value $8000
04034 ; the title phrase is cleared and the game is switched to demo mode.
04035 ;
04036 ; BUG (at $A6EC): Because the values of SHIPVIEW ($D0) are $00, $01, $40, and
04037 ; $80, a value of 3 overspecifies the comparison. Suggested fix: Replace CMP #3
04038 ; with CMP #2, which may make the code clearer.
04039 ;
04040 ; BUG (at $A712): Demo mode is entered via a JMP instruction, which proceeds
04041 ; directly into GAMELOOP ($A1F3). Thus code execution never returns to pop the
04042 ; registers pushed on the stack during entry of this subroutine. Suggested fix:
04043 ; None.
04044
A6D1 A9FF 04045 VBIHNDLR LDA #$FF ; Signals entering Vertical Blank Interrupt
A6D3 8567 04046 STA ISVBISYNC ;
04047
A6D5 A9E0 04048 LDA #>ROMCHARSET ; Switch character set to ROM character set
A6D7 8D09D4 04049 STA CHBASE ;
04050
A6DA A6F6 04051 LDX BGRCOLOR ; Preload BACKGROUND color
A6DC AD0AD2 04052 LDA RANDOM ; Preload random number
A6DF 248A 04053 BIT HITBADNESS ; Check if our starship was hit
A6E1 5007 04054 BVC SKIP044 ; If HITBADNESS has a value of...
A6E3 3004 04055 BMI SKIP043 ; $00 -> NO HIT (BGR color := unchanged)
A6E5 2972 04056 AND #$72 ; $7F -> SHIELDS HIT (BGR color := %01rr00r0)
A6E7 0940 04057 ORA #$40 ; $FF -> STARSHIP DESTROYED (BGR color := %01rr00r0)
A6E9 AA 04058 SKIP043 TAX ;
A6EA A5D0 04059 SKIP044 LDA SHIPVIEW ; Skip if in Front or Aft view
A6EC C903 04060 CMP #3 ; (!)
A6EE 9002 04061 BCC SKIP045 ;
A6F0 A2A0 04062 LDX #$A0 ; Preload BACKGROUND color {DARK BLUE GREEN}...
A6F2 86F6 04063 SKIP045 STX BGRCOLOR ; Store BACKGROUND color
04064
A6F4 A208 04065 LDX #8 ; Copy all color registers to hardware registers
A6F6 B5EE 04066 LOOP026 LDA PL0COLOR,X ;
A6F8 9D12D0 04067 STA COLPM0,X ;
A6FB CA 04068 DEX ;
A6FC 10F8 04069 BPL LOOP026 ;
04070
A6FE 8D1ED0 04071 STA HITCLR ; Clear Player/Missile collision registers
04072
A701 20ABB2 04073 JSR SOUND ; Call sound effects
04074
A704 E677 04075 INC IDLECNTLO ; Increment 16-bit idle counter
A706 D00D 04076 BNE SKIP046 ;
A708 A566 04077 LDA IDLECNTHI ;
A70A 3009 04078 BMI SKIP046 ;
A70C E666 04079 INC IDLECNTHI ;
A70E 1005 04080 BPL SKIP046 ; Skip if idle counter value of $8000 not reached yet
04081
A710 A000 04082 LDY #$00 ; Prep empty title phrase offset
A712 4C5CA1 04083 JMP INITDEMO ; Enter demo mode (!)
04084
A715 4C4BA7 04085 SKIP046 JMP JUMP004 ; Return via DLI return code
04086
04087 ;*******************************************************************************
04088 ;* *
04089 ;* DLSTHNDLR *
04090 ;* *
04091 ;* Display List Interrupt Handler *
04092 ;* *
04093 ;*******************************************************************************
04094
04095 ; DESCRIPTION
04096 ;
04097 ; This subroutine is executed during the Display List Interrupt (DLI). It
04098 ; switches the character set to the ROM character set if the DLI occurs at ANTIC
04099 ; line 96 (video line 192), otherwise to the custom character set. The former
04100 ; happens in the Galactic Chart view where the ROM character set is used in the
04101 ; Galactic Chart Panel Display.
04102 ;
04103 ; Then, the DLI PLAYFIELD colors are copied to the corresponding hardware
04104 ; registers and the values of the collision hardware registers for PLAYER3..4
04105 ; (our starship's photon torpedoes) are copied to the corresponding zero page
04106 ; variables PL3HIT ($82) and PL4HIT ($83).
04107
A718 48 04108 DLSTHNDLR PHA ; Push A
A719 8A 04109 TXA ;
A71A 48 04110 PHA ; Push X
A71B 98 04111 TYA ;
A71C 48 04112 PHA ; Push Y
04113
A71D A9E0 04114 LDA #>ROMCHARSET ; Switch to ROM charset if ANTIC line counter = 96
A71F AC0BD4 04115 LDY VCOUNT ; ...else switch to custom character set
A722 C060 04116 CPY #96 ;
A724 F002 04117 BEQ SKIP047 ;
A726 A9A0 04118 LDA #>CHARSET ;
A728 8D09D4 04119 SKIP047 STA CHBASE ;
04120
A72B A204 04121 LDX #4 ; Loop over all PLAYFIELD colors
A72D 8D0AD4 04122 STA WSYNC ; Stop and wait for horizontal TV beam sync
A730 B5F7 04123 LOOP027 LDA PF0COLORDLI,X ; Copy DLI PLAYFIELD colors to hardware registers
A732 9D16D0 04124 STA COLPF0,X ;
A735 CA 04125 DEX ;
A736 10F8 04126 BPL LOOP027 ; Next PLAYFIELD color
04127
A738 AD08D0 04128 LDA M0PL ; Merge MISSILE-to-PLAYER collision registers...
A73B 0D09D0 04129 ORA M1PL ;
A73E 0D0AD0 04130 ORA M2PL ;
A741 0D0BD0 04131 ORA M3PL ;
A744 8583 04132 STA PL4HIT ; ...and store them in PL4HIT
A746 AD0FD0 04133 LDA P3PL ; Copy PLAYER3-to-PLAYER coll. register to PL3HIT
A749 8582 04134 STA PL3HIT ;
04135
A74B 68 04136 JUMP004 PLA ; Pop Y
A74C A8 04137 TAY ;
A74D 68 04138 PLA ; Pop X
A74E AA 04139 TAX ;
A74F 68 04140 PLA ; Pop A
A750 40 04141 RTI ; Return from interrupt
04142
04143 ;*******************************************************************************
04144 ;* *
04145 ;* IRQHNDLR *
04146 ;* *
04147 ;* Interrupt Request (IRQ) Handler *
04148 ;* *
04149 ;*******************************************************************************
04150
04151 ; DESCRIPTION
04152 ;
04153 ; This subroutine is executed during immediate interrupt requests (IRQs), such
04154 ; as after pressing a key on the keyboard. It clears and disables all IRQs
04155 ; except the interrupt raised by a pressed key. If a key has been pressed, its
04156 ; hardware code is collected and the bits of the SHIFT and CONTROL keys are
04157 ; added. The resulting keyboard code is stored in KEYCODE ($CA).
04158
A751 48 04159 IRQHNDLR PHA ; Push A
A752 A900 04160 LDA #0 ; POKEY: Disable all IRQs
A754 8D0ED2 04161 STA IRQEN ;
A757 A940 04162 LDA #$40 ; POKEY: Enable keyboard interrupt (IRQ)
A759 8D0ED2 04163 STA IRQEN ;
A75C AD09D2 04164 LDA KBCODE ; POKEY: Load keyboard key code
A75F 09C0 04165 ORA #$C0 ; Combine with SHIFT and CONTROL key bits
A761 85CA 04166 STA KEYCODE ; Store keyboard code
A763 68 04167 PLA ; Pop A
A764 40 04168 RTI ; Return from interrupt
04169
04170 ;*******************************************************************************
04171 ;* *
04172 ;* DRAWLINES *
04173 ;* *
04174 ;* Draw horizontal and vertical lines *
04175 ;* *
04176 ;*******************************************************************************
04177
04178 ; DESCRIPTION
04179 ;
04180 ; Draws the Attack Computer Display (in Front view), cross hairs (in Front and
04181 ; Aft view), and our starship's shape (in Long-Range Scan view) on the PLAYFIELD
04182 ; (if the Attack Computer is not destroyed) by being passed an offset to table
04183 ; DRAWLINESTAB ($BAF9). This table consists of a list of 3-byte elements,
04184 ; terminated by an end marker byte ($FE). Each such element defines a single
04185 ; horizontal or vertical line, and is passed via memory addresses DIRLEN ($A4),
04186 ; PENROW ($A5), and PENCOLUMN ($A6) to subroutine DRAWLINE ($A782), which
04187 ; executes the actual drawing. See subroutine DRAWLINE ($A782) and table
04188 ; DRAWLINESTAB ($BAF9) for a description of the 3-byte elements.
04189 ;
04190 ; With every call of this subroutine the blip cycle counter is initialized to
04191 ; the start of the DELAY phase (see subroutine UPDATTCOMP ($A7BF)).
04192 ;
04193 ; NOTE: The entry to this subroutine is in mid-code, not at the beginning.
04194 ;
04195 ; INPUT
04196 ;
04197 ; X = Offset into DRAWLINESTAB ($BAF9). Used values are:
04198 ; $00 -> Draw Attack Computer Display and cross hairs (Front view)
04199 ; $2A -> Draw Aft view cross hairs (Aft view)
04200 ; $31 -> Draw our starship's shape (Long-Range Scan view)
04201
A765 99A400 04202 LOOP028 STA DIRLEN,Y ; Store byte of 3-byte element
A768 E8 04203 INX ;
A769 88 04204 DEY ;
A76A 100E 04205 BPL SKIP048 ; Next byte of 3-byte element until 3 bytes copied
A76C 2082A7 04206 JSR DRAWLINE ; Draw line on PLAYFIELD
04207
A76F A905 04208 DRAWLINES LDA #5 ; Init blip cycle to DELAY phase...
A771 85A2 04209 STA BLIPCYCLECNT ; ...delays drawing each row
04210
A773 2C9509 04211 BIT GCSTATCOM ; Return if Attack Computer destroyed
A776 7009 04212 BVS SKIP049 ;
04213
A778 A002 04214 LDY #2 ;
A77A BDF9BA 04215 SKIP048 LDA DRAWLINESTAB,X ; Load byte of 3-byte element
A77D C9FE 04216 CMP #$FE ; Loop until end marker byte ($FE) encountered
A77F D0E4 04217 BNE LOOP028 ;
A781 60 04218 SKIP049 RTS ; Return
04219
04220 ;*******************************************************************************
04221 ;* *
04222 ;* DRAWLINE *
04223 ;* *
04224 ;* Draw a single horizontal or vertical line *
04225 ;* *
04226 ;*******************************************************************************
04227
04228 ; DESCRIPTION
04229 ;
04230 ; Draws a single horizontal or vertical transparent line.
04231 ;
04232 ; There are two entries to this subroutine:
04233 ;
04234 ; (1) DRAWLINE ($A782) is entered from subroutine DRAWLINES ($A76F) to draw a
04235 ; line in COLOR1.
04236 ;
04237 ; (2) DRAWLINE2 ($A784) is entered from subroutine UPDATTCOMP ($A7BF) to draw
04238 ; the blip in COLOR2 in the Attack Computer Display.
04239 ;
04240 ; The position, direction, and length of the line is defined by three bytes
04241 ; passed in memory addresses DIRLEN ($A4), PENROW ($A5), and PENCOLUMN ($A6).
04242 ;
04243 ; A drawing operation draws one transparent line. It uses both the color
04244 ; register number of the overwritten (old) and the overwriting (new) pixel to
04245 ; decide on the new pixel color register number. This results in a transparent
04246 ; drawing effect. See the table below for all resulting combinations of color
04247 ; registers.
04248 ;
04249 ; +-----------+---------------+
04250 ; | | Old Color |
04251 ; | | Register |
04252 ; | New Color +---------------+
04253 ; | Register | 0 | 1 | 2 | 3 |
04254 ; +-----------+---+---+---+---+
04255 ; | 0 | 0 | 1 | 2 | 3 |
04256 ; +-----------+---+---+---+---+
04257 ; | 1 | 1 | 1 | 3 | 3 |
04258 ; +-----------+---+---+---+---+
04259 ; | 2 | 2 | 3 | 2 | 3 |
04260 ; +-----------+---+---+---+---+
04261 ; | 3 | 3 | 3 | 3 | 3 |
04262 ; +-----------+---+---+---+---+
04263 ;
04264 ; For example, COLOR1 overwritten by COLOR2 yields COLOR3. If you look closely
04265 ; at the blip (in COLOR2) on the Attack Computer Display (in COLOR1) the lines
04266 ; of the Attack Computer Display shine through (in COLOR3) where they overlap.
04267 ;
04268 ; INPUT
04269 ;
04270 ; DIRLEN ($A4) = B7 = 0 -> Draw line to the right
04271 ; B7 = 1 -> Draw line downward
04272 ; B6..0 -> Length of line in pixels
04273 ; PENROW ($A5) = Start pixel row number of line
04274 ; PENCOLUMN ($A6) = Start pixel column number of line
04275
=006A 04276 L.PIXELBYTEOFF = $6A ; Within-row-offset to byte with pixel in PLAYFIELD
=006B 04277 L.BITPAT = $6B ; 1-byte bit pattern for 4 pixels of same color
=006E 04278 L.DIRSAV = $6E ; Saves DIRLEN
04279
A782 A955 04280 DRAWLINE LDA #$55 ; Copy 1-byte bit pattern for 4 pixels of COLOR1
A784 856B 04281 DRAWLINE2 STA L.BITPAT ;
A786 A5A4 04282 LDA DIRLEN ; Copy direction (and length) of line
A788 856E 04283 STA L.DIRSAV ;
A78A 297F 04284 AND #$7F ; Strip direction bit
A78C 85A4 04285 STA DIRLEN ; Store length of line
04286
A78E A4A5 04287 LOOP029 LDY PENROW ; Loop over length of line to be drawn
A790 B90008 04288 LDA PFMEMROWLO,Y ; Point MEMPTR to start of pen's pixel row...
A793 8568 04289 STA MEMPTR ; ...in PLAYFIELD memory
A795 B96408 04290 LDA PFMEMROWHI,Y ;
A798 8569 04291 STA MEMPTR+1 ;
04292
A79A A5A6 04293 LDA PENCOLUMN ; Calc and store pen's byte-within-row offset
A79C 4A 04294 LSR A ;
A79D 4A 04295 LSR A ;
A79E 856A 04296 STA L.PIXELBYTEOFF ;
04297
A7A0 A5A6 04298 LDA PENCOLUMN ; Calc pixel-within-byte index
A7A2 2903 04299 AND #$03 ;
A7A4 A8 04300 TAY ;
04301
A7A5 B9B0BA 04302 LDA PIXELMASKTAB,Y ; Pick mask to filter pixel in byte
A7A8 256B 04303 AND L.BITPAT ; ...AND with bit pattern for 4 pixels of same color
A7AA A46A 04304 LDY L.PIXELBYTEOFF ;
A7AC 1168 04305 ORA (MEMPTR),Y ; Blend byte with new pixel and PLAYFIELD byte
A7AE 9168 04306 STA (MEMPTR),Y ; ...and store it back in PLAYFIELD memory
04307
A7B0 246E 04308 BIT L.DIRSAV ; Check direction bit B7
A7B2 1004 04309 BPL SKIP050 ;
A7B4 E6A5 04310 INC PENROW ; If B7 = 1 -> Increment pen's pixel row number
A7B6 D002 04311 BNE SKIP051 ;
A7B8 E6A6 04312 SKIP050 INC PENCOLUMN ; If B7 = 0 -> Increment pen's pixel column number
04313
A7BA C6A4 04314 SKIP051 DEC DIRLEN ;
A7BC D0D0 04315 BNE LOOP029 ; Next pixel of line
A7BE 60 04316 RTS ; Return
04317
04318 ;*******************************************************************************
04319 ;* *
04320 ;* UPDATTCOMP *
04321 ;* *
04322 ;* Update Attack Computer Display *
04323 ;* *
04324 ;*******************************************************************************
04325
04326 ; DESCRIPTION
04327 ;
04328 ; Draws the blip of the tracked space object and the lock-on markers into the
04329 ; Attack Computer Display. The actual drawing follows a cycle of 11 game loop
04330 ; iterations (numbered by this subroutine as "blip cycles" 0..10), which can be
04331 ; divided into three phases:
04332 ;
04333 ; (1) Blip cycle 0..4: Draw blip shape row-by-row
04334 ;
04335 ; Draw the blip's shape into the Attack Computer Display, one row each blip
04336 ; cycle. After 5 blip cycles the blip shape is complete and completely
04337 ; visible because between blip cycles, that is, game loop iterations, the
04338 ; PLAYFIELD is not erased (only the PLAYFIELD space objects are). Drawing
04339 ; is executed by branching to entry DRAWLINE2 ($A784) of subroutine
04340 ; DRAWLINE ($A782). The blip shape is retrieved from table BLIPSHAPTAB
04341 ; ($BF6E).
04342 ;
04343 ; (2) Blip cycle 5..9: Delay
04344 ;
04345 ; Delay the execution of blip cycle 10.
04346 ;
04347 ; (3) Blip cycle 10: Update Attack Computer Display
04348 ;
04349 ; After verifying that the tracked space object is alive, calculate the
04350 ; blip's relative top-left pixel column and row number. The resulting
04351 ; values are in -11..11 and -6..4, relative to the blip's top-left
04352 ; reference position at pixel column number 131 and pixel row number 77,
04353 ; respectively.
04354 ;
04355 ; Filter the Attack Computer Display area: Only pixels of COLOR1 within the
04356 ; inner frame area (a 28 pixel wide x 15 pixel high rectangle with its
04357 ; top-left corner at pixel column number 120 and pixel row number 71) pass
04358 ; the filter operation. This effectively erases the blip.
04359 ;
04360 ; If the blip is within -2..+2 pixels off its horizontal reference position
04361 ; (pixel column numbers 129..132) then the tracked space object is in x
04362 ; lock-on. Draw the x lock-on marker.
04363 ;
04364 ; If the tracked space object is in x lock-on and the blip is within -2..+1
04365 ; pixels off its vertical reference position (pixel column numbers 75..78)
04366 ; then the tracked space object is in x and y lock-on. Draw also the y
04367 ; lock-on marker.
04368 ;
04369 ; If the tracked space object is in x and y lock-on and the tracked space
04370 ; object's z-coordinate < +3072 (+$0C**) <KM> then the tracked space object
04371 ; is in x, y and z lock-on. Draw also the z lock-on marker.
04372 ;
04373 ; If the tracked space object is in x, y, and z lock-on (and thus in
04374 ; optimal firing range) set the ISINLOCKON ($A3) flag.
04375 ;
04376 ; The following sketches show the Attack Computer Display area overlaid
04377 ; with the Attack Computer Display frame:
04378 ;
04379 ; 119 119
04380 ; 70 ############################## 70 ##############################
04381 ; # ....#.... # # # #
04382 ; # ....#.... # # # #
04383 ; # ....#.... # # # #
04384 ; # ....#.... # # # #
04385 ; # ############### # #......###############.......#
04386 ; #XXXX # ......... # XXXX# #......#.............#.......#
04387 ; # # ..$...... # # #......#....$........#.......#
04388 ; ######## ......... ######### ########.............#########
04389 ; # # ......... # # #......#.............#.......#
04390 ; # # ......... # # #YYYY..#.............#...YYYY#
04391 ; # ############### # #......###############.......#
04392 ; # ....#.... # #.............#..............#
04393 ; # ....#.... # # # #
04394 ; # ....#.... # # # #
04395 ; # ....#.... # # # #
04396 ; ############################## ##############################
04397 ;
04398 ; X = x lock-on marker Y = y lock-on marker
04399 ; . = x lock-on blip zone . = y lock-on blip zone
04400 ; $ = Blip's top-left reference $ = Blip's top-left reference
04401 ; position position
04402 ;
04403 ; 119
04404 ; 70 ##############################
04405 ; # # #
04406 ; # # #
04407 ; # # #
04408 ; # # #
04409 ; # ############### #
04410 ; # # # #
04411 ; # # $ # #
04412 ; ######## #########
04413 ; # # # #
04414 ; # # # #
04415 ; # ############### #
04416 ; # # #
04417 ; # # #
04418 ; # ZZ # ZZ #
04419 ; # ZZ # ZZ #
04420 ; ##############################
04421 ;
04422 ; Z = z lock-on marker
04423 ; $ = Blip's top-left reference
04424 ; position
04425
=006C 04426 L.SHIFTSHAP = $6C ; Saves shifted byte of blip shape bit pattern
04427
A7BF AE5C09 04428 UPDATTCOMP LDX TRACKDIGIT ; Load index of tracked space object
A7C2 A4A2 04429 LDY BLIPCYCLECNT ; Load blip cycle counter
A7C4 C005 04430 CPY #5 ;
A7C6 B024 04431 BCS SKIP054 ; Skip drawing blip if blip cycle > 5
04432
04433 ;*** Blip cycle 0..4: Draw blip shape one row each cycle ***********************
A7C8 A5A0 04434 LDA BLIPCOLUMN ; Init pen's pixel column number...
A7CA 85A6 04435 STA PENCOLUMN ; ...with top position of blip shape
A7CC B96EBF 04436 LDA BLIPSHAPTAB,Y ; Load bit pattern of one row of blip shape
A7CF 0A 04437 LOOP030 ASL A ; Shift bit pattern one position to the left
A7D0 856C 04438 STA L.SHIFTSHAP ; Temporarily save shifted shape byte
A7D2 900D 04439 BCC SKIP052 ; Skip if shifted-out bit = 0
04440
A7D4 A981 04441 LDA #$81 ; Store "draw a line of 1 pixel length downward"
A7D6 85A4 04442 STA DIRLEN ; ...for call to DRAWLINE2
04443
A7D8 A5A1 04444 LDA BLIPROW ; Init pen's pixel row number...
A7DA 85A5 04445 STA PENROW ; ...with leftmost position of blip shape
A7DC A9AA 04446 LDA #$AA ; Load 1-byte bit pattern for 4 pixels of COLOR2
A7DE 2084A7 04447 JSR DRAWLINE2 ; Draw pixel on PLAYFIELD
04448
A7E1 E6A6 04449 SKIP052 INC PENCOLUMN ; Move pen one pixel to the right
A7E3 A56C 04450 LDA L.SHIFTSHAP ; Reload shifted shape byte
A7E5 D0E8 04451 BNE LOOP030 ; Next horizontal pixel of blip shape
04452
A7E7 E6A1 04453 INC BLIPROW ; Move pen one pixel downward
A7E9 E6A2 04454 SKIP053 INC BLIPCYCLECNT ; Increment blip cycle counter
A7EB 60 04455 RTS ; Return
04456
04457 ;*** Blip cycle 5..9: Delay ****************************************************
A7EC C00A 04458 SKIP054 CPY #10 ; Return if blip cycle < 10
A7EE 90F9 04459 BCC SKIP053 ;
04460
04461 ;*** Blip cycle 10: Calculate new blip pixel row and column numbers ************
A7F0 B5E9 04462 LDA PL0LIFE,X ; Skip if tracked object not alive
A7F2 F03C 04463 BEQ SKIP059 ;
04464
A7F4 BD710A 04465 LDA XPOSHI,X ; Map x-coordinate of tracked space obj to -11..11:
A7F7 BCDE09 04466 LDY XPOSSIGN,X ; Skip if tracked object on left screen half (x >= 0)
A7FA F008 04467 BEQ SKIP055 ;
04468
A7FC C90C 04469 CMP #12 ; Skip if x of tracked obj < +$0C** (< 3327) <KM>
A7FE 900A 04470 BCC SKIP056 ;
A800 A90B 04471 LDA #11 ; Prep relative pixel column number of 11, skip
A802 1006 04472 BPL SKIP056 ;
04473
A804 C9F5 04474 SKIP055 CMP #-11 ; Skip if x of tracked obj >= -($0B**) (>=-2816) <KM>
A806 B002 04475 BCS SKIP056 ;
A808 A9F5 04476 LDA #-11 ; Prep relative pixel column number of -11
04477
A80A 18 04478 SKIP056 CLC ; Add 131 (= blip's top-left reference pixel column)
A80B 6983 04479 ADC #131 ;
A80D 85A0 04480 STA BLIPCOLUMN ; BLIPCOLUMN := 131 + -11..11
04481
A80F BDA20A 04482 LDA YPOSHI,X ; Map y-coordinate of tracked space obj to -6..4:
A812 49FF 04483 EOR #$FF ; Mirror y-coordinate on y-axis (displacement of +1)
A814 BC0F0A 04484 LDY YPOSSIGN,X ; Skip if tracked obj on lower screen half (y < 0)
A817 D008 04485 BNE SKIP057 ;
04486
A819 C905 04487 CMP #5 ; Skip if mirrored y of tracked obj < +$05** <KM>
A81B 900A 04488 BCC SKIP058 ;
A81D A904 04489 LDA #4 ; Prep relative pixel row number of 4, skip
A81F 1006 04490 BPL SKIP058 ;
04491
A821 C9FA 04492 SKIP057 CMP #-6 ; Skip if mirrored y of tracked obj >= -($06**) <KM>
A823 B002 04493 BCS SKIP058 ;
A825 A9FA 04494 LDA #-6 ; Prep relative pixel row number of -6
04495
A827 18 04496 SKIP058 CLC ; Add 77 (= blip's top-left ref. pixel row number)
A828 694D 04497 ADC #77 ;
A82A 85A1 04498 STA BLIPROW ; BLIPROW := 77 + -6..4
04499
A82C A900 04500 LDA #0 ; Reset blip cycle
A82E 85A2 04501 STA BLIPCYCLECNT ;
04502
04503 ;*** Filter Attack Computer Display frame area *********************************
04504 ; PLAYFIELD address of top-left of Attack Computer
=1B36 04505 PFMEM.C120R71 = PFMEM+71*40+120/4 ; Display's inner frame @ pixel column 120, row 71
04506
A830 A936 04507 SKIP059 LDA #<PFMEM.C120R71 ; Point MEMPTR to start of frame's...
A832 8568 04508 STA MEMPTR ; ...inner top-left corner at column 120, row 71...
A834 A91B 04509 LDA #>PFMEM.C120R71 ; ...in PLAYFIELD memory
A836 8569 04510 STA MEMPTR+1 ;
04511
A838 A20E 04512 LDX #14 ; Traverse a 28 x 15 pixel rect of PLAYFIELD memory
A83A A006 04513 LOOP031 LDY #6 ;
A83C B168 04514 LOOP032 LDA (MEMPTR),Y ; Load byte (4 pixels) from PLAYFIELD memory
A83E 2955 04515 AND #$55 ; Filter COLOR1 pixels
A840 9168 04516 STA (MEMPTR),Y ; Store byte (4 pixels) back to PLAYFIELD memory
A842 88 04517 DEY ;
A843 10F7 04518 BPL LOOP032 ; Next 4 pixels in x-direction
04519
A845 18 04520 CLC ; Add 40 to MEMPTR
A846 A568 04521 LDA MEMPTR ; (40 bytes = 160 pixels = 1 PLAYFIELD row of pixels)
A848 6928 04522 ADC #40 ;
A84A 8568 04523 STA MEMPTR ;
A84C 9002 04524 BCC SKIP060 ;
A84E E669 04525 INC MEMPTR+1 ;
04526
A850 CA 04527 SKIP060 DEX ;
A851 10E7 04528 BPL LOOP031 ; Next row of pixels in y-direction
04529
04530 ;*** Prepare lock-on marker checks *********************************************
A853 AE5C09 04531 LDX TRACKDIGIT ; Preload index of tracked space obj to check z-range
A856 C8 04532 INY ; Y := 0, preloaded value of ISINLOCKON
04533
04534 ;*** Draw lock-on markers ******************************************************
04535 ; PLAYFIELD addresses of
=1BFE 04536 PFMEM.C120R76 = PFMEM+76*40+120/4 ; ...x lock-on marker @ pixel column 120, row 76
=1C04 04537 PFMEM.C144R76 = PFMEM+76*40+144/4 ; ...x lock-on marker @ pixel column 144, row 76
=1C9E 04538 PFMEM.C120R80 = PFMEM+80*40+120/4 ; ...y lock-on marker @ pixel column 120, row 80
=1CA4 04539 PFMEM.C144R80 = PFMEM+80*40+144/4 ; ...y lock-on marker @ pixel column 144, row 80
=1D40 04540 PFMEM.C128R84 = PFMEM+84*40+128/4 ; ...z lock-on marker @ pixel column 128, row 84
=1D68 04541 PFMEM.C128R85 = PFMEM+85*40+128/4 ; ...z lock-on marker @ pixel column 128, row 85
=1D42 04542 PFMEM.C136R84 = PFMEM+84*40+136/4 ; ...z lock-on marker @ pixel column 136, row 84
=1D6A 04543 PFMEM.C136R85 = PFMEM+85*40+136/4 ; ...z lock-on marker @ pixel column 136, row 85
04544
A857 A588 04545 LDA LOCKONLIFE ; If lock-on lifetime expired redraw lock-on markers
A859 F004 04546 BEQ SKIP061 ;
04547
A85B C688 04548 DEC LOCKONLIFE ; else decrem. lock-on lifetime, skip drawing markers
A85D D039 04549 BNE SKIP062 ;
04550
A85F A5A0 04551 SKIP061 LDA BLIPCOLUMN ; Skip x, y, and z lock-on marker if blip's...
A861 C981 04552 CMP #129 ; ...top-left pixel column number not in 129..132
A863 9033 04553 BCC SKIP062 ;
A865 C985 04554 CMP #133 ;
A867 B02F 04555 BCS SKIP062 ;
04556
A869 A9AA 04557 LDA #$AA ; Draw x lock-on marker (4 horiz. pixels of COLOR2)
A86B 8DFE1B 04558 STA PFMEM.C120R76 ; ...at pixel column 120, row 76
A86E 8D041C 04559 STA PFMEM.C144R76 ; ...at pixel column 144, row 76
04560
A871 A5A1 04561 LDA BLIPROW ; Skip y and z lock-on marker if blip's...
A873 C94B 04562 CMP #75 ; ...top-left pixel row number not in 75...78
A875 9021 04563 BCC SKIP062 ;
A877 C94F 04564 CMP #79 ;
A879 B01D 04565 BCS SKIP062 ;
04566
A87B A9AA 04567 LDA #$AA ; Draw y lock-on marker (4 horiz. pixels of COLOR2)
A87D 8D9E1C 04568 STA PFMEM.C120R80 ; ...at pixel column 120, row 80
A880 8DA41C 04569 STA PFMEM.C144R80 ; ...at pixel column 144, row 80
04570
A883 BD400A 04571 LDA ZPOSHI,X ; Skip z lock-on marker if z >= +$0C** (>= 3072) <KM>
A886 C90C 04572 CMP #12 ;
A888 B00E 04573 BCS SKIP062 ;
04574
A88A A0A0 04575 LDY #$A0 ; Draw z lock-on marker (2 horiz. pixels of COLOR2)
A88C 8C401D 04576 STY PFMEM.C128R84 ; ...at pixel column 128, row 84 (prep lock-on flag)
A88F 8C681D 04577 STY PFMEM.C128R85 ; ...at pixel column 128, row 85
A892 8C421D 04578 STY PFMEM.C136R84 ; ...at pixel column 136, row 84
A895 8C6A1D 04579 STY PFMEM.C136R85 ; ...at pixel column 136, row 85
04580
A898 84A3 04581 SKIP062 STY ISINLOCKON ; Store lock-on flag (> 0 -> Tracked obj locked on)
A89A 60 04582 RTS ; Return
04583
04584 ;*******************************************************************************
04585 ;* *
04586 ;* HYPERWARP *
04587 ;* *
04588 ;* Handle hyperwarp *
04589 ;* *
04590 ;*******************************************************************************
04591
04592 ; DESCRIPTION
04593 ;
04594 ; Handles the hyperwarp sequence, which transports our starship from one sector
04595 ; to another. It can be divided into four phases:
04596 ;
04597 ; (1) ACCELERATION PHASE
04598 ;
04599 ; The ACCELERATION PHASE is entered after the hyperwarp sequence has been
04600 ; engaged in subroutine KEYBOARD ($AFFE) by pressing the 'H' key.
04601 ;
04602 ; The Hyperwarp Target Marker appears and our starship begins to
04603 ; accelerate. When our starship's velocity reaches 128 <KM/H> (the VELOCITY
04604 ; readout of the Control Panel Display displays "50"), the STAR TRAIL phase
04605 ; is entered.
04606 ;
04607 ; The Hyperwarp Target Marker is represented by a space object some fixed
04608 ; distance away in front of our starship as PLAYER3. It has a lifetime of
04609 ; 144 game loop iterations and is tracked. Thus, tracking handling in
04610 ; subroutine UPDATTCOMP ($A7BF) provides drawing the x and y lock-on
04611 ; markers in the Attack Computer Display when the Hyperwarp Target Marker
04612 ; is centered.
04613 ;
04614 ; A temporary arrival location on the Galactic Chart was saved when the
04615 ; hyperwarp was engaged in subroutine KEYBOARD ($AFFE). During the
04616 ; ACCELERATION PHASE (and the subsequent STAR TRAIL PHASE) this location is
04617 ; constantly updated depending on how much the Hyperwarp Target Marker
04618 ; veers off its center position.
04619 ;
04620 ; The actual arrival hyperwarp marker row and column numbers on the
04621 ; Galactic Chart are the sum of the temporary arrival hyperwarp marker row
04622 ; and column numbers stored when engaging the hyperwarp in subroutine
04623 ; KEYBOARD ($AFFE) and the number of Player/Missile (PM) pixels which the
04624 ; Hyperwarp Target Marker is off-center vertically and horizontally,
04625 ; respectively, at the end of the STAR TRAIL PHASE.
04626 ;
04627 ; NOTE: The used vertical center value of 119 PM pixels is the PM pixel row
04628 ; number of the top edge of the centered Hyperwarp Target Marker (from top
04629 ; to bottom: 8 PM pixels to the start of Display List + 16 PM pixels blank
04630 ; lines + 100 PM pixels to the vertical PLAYFIELD center - 5 PM pixels
04631 ; relative offset of the Hyperwarp Target Marker's shape center to the
04632 ; shape's top edge = 119 PM pixels). Recall also that PLAYERs at
04633 ; single-line resolution have PM pixels that are half as high as they are
04634 ; wide.
04635 ;
04636 ; NOTE: The used horizontal center value of 125 PM pixels is the PM pixel
04637 ; row number of the left edge of the centered Hyperwarp Target Marker (from
04638 ; left to right: 127 PM pixels to the PLAYFIELD center - 3 PM pixels
04639 ; relative offset of the Hyperwarp Target Marker's shape center to the
04640 ; shape's left edge = 125 PM pixels).
04641 ;
04642 ; If during the ACCELERATION PHASE (and the subsequent STAR TRAIL PHASE)
04643 ; you switch the Front view to another view, the Hyperwarp Target Marker
04644 ; changes to a random position which results in arriving at a random
04645 ; destination sector.
04646 ;
04647 ; During the ACCELERATION PHASE (and the subsequent STAR TRAIL PHASE) in
04648 ; all but NOVICE missions, the Hyperwarp Target Marker veers off with
04649 ; random velocity in x and y direction, which is changed during 6% of game
04650 ; loop iterations. Table VEERMASKTAB ($BED7) limits the maximum veer-off
04651 ; velocity depending on the mission level:
04652 ;
04653 ; +-----------+-----------------------------+
04654 ; | Mission | Veer-Off Velocity |
04655 ; +-----------+-----------------------------+
04656 ; | NOVICE | 0 <KM/H> |
04657 ; | PILOT | -63..-16, +16..+63 <KM/H> |
04658 ; | WARRIOR | -95..-16, +16..+95 <KM/H> |
04659 ; | COMMANDER | -127..-16, +16..+127 <KM/H> |
04660 ; +-----------+-----------------------------+
04661 ;
04662 ; (2) STAR TRAIL PHASE
04663 ;
04664 ; When our starship's velocity reaches a velocity of 128 <KM/H> (the
04665 ; VELOCITY readout of the Control Panel Display displays "50"), in addition
04666 ; to all effects of the ACCELERATION PHASE, multiple star trails begin to
04667 ; appear while our starship continues to accelerate. Each star trail is
04668 ; initialized in subroutine INITTRAIL ($A9B4).
04669 ;
04670 ; (3) HYPERSPACE PHASE
04671 ;
04672 ; When our starship's velocity reaches a velocity of 254 <KM/H> (the
04673 ; VELOCITY readout of the Control Panel Display displays "99") our starship
04674 ; enters the HYPERSPACE PHASE (the VELOCITY readout of the Control Panel
04675 ; Display displays the infinity symbol).
04676 ;
04677 ; During the first pass of the HYPERSPACE PHASE the hyperwarp state is set
04678 ; to HYPERSPACE. This makes the stars and the Hyperwarp Target Marker
04679 ; disappear in GAMELOOP ($A1F3). Then, the beeper sound pattern HYPERWARP
04680 ; TRANSIT is played in subroutine BEEP ($B3A6), the hyperwarp distance and
04681 ; required hyperwarp energy is calculated in subroutine CALCWARP ($B1A7),
04682 ; and the title line is preloaded with "HYPERSPACE". Code execution returns
04683 ; via calling subroutine CLEANUPWARP ($A98D) where game variables are
04684 ; already initialized to their post-hyperwarp values.
04685 ;
04686 ; During subsequent passes of the HYPERSPACE PHASE, the calculated
04687 ; hyperwarp energy is decremented in chunks of 10 energy units. Code
04688 ; execution returns via calling subroutine DECENERGY ($B86F), which
04689 ; decrements our starship's energy. After the calculated hyperwarp energy
04690 ; is spent the DECELERATION PHASE is entered.
04691 ;
04692 ; (4) DECELERATION PHASE
04693 ;
04694 ; The title line flashes "HYPERWARP COMPLETE", the star field reappears and
04695 ; our starship decelerates to a stop. The Engines and the hyperwarp are
04696 ; disengaged and stopped in subroutine ENDWARP ($A987), the arrival
04697 ; coordinates on the Galactic Chart are initialized, as well as the
04698 ; vicinity mask.
04699 ;
04700 ; The vicinity mask limits the position vector components (coordinates) of
04701 ; space objects in the arrival sector relative to our starship. The
04702 ; vicinity mask is picked from table VICINITYMASKTAB ($BFB3) by an index
04703 ; calculated by the arrival y-coordinate modulo 8: The more you have placed
04704 ; the arrival hyperwarp marker in the vertical center of a sector on the
04705 ; Galactic Chart, the closer space objects in this sector will be to our
04706 ; starship. For example, if you placed the arrival hyperwarp marker exactly
04707 ; in the vertical middle of the sector the index will be 3, thus the space
04708 ; objects inside the arrival sector will be in the vicinity of <= 4095 <KM>
04709 ; of our starship. The following table lists the possible coordinates
04710 ; depending on the calculated index:
04711 ;
04712 ; +-------+-----------------------+
04713 ; | Index | ABS(Coordinate) |
04714 ; +-------+-----------------------+
04715 ; | 0 | <= 65535 ($FF**) <KM> |
04716 ; | 1 | <= 65535 ($FF**) <KM> |
04717 ; | 2 | <= 16383 ($3F**) <KM> |
04718 ; | 3 | <= 4095 ($0F**) <KM> |
04719 ; | 4 | <= 16383 ($3F**) <KM> |
04720 ; | 5 | <= 32767 ($7F**) <KM> |
04721 ; | 6 | <= 65535 ($FF**) <KM> |
04722 ; | 7 | <= 65535 ($FF**) <KM> |
04723 ; +-------+-----------------------+
04724 ;
04725 ; If there is a starbase in the arrival sector, its x and y coordinates are
04726 ; initialized to random values within the interval defined by the vicinity
04727 ; mask by using subroutine RNDINVXY ($B7BE). Its z-coordinate is forced to
04728 ; a value >= +$71** (+28928) <KM>. Its velocity vector components are set
04729 ; to 0 <KM/H>.
04730 ;
04731 ; If there are Zylon ships in the arrival sector then a red alert is
04732 ; initialized by setting the red alert lifetime to 255 game loop
04733 ; iterations, playing the beeper sound pattern RED ALERT in subroutine BEEP
04734 ; ($B3A6) and setting the title phrase to "RED ALERT".
04735
A89B A4C0 04736 HYPERWARP LDY WARPSTATE ; Return if hyperwarp not engaged
A89D F061 04737 BEQ SKIP066 ;
04738
A89F A570 04739 LDA VELOCITYLO ; If velocity >= 254 <KM/H> skip to HYPERSPACE PHASE
A8A1 C9FE 04740 CMP #254 ;
A8A3 B05C 04741 BCS SKIP067 ;
04742
A8A5 C980 04743 CMP #128 ; If velocity < 128 <KM/H> skip to ACCELERATION PHASE
A8A7 9003 04744 BCC SKIP063 ;
04745
04746 ;*** STAR TRAIL PHASE **********************************************************
A8A9 20B4A9 04747 JSR INITTRAIL ; Init star trail
04748
04749 ;*** ACCELERATION PHASE ********************************************************
A8AC A903 04750 SKIP063 LDA #3 ; Track Hyperwarp Target Marker (PLAYER3)
A8AE 8D5C09 04751 STA TRACKDIGIT ;
04752
A8B1 A990 04753 LDA #SHAP.HYPERWARP ; PLAYER3 is HYPERWARP TARGET MARKER (shape type 9)
A8B3 8D8F0C 04754 STA PL3SHAPTYPE ;
A8B6 85EC 04755 STA PL3LIFE ; PLAYER3 lifetime := 144 game loops
04756
A8B8 A91F 04757 LDA #$1F ; PLAYER3 z-coordinate := $1F** (7936..8191) <KM>
A8BA 8D430A 04758 STA PL3ZPOSHI ;
04759
A8BD 38 04760 SEC ; New arrival hyperwarp marker row number is...
A8BE ADFC0B 04761 LDA PL3ROWNEW ; WARPARRVROW := WARPTEMPROW + PL3ROWNEW...
A8C1 E977 04762 SBC #119 ; ... - 119 PM pixels (top edge of centered...
A8C3 18 04763 CLC ; ...Hyperwarp Target Marker)
A8C4 65C5 04764 ADC WARPTEMPROW ;
A8C6 297F 04765 AND #$7F ; Limit WARPARRVROW to 0..127
A8C8 858E 04766 STA WARPARRVROW ;
04767
A8CA 38 04768 SEC ; New arrival hyperwarp marker column number is...
A8CB AD2D0C 04769 LDA PL3COLUMN ; WARPARRVCOLUMN := WARPTEMPCOLUMN + PL3COLUMN...
A8CE E97D 04770 SBC #125 ; ... - 125 PM pixels (left edge of centered...
A8D0 18 04771 CLC ; ...Hyperwarp Target Marker)
A8D1 65C4 04772 ADC WARPTEMPCOLUMN ;
A8D3 297F 04773 AND #$7F ; Limit WARPARRVCOLUMN to 0..127
A8D5 858F 04774 STA WARPARRVCOLUMN ;
04775
A8D7 A562 04776 LDA MISSIONLEVEL ; Skip if NOVICE mission
A8D9 F011 04777 BEQ SKIP065 ;
04778
A8DB AD0AD2 04779 LDA RANDOM ; Prep random number
A8DE A4D0 04780 LDY SHIPVIEW ; Skip if in Front view
A8E0 F006 04781 BEQ SKIP064 ;
04782
A8E2 8D2D0C 04783 STA PL3COLUMN ; Randomize PM pixel row and column number...
A8E5 8DFC0B 04784 STA PL3ROWNEW ; ...of Hyperwarp Target Marker
04785
A8E8 C910 04786 SKIP064 CMP #16 ; Return in 94% (240:256) of game loops
A8EA B014 04787 BCS SKIP066 ;
04788
04789 ;*** Veer off Hyperwarp Target Marker and return *******************************
A8EC AD0AD2 04790 SKIP065 LDA RANDOM ; Prep random x-velocity of Hyperwarp Target Marker
A8EF 0910 04791 ORA #$10 ; Velocity value >= 16 <KM/H>
A8F1 25C6 04792 AND VEERMASK ; Limit velocity value by mission level
A8F3 8D9A0B 04793 STA PL3XVEL ; PLAYER3 x-velocity := velocity value
04794
A8F6 AD0AD2 04795 LDA RANDOM ; Prep random y-velocity of Hyperwarp Target Marker
A8F9 0910 04796 ORA #$10 ; Velocity value >= 16 <KM/H>
A8FB 25C6 04797 AND VEERMASK ; Limit velocity value by mission level
A8FD 8DCB0B 04798 STA PL3YVEL ; PLAYER3 y-velocity := velocity value
A900 60 04799 SKIP066 RTS ; Return
04800
04801 ;*** HYPERSPACE PHASE **********************************************************
A901 98 04802 SKIP067 TYA ; Skip if already in HYPERSPACE PHASE
A902 3011 04803 BMI SKIP068 ;
04804
04805 ;*** HYPERSPACE PHASE (First pass) *********************************************
A904 A9FF 04806 LDA #$FF ; Set hyperwarp state to HYPERSPACE PHASE
A906 85C0 04807 STA WARPSTATE ;
04808
A908 A200 04809 LDX #$00 ; Play beeper sound pattern HYPERWARP TRANSIT
A90A 20A6B3 04810 JSR BEEP ;
04811
A90D 20A7B1 04812 JSR CALCWARP ; Calc hyperwarp energy
04813
A910 A01B 04814 LDY #$1B ; Prep title phrase "HYPERSPACE"
A912 4C8DA9 04815 JMP CLEANUPWARP ; Return via CLEANUPWARP
04816
04817 ;*** HYPERSPACE PHASE (Second and later passes) ********************************
A915 C691 04818 SKIP068 DEC WARPENERGY ; Decrement energy in chunks of 10 energy units
A917 F005 04819 BEQ SKIP069 ; Skip to DECELERATION PHASE if hyperwarp energy zero
04820
A919 A202 04821 LDX #2 ; ENERGY := ENERGY - 10 and return
A91B 4C6FB8 04822 JMP DECENERGY ;
04823
04824 ;*** DECELERATION PHASE ********************************************************
A91E A019 04825 SKIP069 LDY #$19 ; Prep title phrase "HYPERWARP COMPLETE"
A920 2087A9 04826 JSR ENDWARP ; Stop our starship
04827
A923 A58F 04828 LDA WARPARRVCOLUMN ; Make the arrival hyperwarp marker column number...
A925 858D 04829 STA WARPDEPRCOLUMN ; ...the departure hyperwarp marker column number
A927 A58E 04830 LDA WARPARRVROW ; Make the arrival hyperwarp marker row number...
A929 858C 04831 STA WARPDEPRROW ; ...the departure hyperwarp marker row number
04832
A92B 4A 04833 LSR A ; B3..1 of arrival hyperwarp marker row number...
A92C 2907 04834 AND #$07 ; ...pick vicinity mask
A92E AA 04835 TAX ;
A92F BDB3BF 04836 LDA VICINITYMASKTAB,X ;
A932 85C7 04837 STA VICINITYMASK ; Store vicinity mask (limits space obj coordinates)
04838
A934 A492 04839 LDY ARRVSECTOR ; Make the arrival sector the current sector
A936 8490 04840 STY CURRSECTOR ;
04841
04842 ;*** Init starbase in arrival sector *******************************************
A938 A900 04843 LDA #0 ; Clear starbase-in-sector flag
A93A 857B 04844 STA ISSTARBASESECT ;
04845
A93C BEC908 04846 LDX GCMEMMAP,Y ; Skip if no starbase in arrival sector
A93F 102E 04847 BPL SKIP070 ;
04848
A941 A9FF 04849 LDA #$FF ; Set starbase-in-sector flag
A943 857B 04850 STA ISSTARBASESECT ;
04851
04852 ;*** Set position vector and velocity vector of starbase ***********************
A945 A000 04853 LDY #0 ;
A947 A900 04854 LOOP033 LDA #0 ; Loop over all coordinates of starbase
A949 99680B 04855 STA PL2ZVEL,Y ; Starbase velocity vector component := 0 <KM/H>
A94C A901 04856 LDA #1 ;
A94E 99AF09 04857 STA PL2ZPOSSIGN,Y ; Starbase coordinate sign := + (positive)
A951 AD0AD2 04858 LDA RANDOM ; Prep random number...
A954 25C7 04859 AND VICINITYMASK ; ...limit number range by vicinity mask, then...
A956 99420A 04860 STA PL2ZPOSHI,Y ; ...store in starbase coordinate (high byte)
04861
A959 98 04862 TYA ;
A95A 18 04863 CLC ;
A95B 6931 04864 ADC #NUMSPCOBJ.ALL ;
A95D A8 04865 TAY ;
A95E C993 04866 CMP #NUMSPCOBJ.ALL*3 ;
A960 90E5 04867 BCC LOOP033 ; Next starbase coordinate
04868
A962 AD420A 04869 LDA PL2ZPOSHI ; Force starbase z-coordinate >= +$71** <KM>
A965 0971 04870 ORA #$71 ;
A967 8D420A 04871 STA PL2ZPOSHI ;
A96A A202 04872 LDX #2 ; Randomly invert starbase x and y coordinates...
A96C 4CBEB7 04873 JMP RNDINVXY ; ...and return
04874
04875 ;*** Flash red alert if Zylon sector entered ***********************************
A96F F00E 04876 SKIP070 BEQ SKIP071 ; Skip if no Zylon ships in sector
04877
A971 A9FF 04878 LDA #255 ; Red alert lifetime := 255 game loops
A973 858B 04879 STA REDALERTLIFE ;
04880
A975 A206 04881 LDX #$06 ; Play beeper sound pattern RED ALERT
A977 20A6B3 04882 JSR BEEP ;
04883
A97A A075 04884 LDY #$75 ; Set title phrase "RED ALERT"
A97C 2023B2 04885 JSR SETTITLE ;
04886
A97F 60 04887 SKIP071 RTS ; Return
04888
04889 ;*******************************************************************************
04890 ;* *
04891 ;* ABORTWARP *
04892 ;* *
04893 ;* Abort hyperwarp *
04894 ;* *
04895 ;*******************************************************************************
04896
04897 ; DESCRIPTION
04898 ;
04899 ; Aborts hyperwarp.
04900 ;
04901 ; This subroutine is entered from subroutine KEYBOARD ($AFFE). It subtracts 100
04902 ; energy units for aborting the hyperwarp and preloads the title phrase with
04903 ; "HYPERWARP ABORTED". Code execution continues into subroutine ENDWARP
04904 ; ($A987).
04905
A980 A201 04906 ABORTWARP LDX #1 ; ENERGY := ENERGY - 100 after hyperwarp abort
A982 206FB8 04907 JSR DECENERGY ;
04908
A985 A017 04909 LDY #$17 ; Prep title phrase "HYPERWARP ABORTED"
04910
04911 ;*******************************************************************************
04912 ;* *
04913 ;* ENDWARP *
04914 ;* *
04915 ;* End hyperwarp *
04916 ;* *
04917 ;*******************************************************************************
04918
04919 ; DESCRIPTION
04920 ;
04921 ; Ends hyperwarp.
04922 ;
04923 ; This subroutine stops our starship's Engines and resets the hyperwarp state.
04924 ; Code execution continues into subroutine CLEANUPWARP ($A98D).
04925
A987 A900 04926 ENDWARP LDA #0 ; Stop Engines
A989 8571 04927 STA NEWVELOCITY ;
A98B 85C0 04928 STA WARPSTATE ; Disengage hyperwarp
04929
04930 ;*******************************************************************************
04931 ;* *
04932 ;* CLEANUPWARP *
04933 ;* *
04934 ;* Clean up hyperwarp variables *
04935 ;* *
04936 ;*******************************************************************************
04937
04938 ; DESCRIPTION
04939 ;
04940 ; Cleans up after a hyperwarp.
04941 ;
04942 ; This subroutine restores many hyperwarp related variables to their
04943 ; post-hyperwarp values: The number of used space objects is set to the regular
04944 ; value of 16 (5 PLAYER space objects + 12 PLAYFIELD space objects (stars),
04945 ; counted 0..16), our starship's velocity (high byte) is cleared as well as the
04946 ; explosion lifetime, the hit badness, the PLAYER3 shape type (Hyperwarp Target
04947 ; Marker), the Engines energy drain rate, and the lifetimes of the PLAYERs. The
04948 ; docking state is reset as well as the tracking digit. The title phrase is
04949 ; updated with either "HYPERSPACE" or "HYPERWARP ABORTED".
04950 ;
04951 ; INPUT
04952 ;
04953 ; Y = Title phrase offset. Used values are:
04954 ; $17 -> "HYPERWARP ABORTED"
04955 ; $1B -> "HYPERSPACE"
04956
A98D A910 04957 CLEANUPWARP LDA #NUMSPCOBJ.NORM-1 ; Set normal number of space objects
A98F 8579 04958 STA MAXSPCOBJIND ; (5 PLAYER spc objs + 12 PLAYFIELD spc objs (stars))
04959
A991 A900 04960 LDA #0 ;
A993 85C1 04961 STA VELOCITYHI ; Turn off hyperwarp velocity
A995 8573 04962 STA EXPLLIFE ; Explosion lifetime := 0 game loops
A997 858A 04963 STA HITBADNESS ; HITBADNESS := NO HIT
A999 8D8F0C 04964 STA PL3SHAPTYPE ; Clear PLAYER3 shape type
A99C 8580 04965 STA DRAINENGINES ; Clear Engines energy drain rate
A99E C017 04966 CPY #$17 ; Skip if hyperwarp was aborted
A9A0 F004 04967 BEQ SKIP072 ;
04968
A9A2 85E9 04969 STA PL0LIFE ; Zylon ship 0 lifetime := 0 game loops
A9A4 85EA 04970 STA PL1LIFE ; Zylon ship 1 lifetime := 0 game loops
04971
A9A6 85EB 04972 SKIP072 STA PL2LIFE ; Zylon photon torpedo lifetime := 0 game loops
A9A8 85EC 04973 STA PL3LIFE ; Hyperwarp Target Marker lifetime := 0 game loops
A9AA 85ED 04974 STA PL4LIFE ; Photon torpedo 1 lifetime := 0 game loops
A9AC 8575 04975 STA DOCKSTATE ; DOCKSTATE := NO DOCKING
A9AE 8D5C09 04976 STA TRACKDIGIT ; Clear index of tracked space object
A9B1 4C23B2 04977 JMP SETTITLE ; Set title phrase and return
04978
04979 ;*******************************************************************************
04980 ;* *
04981 ;* INITTRAIL *
04982 ;* *
04983 ;* Initialize star trail during STAR TRAIL PHASE of hyperwarp *
04984 ;* *
04985 ;*******************************************************************************
04986
04987 ; DESCRIPTION
04988 ;
04989 ; BACKGROUND
04990 ;
04991 ; Star trails are displayed during the STAR TRAIL PHASE, that is, after the
04992 ; ACCELERATION PHASE and before the HYPERSPACE PHASE of the hyperwarp.
04993 ;
04994 ; A star trail is formed by 6 stars represented by 6 PLAYFIELD space objects
04995 ; with continuous position vector indices in 17..48 (indices are wrapped around
04996 ; when greater than 48). Between the creations of two star trails there is delay
04997 ; of 4 game loop iterations.
04998 ;
04999 ; DETAILS
05000 ;
05001 ; This subroutine first decrements this star trail creation delay, returning if
05002 ; the delay is still counting down. If the delay falls below 0 then it continues
05003 ; accelerating our starship's velocity toward hyperwarp speed and then creates a
05004 ; new star trail:
05005 ;
05006 ; First, it raises the maximum index of used space objects to 48 (increasing the
05007 ; number of displayed space objects to 49), resets the star trail creation delay
05008 ; to 4 game loop iterations, and then forms a new star trail of 6 stars
05009 ; represented by 6 PLAYFIELD space objects. The x and y coordinates for all 6
05010 ; stars are the same, picked randomly from tables WARPSTARXTAB ($BB3A) and
05011 ; WARPSTARYTAB ($BB3E), respectively, with their signs changed randomly. Their
05012 ; z-coordinates are computed in increasing depth from at least +4608 (+$12**)
05013 ; <KM> in intervals of +80 (+$0050) <KM>. Their velocity vector components are
05014 ; set to 0 <KM/H>.
05015
=0068 05016 L.RANGE = $68 ; z-coordinate of star in star trail (16-bit value)
=006E 05017 L.TRAILCNT = $6E ; Star's index in star trail. Used values are: 0..5.
05018
A9B4 C6C2 05019 INITTRAIL DEC TRAILDELAY ; Decrement star trail delay
A9B6 1068 05020 BPL SKIP074 ; Return if delay still counting
05021
A9B8 A901 05022 LDA #1 ; Turn on hyperwarp velocity
A9BA 85C1 05023 STA VELOCITYHI ;
05024
A9BC A930 05025 LDA #NUMSPCOBJ.ALL-1 ; Max index of space objects (for star trail stars)
A9BE 8579 05026 STA MAXSPCOBJIND ;
05027
A9C0 A903 05028 LDA #3 ; Star trail delay := 3(+1) game loops
A9C2 85C2 05029 STA TRAILDELAY ;
05030
A9C4 A6C3 05031 LDX TRAILIND ; Next avail. space obj index for star of star trail
05032
A9C6 A912 05033 LDA #$12 ; Star z-coordinate := >= +$12** (+4608) <KM>
A9C8 8569 05034 STA L.RANGE+1 ;
05035
A9CA AD0AD2 05036 LDA RANDOM ; Calc random index to pick initial star coordinates
A9CD 2903 05037 AND #$03 ;
A9CF A8 05038 TAY ;
A9D0 B93ABB 05039 LDA WARPSTARXTAB,Y ; Pick x-coordinate (high byte) of star from table
A9D3 9D710A 05040 STA XPOSHI,X ;
A9D6 B93EBB 05041 LDA WARPSTARYTAB,Y ;
A9D9 9DA20A 05042 STA YPOSHI,X ; Pick y-coordinate (high byte) of star from table
A9DC 20BEB7 05043 JSR RNDINVXY ; Randomize signs of x and y coordinates of star
05044
A9DF 8A 05045 TXA ; Save space object index
A9E0 A8 05046 TAY ;
A9E1 A905 05047 LDA #5 ; Loop over 5(+1) stars that form the star trail
A9E3 856E 05048 STA L.TRAILCNT ; Store star counter of star trail
05049
A9E5 18 05050 LOOP034 CLC ; Place stars in z-coordinate intervals of +80 <KM>
A9E6 A568 05051 LDA L.RANGE ;
A9E8 6950 05052 ADC #80 ;
A9EA 8568 05053 STA L.RANGE ;
A9EC 9DD30A 05054 STA ZPOSLO,X ;
A9EF A569 05055 LDA L.RANGE+1 ;
A9F1 6900 05056 ADC #0 ;
A9F3 8569 05057 STA L.RANGE+1 ;
A9F5 9D400A 05058 STA ZPOSHI,X ;
05059
A9F8 A900 05060 LDA #0 ; Star's velocity vector components := 0 <KM/H>
A9FA 9D660B 05061 STA ZVEL,X ;
A9FD 9D970B 05062 STA XVEL,X ;
AA00 9DC80B 05063 STA YVEL,X ;
AA03 A901 05064 LDA #1 ; Star's z-coordinate sign := + (= ahead of starship)
AA05 9DAD09 05065 STA ZPOSSIGN,X ;
05066
AA08 A963 05067 LDA #99 ; Init pixel row and column numbers to magic...
AA0A 9DF90B 05068 STA PIXELROWNEW,X ; ...offscreen value (triggers automatic recalc in...
AA0D 9D2A0C 05069 STA PIXELCOLUMN,X ; ...GAMELOOP's calls to SCREENCOLUMN and SCREENROW)
05070
AA10 20C1AC 05071 JSR COPYPOSXY ; Copy x and y coordinate from previous star in trail
05072
AA13 CA 05073 DEX ; Decrement space object index to next star
AA14 E011 05074 CPX #NUMSPCOBJ.NORM ; If index reaches minimum value...
AA16 B002 05075 BCS SKIP073 ;
AA18 A230 05076 LDX #NUMSPCOBJ.ALL-1 ; ...wrap-around to maximum space object index
AA1A C66E 05077 SKIP073 DEC L.TRAILCNT ;
AA1C 10C7 05078 BPL LOOP034 ; Next star of star trail
05079
AA1E 86C3 05080 STX TRAILIND ; Save space object index of star trail's last star
AA20 60 05081 SKIP074 RTS ; Return
05082
05083 ;*******************************************************************************
05084 ;* *
05085 ;* PROJECTION *
05086 ;* *
05087 ;* Calculate pixel column (or row) number from position vector *
05088 ;* *
05089 ;*******************************************************************************
05090
05091 ; Calculates the pixel column (or row) number of a position vector x (or y)
05092 ; component relative to the PLAYFIELD center by computing the perspective
05093 ; projection quotient
05094 ;
05095 ; QUOTIENT := DIVIDEND / DIVISOR * 128
05096 ;
05097 ; with
05098 ;
05099 ; DIVIDEND := ABS(x-coordinate (or y-coordinate)) / 2
05100 ; DIVISOR := ABS(z-coordinate) / 2
05101 ;
05102 ; If the QUOTIENT is in 0..255, it is used as an index to pick the pixel column
05103 ; (or row) number from table MAPTO80 ($0DE9), returning values in 0..80.
05104 ;
05105 ; If the QUOTIENT is larger than 255 ("dividend overflow") or if the
05106 ; z-coordinate = 0 ("division by zero") then the error value 255 is returned.
05107 ;
05108 ; INPUT
05109 ;
05110 ; X = Position vector index. Used values are: 0..48.
05111 ; DIVIDEND ($6A..$6B) = Dividend (positive 16-bit value), contains the
05112 ; absolute value of the x (or y) coordinate.
05113 ;
05114 ; OUTPUT
05115 ;
05116 ; A = Pixel column (or row) number relative to PLAYFIELD center. Used values
05117 ; are:
05118 ; 0..80 -> Pixel number
05119 ; 255 -> Error value indicating "dividend overflow" or "division by zero"
05120
=0068 05121 L.DIVISOR = $68 ; Divisor (16-bit value)
=006D 05122 L.QUOTIENT = $6D ; Division result (unsigned 8-bit value)
=006E 05123 L.LOOPCNT = $6E ; Division loop counter. Used values are: 7..0.
05124
AA21 A900 05125 PROJECTION LDA #0 ; Init quotient result
AA23 856D 05126 STA L.QUOTIENT ;
05127
AA25 A907 05128 LDA #7 ; Init division loop counter
AA27 856E 05129 STA L.LOOPCNT ;
05130
AA29 466B 05131 LSR DIVIDEND+1 ; DIVIDEND := x-coordinate (or y-coordinate) / 2
AA2B 666A 05132 ROR DIVIDEND ; (division by 2 to make B15 = 0?) (?)
05133
AA2D A5D0 05134 LDA SHIPVIEW ; Skip if in Aft view
AA2F D00F 05135 BNE SKIP075 ;
05136
AA31 BD400A 05137 LDA ZPOSHI,X ; If in Front view -> DIVISOR := z-coordinate / 2
AA34 4A 05138 LSR A ; (division by 2 to make B15 = 0?) (?)
AA35 8569 05139 STA L.DIVISOR+1 ;
AA37 BDD30A 05140 LDA ZPOSLO,X ;
AA3A 6A 05141 ROR A ;
AA3B 8568 05142 STA L.DIVISOR ;
AA3D 4C52AA 05143 JMP LOOP035 ;
05144
AA40 38 05145 SKIP075 SEC ; If in Aft view -> DIVISOR := - z-coordinate / 2
AA41 A900 05146 LDA #0 ; (division by 2 to make B15 = 0?) (?)
AA43 FDD30A 05147 SBC ZPOSLO,X ;
AA46 8568 05148 STA L.DIVISOR ;
AA48 A900 05149 LDA #0 ;
AA4A FD400A 05150 SBC ZPOSHI,X ;
AA4D 4A 05151 LSR A ;
AA4E 8569 05152 STA L.DIVISOR+1 ;
AA50 6668 05153 ROR L.DIVISOR ;
05154
AA52 066D 05155 LOOP035 ASL L.QUOTIENT ; QUOTIENT := DIVIDEND / DIVISOR * 128
AA54 38 05156 SEC ;
AA55 A56A 05157 LDA DIVIDEND ;
AA57 E568 05158 SBC L.DIVISOR ;
AA59 A8 05159 TAY ;
AA5A A56B 05160 LDA DIVIDEND+1 ;
AA5C E569 05161 SBC L.DIVISOR+1 ;
AA5E 9006 05162 BCC SKIP076 ;
05163
AA60 856B 05164 STA DIVIDEND+1 ;
AA62 846A 05165 STY DIVIDEND ;
AA64 E66D 05166 INC L.QUOTIENT ;
05167
AA66 066A 05168 SKIP076 ASL DIVIDEND ;
AA68 266B 05169 ROL DIVIDEND+1 ;
AA6A 9003 05170 BCC SKIP077 ;
05171
AA6C A9FF 05172 LDA #255 ; Return 255 if division by zero or dividend overflow
AA6E 60 05173 RTS ;
05174
AA6F C66E 05175 SKIP077 DEC L.LOOPCNT ;
AA71 10DF 05176 BPL LOOP035 ; Next division loop iteration
05177
AA73 A46D 05178 LDY L.QUOTIENT ; Prep with quotient
AA75 B9E90D 05179 LDA MAPTO80,Y ; Pick and return pixel column (or row) number...
AA78 60 05180 SKIP078 RTS ; ...relative to PLAYFIELD center
05181
05182 ;*******************************************************************************
05183 ;* *
05184 ;* MANEUVER *
05185 ;* *
05186 ;* Maneuver our starship's and Zylon photon torpedoes and Zylon ships *
05187 ;* *
05188 ;*******************************************************************************
05189
05190 ; DESCRIPTION
05191 ;
05192 ; This subroutine maneuvers both of our starship's photon torpedoes, the single
05193 ; Zylon photon torpedo, and the one or two Zylon ships that are simultaneously
05194 ; displayed on the screen. It also creates meteors and new Zylon ships. This
05195 ; subroutine is executed only if our starship is not in a starbase sector and
05196 ; hyperwarp is not engaged.
05197 ;
05198 ; BACKGROUND
05199 ;
05200 ; When a Zylon ship is initialized, a "flight pattern" is assigned to it. There
05201 ; are 3 flight patterns (0, 1, and 4) which are picked from table ZYLONFLPATTAB
05202 ; ($BF91).
05203 ;
05204 ; The flight pattern determines the maximum velocity with which a Zylon ship can
05205 ; move along each axis of the 3D coordinate system, that is, the maximum value
05206 ; of a velocity vector component. Velocity vector components for Zylon ships are
05207 ; picked from the Zylon velocity table ZYLONVELTAB ($BF99):
05208 ;
05209 ; +-----------------+-----+-----+-----+-----+-----+-----+-----+-----+
05210 ; | Velocity Index | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
05211 ; +-----------------+-----+-----+-----+-----+-----+-----+-----+-----+
05212 ; | Velocity <KM/H> | +62 | +30 | +16 | +8 | +4 | +2 | +1 | 0 |
05213 ; +-----------------+-----+-----+-----+-----+-----+-----+-----+-----+
05214 ; +-----------------+-----+-----+-----+-----+-----+-----+-----+-----+
05215 ; | Velocity Index | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 |
05216 ; +-----------------+-----+-----+-----+-----+-----+-----+-----+-----+
05217 ; | Velocity <KM/H> | 0 | -1 | -2 | -4 | -8 | -16 | -30 | -62 |
05218 ; +-----------------+-----+-----+-----+-----+-----+-----+-----+-----+
05219 ;
05220 ; The index into the Zylon velocity table ZYLONVELTAB ($BF99) corresponding to
05221 ; the maximum velocity is called the "maximum velocity index". The following
05222 ; table shows the flight patterns, their maximum velocity indices, and their
05223 ; corresponding velocities:
05224 ;
05225 ; +----------------+------------------+------------------+
05226 ; | Flight Pattern | Maximum Velocity | Maximum Velocity |
05227 ; | | Index | |
05228 ; +----------------+------------------+------------------+
05229 ; | 0 | 0 | +62 <KM/H> |
05230 ; | 0 | 15 | -62 <KM/H> |
05231 ; | 1 | 1 | +30 <KM/H> |
05232 ; | 1 | 14 | -30 <KM/H> |
05233 ; | 4 | 4 | +4 <KM/H> |
05234 ; | 4 | 11 | -4 <KM/H> |
05235 ; +----------------+------------------+------------------+
05236 ;
05237 ; Because flight pattern 0 produces the fastest-moving Zylon ships, which
05238 ; maneuver aggressively, it is called the "attack flight pattern".
05239 ;
05240 ; Each Zylon ship has a set of 3 maximum velocity indices, one for each of its
05241 ; velocity vector components.
05242 ;
05243 ; Each Zylon ship has also one more set of 3 velocity indices, called "Zylon
05244 ; velocity indices", one for each of its velocity vector components. They are
05245 ; used to pick the current values of the velocity vector components from the
05246 ; Zylon velocity table ZYLONVELTAB ($BF99).
05247 ;
05248 ; In order to maneuver Zylon ships this subroutine uses the concept of
05249 ; "milestone velocity indices". By using delay timers, called "Zylon timers",
05250 ; this subroutine gradually increases or decreases the Zylon velocity indices
05251 ; with every game loop iteration to eventually match the corresponding milestone
05252 ; velocity indices. By incrementing a Zylon velocity index a Zylon ship
05253 ; accelerates toward the negative direction of a coordinate axis. By
05254 ; decrementing a Zylon velocity index a Zylon ship accelerates toward the
05255 ; positive direction of a coordinate axis. If one milestone velocity index is
05256 ; matched or a "milestone timer" has counted down to 0, a new milestone velocity
05257 ; index is calculated and the matching of the current Zylon velocity indices
05258 ; with the new milestone velocity indices repeats.
05259 ;
05260 ; DETAILS
05261 ;
05262 ; For quick lookup, the following table lists the PLAYERs and what space objects
05263 ; they represent in this subroutine:
05264 ;
05265 ; +--------+---------------------------------+
05266 ; | PLAYER | Represents |
05267 ; +--------+---------------------------------+
05268 ; | 0 | Zylon Ship 0 |
05269 ; | 1 | Zylon Ship 1 |
05270 ; | 2 | Zylon Photon Torpedo, Meteor |
05271 ; | 3 | Our starship's Photon Torpedo 0 |
05272 ; | 4 | Our starship's Photon Torpedo 1 |
05273 ; +--------+---------------------------------+
05274 ;
05275 ; This subroutine executes the following steps:
05276 ;
05277 ; (1) Update the x and y velocity vector components of both of our starship's
05278 ; photon torpedoes 0 and 1.
05279 ;
05280 ; The x and y velocity vector components of both of our starship's photon
05281 ; torpedoes 0 and 1 are only updated if they are tracking (homing in on) a
05282 ; target.
05283 ;
05284 ; To update the y-velocity vector components of both of our starship's
05285 ; photon torpedoes 0 and 1 the PLAYER row number difference between the
05286 ; PLAYER of tracked target space object and the current location of the
05287 ; PLAYER of our starship's photon torpedo 0 is passed to subroutine
05288 ; HOMINGVEL ($AECA). It returns the new y-velocity vector component value
05289 ; for both of our starship's photon torpedoes in <KM/H>. If the target is
05290 ; located below our starship's photon torpedo 0 a value of 0 <KM/H> is
05291 ; used.
05292 ;
05293 ; NOTE: The new y-velocity vector components depend only on the PLAYER row
05294 ; number of our starship's photon torpedo 0.
05295 ;
05296 ; To update the x-velocity vector components of both of our starship's
05297 ; photon torpedoes, the above calculation is repeated for the PLAYER column
05298 ; numbers of each of our starship's photon torpedoes 0 and 1.
05299 ;
05300 ; (2) Make the Zylon ships follow the rotation of our starship.
05301 ;
05302 ; If you rotate our starship away from Zylon ships they adjust their course
05303 ; such that they reappear in our starship's view.
05304 ;
05305 ; This is achieved by 4 Zylon timers, one for each of both Zylon ships'
05306 ; current x and y Zylon velocity indices. The Zylon timers are decremented
05307 ; every game loop iteration. If any of them reach a value of 0, the
05308 ; corresponding Zylon velocity index is incremented or decremented
05309 ; depending on the current joystick position.
05310 ;
05311 ; For example, if the Zylon timer for the x-velocity of Zylon ship 0
05312 ; reaches 0 and at the same time the joystick is pushed left then the
05313 ; x-Zylon velocity index of this Zylon ship is incremented. This
05314 ; accelerates the Zylon ship toward negative x-direction ("left"): The
05315 ; Zylon ship follows our starship's rotation. This works in Aft view, too,
05316 ; where the direction of change of the Zylon velocity index is reversed.
05317 ; After setting the new Zylon velocity index, it is used to pick a new
05318 ; Zylon timer value for this Zylon velocity index:
05319 ;
05320 ; +--------------------------------+----+----+----+----+----+----+----+----+
05321 ; | Velocity Index | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
05322 ; +--------------------------------+----+----+----+----+----+----+----+----+
05323 ; | Zylon Timer Value (Game Loops) | 0 | 2 | 4 | 6 | 8 | 10 | 12 | 14 |
05324 ; +--------------------------------+----+----+----+----+----+----+----+----+
05325 ; +--------------------------------+----+----+----+----+----+----+----+----+
05326 ; | Velocity Index | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 |
05327 ; +--------------------------------+----+----+----+----+----+----+----+----+
05328 ; | Zylon Timer Value (Game Loops) | 14 | 12 | 10 | 8 | 6 | 4 | 2 | 0 |
05329 ; +--------------------------------+----+----+----+----+----+----+----+----+
05330 ;
05331 ; (3) Update the x and y velocity vector components of the single Zylon photon
05332 ; torpedo.
05333 ;
05334 ; If a Zylon photon torpedo is moving toward our starship then update its x
05335 ; and y velocity vector components. They are picked from table
05336 ; ZYLONHOMVELTAB ($BF85) and depend on the mission level. The signs of the
05337 ; velocity vector components are always set such that the Zylon photon
05338 ; torpedo is guided toward our starship.
05339 ;
05340 ; (4) Create a meteor?
05341 ;
05342 ; If PLAYER2, the PLAYER to represent a meteor, is either initial or not
05343 ; alive, then attempt in 7 out of 8 game loop iterations to create a new
05344 ; meteor.
05345 ;
05346 ; With a probability of 2% (4:256) a new meteor is created: Its shape type
05347 ; is set to METEOR, its position vector components to random coordinates in
05348 ; subroutine INITPOSVEC ($B764), its lifetime to 60 game loop iterations,
05349 ; and its velocity vector components (velocities) to x-velocity: 0 <KM/H>,
05350 ; y-velocity: 0 <KM/H>, z-velocity: -8 <KM/H>. Then code execution returns.
05351 ;
05352 ; (5) Toggle Zylon ship control.
05353 ;
05354 ; Every other game loop iteration, the game takes control of and maneuvers
05355 ; the other Zylon ship.
05356 ;
05357 ; (6) Create new Zylon ship?
05358 ;
05359 ; If the game-controlled Zylon ship is not alive, check if both Zylon ships
05360 ; are not alive and this is an empty sector. If so, then attempt to create
05361 ; a meteor. Otherwise create a new Zylon ship with infinite lifetime.
05362 ; Randomly pick its shape type from table ZYLONSHAPTAB ($BF89) (ZYLON
05363 ; BASESTAR, ZYLON CRUISER, or ZYLON FIGHTER) and its flight pattern from
05364 ; table ZYLONFLPATTAB ($BF91) (attack flight pattern 0 is always picked in
05365 ; a NOVICE mission). Then set the milestone timer to 1 game loop iteration
05366 ; and the position vector of the Zylon ship to a position of at least
05367 ; +28928 (+$71**) <KM> in front of our starship. The y-coordinate depends
05368 ; on the value of VICINITYMASK ($C7). The x-coordinate is the sum of the
05369 ; y-coordinate plus at least 4864..5119 ($13**) <KM>. Randomly choose the
05370 ; signs of the x and y coordinates.
05371 ;
05372 ; (7) Set the current flight pattern to attack flight pattern?
05373 ;
05374 ; The current flight pattern of the Zylon ship will change to attack flight
05375 ; pattern if it is close enough (z-coordinate < +8192 (+$20**) <KM>) and
05376 ; one of the following conditions is met:
05377 ;
05378 ; o The Zylon ship is located behind our starship.
05379 ;
05380 ; o The shape of the Zylon ship is not initial and does not currently
05381 ; appear as a blip in the Long-Range Scan view.
05382 ;
05383 ; (8) Update the back-attack flag and the milestone velocity indices.
05384 ;
05385 ; The milestone timer is decremented for the game-controlled Zylon ship. If
05386 ; this timer reaches a value of 0 the following steps are executed:
05387 ;
05388 ; o The milestone timer is reset to a value of 120 game loop iterations.
05389 ;
05390 ; o The back-attack flag is updated. It determines if the game-controlled
05391 ; Zylon ship not only attacks from the front of our starship but also
05392 ; from the back. A back-attack takes place with a probability of 19%
05393 ; (48:256) in WARRIOR or COMMANDER missions.
05394 ;
05395 ; o Course corrections are prepared for the game-controlled Zylon ship by
05396 ; computing the new milestone vector indices, resulting in new velocity
05397 ; vector components for this Zylon ship. The new milestone velocity
05398 ; indices for each velocity vector component are randomly chosen
05399 ; depending of the flight pattern. Recall that the Zylon velocity index
05400 ; is changed gradually to match the milestone velocity index. It
05401 ; corresponds to a maximum velocity vector component when using this
05402 ; index to pick a velocity vector component from Zylon velocity table
05403 ; ZYLONVELTAB ($BF99):
05404 ;
05405 ; +----------------+----------------+------------------+
05406 ; | Flight Pattern | New Milestone | Maximum Velocity |
05407 ; | | Velocity Index | Vector Component |
05408 ; +----------------+----------------+------------------+
05409 ; | 0 | 0 | +62 <KM/H> |
05410 ; | 0 | 15 | -62 <KM/H> |
05411 ; | 1 | 1 | +30 <KM/H> |
05412 ; | 1 | 14 | -30 <KM/H> |
05413 ; | 4 | 4 | +4 <KM/H> |
05414 ; | 4 | 11 | -4 <KM/H> |
05415 ; +----------------+----------------+------------------+
05416 ;
05417 ; (9) Update milestone velocity indices in attack flight pattern.
05418 ;
05419 ; If a Zylon ship executes the attack flight pattern, its milestone
05420 ; velocity indices are changed depending on the current location of the
05421 ; Zylon ship as follows:
05422 ;
05423 ; +--------------+-------------+----------------+------------+----------------+
05424 ; | x-Coordinate | Where on | Milestone | Velocity | Zylon Ship |
05425 ; | | Screen | Velocity Index | | Accelerates... |
05426 ; +--------------+-------------+----------------+------------+----------------+
05427 ; | x < 0 <KM> | left half | 0 | +62 <KM/H> | to the right |
05428 ; | x >= 0 <KM> | right half | 15 | -62 <KM/H> | to the left |
05429 ; +--------------+-------------+----------------+------------+----------------+
05430 ; +--------------+-------------+----------------+------------+----------------+
05431 ; | y-Coordinate | Where on | Milestone | Velocity | Zylon Ship |
05432 ; | | Screen | Velocity Index | | Accelerates... |
05433 ; +--------------+-------------+----------------+------------+----------------+
05434 ; | y < 0 <KM> | bottom half | 0 | +62 <KM/H> | up |
05435 ; | y >= 0 <KM> | top half | 15 | -62 <KM/H> | down |
05436 ; +--------------+-------------+----------------+------------+----------------+
05437 ;
05438 ; Thus, with respect to its x and y coordinates, the Zylon ship oscillates
05439 ; around the center of the Front or Aft view.
05440 ;
05441 ; This is the behavior of the Zylon ship along the z-axis:
05442 ;
05443 ; If the Zylon ship attacks from the front:
05444 ;
05445 ; +--------------------------+----------------+------------+----------------+
05446 ; | z-Coordinate | Milestone | Velocity | Zylon Ship |
05447 ; | | Velocity Index | | Accelerates... |
05448 ; +--------------------------+----------------+------------+----------------+
05449 ; | z < +2560 (+$0A00) <KM> | 0 | +62 <KM/H> | outbound |
05450 ; | z >= +2560 (+$0A00) <KM> | 15 | -62 <KM/H> | inbound |
05451 ; +--------------------------+----------------+------------+----------------+
05452 ;
05453 ; In other words, the Zylon ship accelerates into positive z-direction
05454 ; (outbound) up to a distance of +2560 (+$0A00) <KM>, then reverses its
05455 ; course and returns back to our starship (inbound).
05456 ;
05457 ; If the Zylon ship attacks from the back:
05458 ;
05459 ; +--------------------------+----------------+------------+----------------+
05460 ; | z-Coordinate | Milestone | Velocity | Zylon Ship |
05461 ; | | Velocity Index | | Accelerates... |
05462 ; +--------------------------+----------------+------------+----------------+
05463 ; | z < -2816 (-$F500) <KM> | 0 | +62 <KM/H> | inbound |
05464 ; | z >= -2816 (-$F500) <KM> | 15 | -62 <KM/H> | outbound |
05465 ; +--------------------------+----------------+------------+----------------+
05466 ;
05467 ; In other words, the Zylon ship accelerates into negative z-direction
05468 ; (outbound) up to a distance of -2816 (-$(0B00)) <KM>, then reverses its
05469 ; course and returns back to our starship (inbound).
05470 ;
05471 ; (10) Change Zylon velocity index toward milestone velocity index.
05472 ;
05473 ; Compare all 3 Zylon velocity indices of the game-controlled Zylon ship
05474 ; with their corresponding milestone velocity indices. Increment or
05475 ; decrement the former to better match the latter. Use the new Zylon
05476 ; velocity indices to pick the current velocity values from Zylon velocity
05477 ; table ZYLONVELTAB ($BF99).
05478 ;
05479 ; (11) Launch a Zylon photon torpedo?
05480 ;
05481 ; Prepare launching a Zylon photon torpedo if either of the following
05482 ; conditions are met:
05483 ;
05484 ; o PLAYER2 is not used as a photon torpedo
05485 ;
05486 ; o The y-coordinate of the Zylon ship is in the range of -768..+767
05487 ; (-$0300..+$2FF) <KM>.
05488 ;
05489 ; or if
05490 ;
05491 ; o The Zylon photon torpedo is not alive
05492 ;
05493 ; o The corresponding Zylon photon torpedo delay timer has reached a
05494 ; value of 0
05495 ;
05496 ; o The y-coordinate of the Zylon ship is in the range of -768..+767
05497 ; (-$0300..+$2FF) <KM>.
05498 ;
05499 ; At this point the z-velocity vector component of the Zylon photon torpedo
05500 ; is preloaded with a value of -80 or +80 <KM/H> depending on the Zylon
05501 ; ship being in front or behind of our starship, respectively.
05502 ;
05503 ; Launch a Zylon photon torpedo if both of the following conditions are
05504 ; met:
05505 ;
05506 ; o The Zylon ship is in front or behind of our starship, with the
05507 ; exception of a Zylon ship behind our starship in a NOVICE mission
05508 ; (our starship will never be shot in the back in a NOVICE mission).
05509 ;
05510 ; o The z-coordinate of the Zylon ship (no matter if in front or behind
05511 ; our starship) is closer than 8192 ($20**) <KM>.
05512 ;
05513 ; Finally, the Zylon photon torpedo is launched with a lifetime of 62 game
05514 ; loop iterations. Its position vector is copied from the launching Zylon
05515 ; ship in subroutine COPYPOSVEC ($ACAF). In addition, the Zylon ship is
05516 ; earmarked for the tracking computer.
05517
=006A 05518 L.CTRLDZYLON = $6A ; Index of currently game-controlled Zylon ship.
05519 ; Used values are:
05520 ; 0 -> Control Zylon ship 0
05521 ; 1 -> Control Zylon ship 1
=0080 05522 NEG = $80 ; Negative sign bit for velocity vector component
05523
AA79 A5C0 05524 MANEUVER LDA WARPSTATE ; Return if in starbase sector or hyperwarp engaged
AA7B 057B 05525 ORA ISSTARBASESECT ;
AA7D D0F9 05526 BNE SKIP078 ;
05527
05528 ;*** Update x and y velocity of both our starship's photon torpedoes 0 and 1 ***
AA7F A586 05529 LDA ISTRACKING ; Skip this if ship's torpedoes not tracking a target
AA81 F030 05530 BEQ SKIP080 ;
05531
AA83 A689 05532 LDX PLTRACKED ; Load PLAYER index of tracked target space object
05533
AA85 38 05534 SEC ; Prep A := PLAYER row number of target...
AA86 BDF90B 05535 LDA PL0ROWNEW,X ; ...- PLAYER row number photon torpedo 0
AA89 EDFC0B 05536 SBC PL3ROWNEW ;
AA8C 9002 05537 BCC SKIP079 ; Skip if target above our starship's photon torpedo
AA8E A900 05538 LDA #0 ; Prep A := 0
AA90 20CAAE 05539 SKIP079 JSR HOMINGVEL ; Get y-velocity for homing photon torpedo 0 and 1
AA93 8DCB0B 05540 STA PL3YVEL ; Store y-velocity photon torpedo 0
AA96 8DCC0B 05541 STA PL4YVEL ; Store y-velocity photon torpedo 1
05542
AA99 38 05543 SEC ; Prep A := PLAYER column number of target...
AA9A AD2D0C 05544 LDA PL3COLUMN ; ...- PLAYER column number of photon torpedo 0
AA9D FD2A0C 05545 SBC PL0COLUMN,X ;
AAA0 20CAAE 05546 JSR HOMINGVEL ; Get x-velocity for homing photon torpedo 0
AAA3 8D9A0B 05547 STA PL3XVEL ; Store x-velocity of photon torpedo 0
05548
AAA6 38 05549 SEC ; Prep A := PLAYER column number of target...
AAA7 AD2E0C 05550 LDA PL4COLUMN ; ...- PLAYER column number of photon torpedo 1
AAAA FD2A0C 05551 SBC PL0COLUMN,X ;
AAAD 20CAAE 05552 JSR HOMINGVEL ; Get x-velocity for homing photon torpedo 1
AAB0 8D9B0B 05553 STA PL4XVEL ; Store x-velocity of photon torpedo 1
05554
05555 ;*** Make Zylon ships follow rotation of our starship **************************
AAB3 A203 05556 SKIP080 LDX #3 ; Loop over x and y velocity indices of both Zylons
AAB5 D6BA 05557 LOOP036 DEC ZYLONTIMX0,X ; Decrement Zylon timer
AAB7 1027 05558 BPL SKIP085 ; Next timer if this one still counting down
05559
AAB9 8A 05560 TXA ; Prep joystick (x or y) value in -1, 0, +1
AABA 4A 05561 LSR A ;
AABB A8 05562 TAY ;
AABC B9C800 05563 LDA JOYSTICKX,Y ;
05564
AABF A4D0 05565 LDY SHIPVIEW ; Skip if in Front view
AAC1 F005 05566 BEQ SKIP081 ;
05567
AAC3 49FF 05568 EOR #$FF ; Invert joystick value (when in Aft view)
AAC5 18 05569 CLC ; (two's-complement)
AAC6 6901 05570 ADC #1 ;
05571
AAC8 18 05572 SKIP081 CLC ; Add joystick value to Zylon velocity index
AAC9 75B4 05573 ADC ZYLONVELINDX0,X ;
AACB 1002 05574 BPL SKIP082 ;
AACD A900 05575 LDA #0 ;
AACF C910 05576 SKIP082 CMP #16 ; Limit new Zylon velocity index to 0..15 ...
AAD1 9002 05577 BCC SKIP083 ;
AAD3 A90F 05578 LDA #15 ;
AAD5 95B4 05579 SKIP083 STA ZYLONVELINDX0,X ; ...and store new Zylon velocity index
05580
AAD7 C908 05581 CMP #8 ; Calc new Zylon timer value in 0, 2, ..., 14
AAD9 9002 05582 BCC SKIP084 ;
AADB 490F 05583 EOR #$0F ;
AADD 0A 05584 SKIP084 ASL A ;
AADE 95BA 05585 STA ZYLONTIMX0,X ; ...and store new Zylon timer value
05586
AAE0 CA 05587 SKIP085 DEX ;
AAE1 10D2 05588 BPL LOOP036 ; Next Zylon timer
05589
05590 ;*** Update x and y velocity of single Zylon photon torpedo ********************
AAE3 AD8E0C 05591 LDA PL2SHAPTYPE ; Skip if PLAYER2 not PHOTON TORPEDO (shape type 0)
AAE6 D01B 05592 BNE SKIP088 ;
05593
AAE8 A462 05594 LDY MISSIONLEVEL ; Depending on mission level...
AAEA B985BF 05595 LDA ZYLONHOMVELTAB,Y ; ...pick (initially negative) Zylon torpedo velocity
05596
AAED AEA40A 05597 LDX PL2YPOSHI ; If photon torpedo in upper screen half (y >= 0)...
AAF0 1002 05598 BPL SKIP086 ; ...don't toggle velocity sign -> torpedo goes down
AAF2 297F 05599 AND #$7F ; ...toggle velocity sign -> torpedo goes up
AAF4 8DCA0B 05600 SKIP086 STA PL2YVEL ; Store new y-velocity of Zylon photon torpedo
05601
AAF7 0980 05602 ORA #NEG ; Restore negative sign bit of velocity
05603
AAF9 AE730A 05604 LDX PL2XPOSHI ; If photon torpedo in right screen half (x >= 0)...
AAFC 1002 05605 BPL SKIP087 ; ...don't toggle velocity sign -> torpedo goes left
AAFE 297F 05606 AND #$7F ; ...toggle velocity sign -> torpedo goes right
AB00 8D990B 05607 SKIP087 STA PL2XVEL ; Store new x-velocity of Zylon photon torpedo
05608
05609 ;*** Create new meteor? ********************************************************
AB03 A576 05610 SKIP088 LDA COUNT256 ; Attempt meteor creation in 7 out of 8 game loops
AB05 2903 05611 AND #$03 ;
AB07 F02E 05612 BEQ SKIP092 ;
05613
AB09 A5E6 05614 SKIP089 LDA PL2SHAPOFF ; If PLAYER2 shape is initial try to create a meteor
AB0B F004 05615 BEQ SKIP090 ;
05616
AB0D A5EB 05617 LDA PL2LIFE ; Return if PLAYER2 alive
AB0F D025 05618 BNE SKIP091 ;
05619
AB11 AD0AD2 05620 SKIP090 LDA RANDOM ; Return in 98% (252:256) (do not create meteor)
AB14 C904 05621 CMP #4 ;
AB16 B01E 05622 BCS SKIP091 ;
05623
05624 ;*** Create new meteor! ********************************************************
AB18 A960 05625 LDA #SHAP.METEOR ; PLAYER2 is METEOR (shape type 6)
AB1A 8D8E0C 05626 STA PL2SHAPTYPE ;
AB1D A202 05627 LDX #2 ; Randomize position vector of meteor
AB1F 2064B7 05628 JSR INITPOSVEC ;
AB22 A93C 05629 LDA #60 ; Meteor lifetime := 60 game loops
AB24 85EB 05630 STA PL2LIFE ;
AB26 A988 05631 LDA #NEG!8 ; SUMMARY:
AB28 8D680B 05632 STA PL2ZVEL ; x-velocity := 0 <KM/H>
AB2B A900 05633 LDA #0 ; y-velocity := 0 <KM/H>
AB2D 8D2C0C 05634 STA PL2COLUMN ; z-velocity := -8 <KM/H>
AB30 8D990B 05635 STA PL2XVEL ;
AB33 8DCA0B 05636 STA PL2YVEL ; PLAYER2 column number := 0 (offscreen)
AB36 60 05637 SKIP091 RTS ; Return
05638
05639 ;*** Toggle Zylon ship control *************************************************
AB37 A5A7 05640 SKIP092 LDA CTRLDZYLON ; Toggle control to the other Zylon ship
AB39 4901 05641 EOR #$01 ;
AB3B 85A7 05642 STA CTRLDZYLON ;
05643
05644 ;*** Create a new Zylon ship? **************************************************
AB3D AA 05645 TAX ; Save index of controlled Zylon ship
AB3E B5E9 05646 LDA PL0LIFE,X ; Skip creating Zylon ship if its PLAYER still alive
AB40 D042 05647 BNE SKIP094 ;
05648
AB42 A5E9 05649 LDA PL0LIFE ; If both Zylon ships are not alive...
AB44 05EA 05650 ORA PL1LIFE ;
AB46 2901 05651 AND #$01 ;
AB48 A490 05652 LDY CURRSECTOR ; ...and this an empty sector...
AB4A D9C908 05653 CMP GCMEMMAP,Y ;
AB4D B0BA 05654 BCS SKIP089 ; ...attempt to create meteor and return
05655
05656 ;*** Create a new Zylon ship! **************************************************
AB4F A9FF 05657 LDA #255 ; Zylon ship lifetime := 255 game loops (infinite)
AB51 95E9 05658 STA PL0LIFE,X ;
05659
AB53 AD0AD2 05660 LDA RANDOM ; Pick a Zylon ship shape type (1 out of 8)
AB56 2907 05661 AND #$07 ;
AB58 A8 05662 TAY ;
AB59 B989BF 05663 LDA ZYLONSHAPTAB,Y ;
AB5C 9D8C0C 05664 STA PL0SHAPTYPE,X ;
05665
AB5F A562 05666 LDA MISSIONLEVEL ; Init Zylon's flight pattern (0 if NOVICE mission)
AB61 F003 05667 BEQ SKIP093 ;
AB63 B991BF 05668 LDA ZYLONFLPATTAB,Y ;
AB66 95A8 05669 SKIP093 STA ZYLONFLPAT0,X ;
05670
AB68 A901 05671 LDA #1 ; Zylon ship's milestone timer := 1 game loop
AB6A 95AA 05672 STA MILESTTIM0,X ;
05673
AB6C 9DAD09 05674 STA ZPOSSIGN,X ; Put Zylon ship in front of our starship
AB6F AD0AD2 05675 LDA RANDOM ;
AB72 25C7 05676 AND VICINITYMASK ; y-coordinate (high byte) := RND(0..VICINITYMASK)
AB74 9DA20A 05677 STA YPOSHI,X ;
AB77 6913 05678 ADC #19 ; x-coordinate (high byte) := y (high byte) + 19
AB79 9D710A 05679 STA XPOSHI,X ;
AB7C 0971 05680 ORA #$71 ; z-coordinate (high byte) := >= +28928 (+$71**) <KM>
AB7E 9D400A 05681 STA ZPOSHI,X ;
AB81 20BEB7 05682 JSR RNDINVXY ; Randomly invert x and y coordinate of pos vector
05683
05684 ;*** Set current flight pattern to attack flight pattern? **********************
AB84 BD400A 05685 SKIP094 LDA ZPOSHI,X ; Skip if Zylon too distant (z >= +$20** <KM>)
AB87 C920 05686 CMP #$20 ;
AB89 B011 05687 BCS SKIP096 ;
05688
AB8B BDAD09 05689 LDA ZPOSSIGN,X ; Set attack flight pattern if Zylon is behind
AB8E F008 05690 BEQ SKIP095 ;
05691
AB90 B5E4 05692 LDA PL0SHAPOFF,X ; Skip if Zylon shape initial
AB92 F008 05693 BEQ SKIP096 ;
05694
AB94 C929 05695 CMP #$29 ; Skip if Zylon shape is Long-Range Scan blip
AB96 F004 05696 BEQ SKIP096 ;
05697
AB98 A900 05698 SKIP095 LDA #0 ; Set attack flight pattern
AB9A 95A8 05699 STA ZYLONFLPAT0,X ;
05700
05701 ;*** Update back-attack flag and milestone velocity indices ********************
AB9C D6AA 05702 SKIP096 DEC MILESTTIM0,X ; Skip if milestone timer still counting down
AB9E 1024 05703 BPL SKIP099 ;
05704
ABA0 A978 05705 LDA #120 ; Milestone timer := 120 game loops
ABA2 95AA 05706 STA MILESTTIM0,X ;
05707
ABA4 A562 05708 LDA MISSIONLEVEL ; Back-attack flag := 1 in 19% (48:256) of...
ABA6 AC0AD2 05709 LDY RANDOM ; ...WARRIOR or COMMANDER missions
ABA9 C030 05710 CPY #48 ; ... := 0 otherwise
ABAB 9001 05711 BCC SKIP097 ;
ABAD 4A 05712 LSR A ;
ABAE 4A 05713 SKIP097 LSR A ;
ABAF 95B8 05714 STA ISBACKATTACK0,X ;
05715
05716 ; Loop over all 3 milestone velocity indices
ABB1 B5A8 05717 LDA ZYLONFLPAT0,X ; Set new milestone velocity index:
ABB3 2C0AD2 05718 LOOP037 BIT RANDOM ; If Zylon flight pattern is...
ABB6 1002 05719 BPL SKIP098 ; ...0 -> milestone velocity index := either 0 or 15
ABB8 490F 05720 EOR #$0F ; ...1 -> milestone velocity index := either 1 or 14
ABBA 95AC 05721 SKIP098 STA MILESTVELINDZ0,X ; ...4 -> milestone velocity index := either 4 or 11
ABBC E8 05722 INX ;
ABBD E8 05723 INX ;
ABBE E006 05724 CPX #6 ;
ABC0 90F1 05725 BCC LOOP037 ; Next Zylon milestone velocity index
05726
05727 ;*** Update milestone velocity indices in attack flight pattern ****************
ABC2 A6A7 05728 LDX CTRLDZYLON ; Reload index of controlled Zylon ship
05729
ABC4 B5A8 05730 SKIP099 LDA ZYLONFLPAT0,X ; Skip if not in attack flight pattern
ABC6 D032 05731 BNE SKIP105 ;
05732
ABC8 A4A7 05733 LDY CTRLDZYLON ; Reload index of controlled Zylon ship
05734
05735 ; Loop over all 3 milestone velocity indices
ABCA C031 05736 LOOP038 CPY #$31 ; Skip to handle x and y velocity index
ABCC B013 05737 BCS SKIP101 ;
05738 ; SUMMARY:
ABCE B9B800 05739 LDA ISBACKATTACK0,Y ; Handle z-velocity index:
ABD1 4A 05740 LSR A ;
ABD2 B9400A 05741 LDA ZPOSHI,Y ; If Zylon attacks from front...
ABD5 B006 05742 BCS SKIP100 ; z < $0A00 <KM> -> mil vel index := 0 (+62 <KM/H>)
ABD7 C90A 05743 CMP #$0A ; z >= $0A00 <KM> -> mil vel index := 15 (-62 <KM/H>)
ABD9 900E 05744 BCC SKIP103 ;
ABDB B004 05745 BCS SKIP101 ; If Zylon attacks from back...
ABDD C9F5 05746 SKIP100 CMP #$F5 ; z >= $F500 <KM> -> mil vel index := 15 (-62 <KM/H>)
ABDF B004 05747 BCS SKIP102 ; z < $F500 <KM> -> mil vel index := 0 (+62 <KM/H>)
05748
ABE1 B9AD09 05749 SKIP101 LDA ZPOSSIGN,Y ; Handle x and y velocity index:
ABE4 4A 05750 LSR A ;
ABE5 A90F 05751 SKIP102 LDA #15 ; x >= 0 <KM> -> mil vel index := 15 (-62 <KM/H>)
ABE7 B002 05752 BCS SKIP104 ; x < 0 <KM> -> mil vel index := 0 (+62 <KM/H>)
ABE9 A900 05753 SKIP103 LDA #0 ; y >= 0 <KM> -> mil vel index := 15 (-62 <KM/H>)
ABEB 95AC 05754 SKIP104 STA MILESTVELINDZ0,X ; y < 0 <KM> -> mil vel index := 0 (+62 <KM/H>)
05755
ABED 18 05756 CLC ; Adjust position vector component index
ABEE 98 05757 TYA ;
ABEF 6931 05758 ADC #NUMSPCOBJ.ALL ;
ABF1 A8 05759 TAY ;
05760
ABF2 E8 05761 INX ;
ABF3 E8 05762 INX ;
ABF4 E006 05763 CPX #6 ;
ABF6 90D2 05764 BCC LOOP038 ; Next milestone velocity index
05765
05766 ;*** Acceleration: Change Zylon velocity index toward milestone velocity index *
ABF8 A6A7 05767 LDX CTRLDZYLON ; Reload index of controlled Zylon ship
ABFA A4A7 05768 SKIP105 LDY CTRLDZYLON ; Reload index of controlled Zylon ship
05769
05770 ; Loop over all 3 milestone velocity indices
ABFC B5B2 05771 LOOP039 LDA ZYLONVELINDZ0,X ; Compare Zylon velocity index with milestone index
ABFE D5AC 05772 CMP MILESTVELINDZ0,X ;
AC00 F008 05773 BEQ SKIP107 ; Skip if equal
AC02 B004 05774 BCS SKIP106 ;
AC04 F6B2 05775 INC ZYLONVELINDZ0,X ; Increm. Zylon velocity index if < milestone index
AC06 9002 05776 BCC SKIP107 ;
AC08 D6B2 05777 SKIP106 DEC ZYLONVELINDZ0,X ; Decrem. Zylon velocity index if >= milestone index
05778
AC0A 866A 05779 SKIP107 STX L.CTRLDZYLON ; Save index of controlled Zylon ship
AC0C AA 05780 TAX ;
AC0D BD99BF 05781 LDA ZYLONVELTAB,X ; Pick new velocity value by Zylon velocity index
AC10 A66A 05782 LDX L.CTRLDZYLON ; Reload index of controlled Zylon ship
AC12 99660B 05783 STA ZVEL,Y ; Store new velocity vector component of Zylon ship
05784
AC15 98 05785 TYA ; Next velocity vector component
AC16 18 05786 CLC ;
AC17 6931 05787 ADC #NUMSPCOBJ.ALL ;
AC19 A8 05788 TAY ;
05789
AC1A E8 05790 INX ;
AC1B E8 05791 INX ;
AC1C E006 05792 CPX #6 ;
AC1E 90DC 05793 BCC LOOP039 ; Next milestone velocity index
05794
05795 ;*** Launch Zylon photon torpedo? **********************************************
05796
05797 ;*** Check PLAYER2 shape and lifetime ******************************************
AC20 A6A7 05798 LDX CTRLDZYLON ; Reload index of controlled Zylon ship
05799
AC22 AD8E0C 05800 LDA PL2SHAPTYPE ; Skip if PLAYER2 not PHOTON TORPEDO (shape type 0)
AC25 D00B 05801 BNE SKIP109 ;
05802
AC27 A5EB 05803 LDA PL2LIFE ; Return if Zylon photon torpedo still alive
AC29 D006 05804 BNE SKIP108 ;
05805
AC2B A5BE 05806 LDA TORPEDODELAY ; Count down Zylon photon torpedo delay timer...
AC2D F003 05807 BEQ SKIP109 ; ...before launching next Zylon photon torpedo
AC2F C6BE 05808 DEC TORPEDODELAY ;
AC31 60 05809 SKIP108 RTS ; Return
05810
05811 ;*** Check y-coordinate of Zylon ship ******************************************
AC32 18 05812 SKIP109 CLC ; Return if Zylon ship's y-coordinate not...
AC33 BDA20A 05813 LDA YPOSHI,X ; ...in -768..+767 (-$(0300)..+$2FF) <KM>.
AC36 6902 05814 ADC #2 ;
AC38 C905 05815 CMP #5 ;
AC3A B0F5 05816 BCS SKIP108 ;
05817
05818 ;*** Set Zylon photon torpedo's z-velocity *************************************
AC3C A0D0 05819 LDY #NEG!80 ; Prep Zylon torpedo's z-velocity := -80 <KM/H>
05820
AC3E BDAD09 05821 LDA ZPOSSIGN,X ; Prep Zylon ship's sign of z-coordinate
AC41 4A 05822 LSR A ;
AC42 BD400A 05823 LDA ZPOSHI,X ; Prep Zylon ship's z-coordinate
AC45 B008 05824 BCS SKIP110 ; Skip if Zylon ship in front...
AC47 49FF 05825 EOR #$FF ; ...else invert loaded Zylon ship's z-coordinate
05826
AC49 A462 05827 LDY MISSIONLEVEL ; Return (no torpedo from back) if NOVICE mission
AC4B F0E4 05828 BEQ SKIP108 ;
05829
AC4D A050 05830 LDY #80 ; Preload Zylon torpedo's z-velocity := +80 <KM/H>
05831
05832 ;*** Is Zylon ship in range? ***************************************************
AC4F C920 05833 SKIP110 CMP #$20 ; Return if Zylon ship too far...
AC51 B0DE 05834 BCS SKIP108 ; ... (ABS(z-coordinate) > 8192 ($20**) <KM>)
05835
AC53 8C680B 05836 STY PL2ZVEL ; Store Zylon photon torpedo's z-velocity
05837
05838 ;*** Launch Zylon photon torpedo! **********************************************
05839
AC56 A900 05840 LDA #0 ; PLAYER2 is PHOTON TORPEDO (shape type 0)
AC58 8D8E0C 05841 STA PL2SHAPTYPE ;
AC5B 8D2C0C 05842 STA PL2COLUMN ; Zylon torpedo PLAYER column number := 0 (offscreen)
AC5E A93E 05843 LDA #62 ;
AC60 85EB 05844 STA PL2LIFE ; Zylon torpedo lifetime := 62 game loops
05845
AC62 A202 05846 LDX #2 ; Prep source index for position vector copy
AC64 A4A7 05847 LDY CTRLDZYLON ; Prep destination index for position vector copy
AC66 84BF 05848 STY ZYLONATTACKER ; Save Zylon ship index for tracking computer
AC68 4CAFAC 05849 JMP COPYPOSVEC ; Copy position vector from Zylon ship to its torpedo
05850
05851 ;*******************************************************************************
05852 ;* *
05853 ;* INITEXPL *
05854 ;* *
05855 ;* Initialize explosion *
05856 ;* *
05857 ;*******************************************************************************
05858
05859 ; DESCRIPTION
05860 ;
05861 ; Initializes the explosion's lifetime, the explosion fragments' position and
05862 ; velocity vectors as well as their pixel row and column numbers.
05863 ;
05864 ; An explosion has a lifetime of 128 game loop iterations. It consists of 32
05865 ; explosion fragment space objects with indices 17..48. The position vector of
05866 ; each explosion fragment is copied from the exploding PLAYER space object.
05867 ;
05868 ; The pixel column number of each explosion fragment is initialized to
05869 ;
05870 ; PIXEL COLUMN NUMBER := PLAYER column number - 48 + RND(0..15)
05871 ;
05872 ; To convert PLAYER column numbers (in Player/Missile (PM) pixels) into pixel
05873 ; column numbers, the PLAYER column number of the left PLAYFIELD border (= 48)
05874 ; is subtracted and a random number is added.
05875 ;
05876 ; BUG (at $AC76): The added random number should not be in 0..15 but in 0..7
05877 ; because the exploding PLAYER is 8 pixels wide. The PLAYER column number
05878 ; represents the left edge of the PLAYER shape. When using a random number in
05879 ; 0..15, half of the pixels are located off to the right of the PLAYER, outside
05880 ; the PLAYER area. Suggested fix: Replace instruction AND #$0F with AND #$07.
05881 ;
05882 ; The pixel row number of each explosion fragment is initialized to
05883 ;
05884 ; PIXEL ROW NUMBER := (PLAYER row number - RND(0..15)) / 2 - 16
05885 ;
05886 ; BUG (at $AC88): To convert PLAYER row numbers (in PM pixels) into pixel row
05887 ; numbers, the PLAYER row number to the top PLAYFIELD border (= 16) should be
05888 ; subtracted first, then the division by 2 (instruction LRS A) should be applied
05889 ; to reduce the double-line PM resolution to the single-line PLAYFIELD
05890 ; resolution. Suggested fix: Swap instruction LRS A with SBC #16 which leads to
05891 ; the following formula for the pixel row number:
05892 ;
05893 ; PIXEL ROW NUMBER := (PLAYER row number - 16 + RND(0..15)) / 2
05894 ;
05895 ; Incidentally, adding a random number in 0..15 is correct. PLAYER row number
05896 ; represents the top edge of the PLAYER shape, which is typically 16 PM pixels
05897 ; tall when representing a close space object.
05898 ;
05899 ; The velocity vector of explosion fragments is set to random x, y, and z
05900 ; velocity vector components in -7..+7 <KM/H>.
05901 ;
05902 ; INPUT
05903 ;
05904 ; Y = PLAYER index from which the explosion originates. Used values are:
05905 ; 0 -> Explosion of PLAYER0 (Zylon ship 0)
05906 ; 1 -> Explosion of PLAYER1 (Zylon ship 1)
05907 ; 2 -> Explosion of PLAYER2 (Zylon photon torpedo, starbase, or meteor)
05908
AC6B A980 05909 INITEXPL LDA #128 ; Explosion lifetime := 128 game loops
AC6D 8573 05910 STA EXPLLIFE ;
05911
AC6F A230 05912 LDX #NUMSPCOBJ.ALL-1 ; Max index of space objects (for explosion frags)
AC71 8679 05913 STX MAXSPCOBJIND ;
05914
05915 ; Loop over all explosion fragment position vectors
05916 ; (index 48..17)
AC73 AD0AD2 05917 LOOP040 LDA RANDOM ; PIXEL COLUMN NUM := PLAYER column - 48 + RND(0..15)
AC76 290F 05918 AND #$0F ; (!)
AC78 792A0C 05919 ADC PL0COLUMN,Y ;
AC7B E930 05920 SBC #48 ;
AC7D 9D2A0C 05921 STA PIXELCOLUMN,X ;
05922
AC80 AD0AD2 05923 LDA RANDOM ; PIXEL ROW NUM := (PLAYER row + RND(0..15)) / 2 - 16
AC83 290F 05924 AND #$0F ;
AC85 79F90B 05925 ADC PL0ROWNEW,Y ;
AC88 4A 05926 LSR A ; (!)
AC89 E910 05927 SBC #16 ;
AC8B 9DF90B 05928 STA PIXELROWNEW,X ;
05929
AC8E 20AFAC 05930 JSR COPYPOSVEC ; Copy position vector of PLAYER to explosion frag
05931
AC91 AD0AD2 05932 LDA RANDOM ; z-velocity := RND(-7..+7) <KM/H>
AC94 2987 05933 AND #NEG!7 ;
AC96 9D660B 05934 STA ZVEL,X ;
AC99 AD0AD2 05935 LDA RANDOM ; x-velocity := RND(-7..+7) <KM/H>
AC9C 2987 05936 AND #NEG!7 ;
AC9E 9D970B 05937 STA XVEL,X ;
ACA1 AD0AD2 05938 LDA RANDOM ; y-velocity := RND(-7..+7) <KM/H>
ACA4 2987 05939 AND #NEG!7 ;
ACA6 9DC80B 05940 STA YVEL,X ;
05941
ACA9 CA 05942 DEX ; Next explosion fragment position vector
ACAA E010 05943 CPX #16 ;
ACAC D0C5 05944 BNE LOOP040 ;
ACAE 60 05945 RTS ; Return
05946
05947 ;*******************************************************************************
05948 ;* *
05949 ;* COPYPOSVEC *
05950 ;* *
05951 ;* Copy a position vector *
05952 ;* *
05953 ;*******************************************************************************
05954
05955 ; DESCRIPTION
05956 ;
05957 ; Copies a position vector.
05958 ;
05959 ; Actually, this subroutine copies the z-coordinate only, then code execution
05960 ; continues into subroutine COPYPOSXY ($ACC1) to copy the x and y coordinate.
05961 ;
05962 ; INPUT
05963 ;
05964 ; X = Destination position vector index. Used values are: 0..48.
05965 ; Y = Source position vector index. Used values are: 0..48.
05966
ACAF B9AD09 05967 COPYPOSVEC LDA ZPOSSIGN,Y ;
ACB2 9DAD09 05968 STA ZPOSSIGN,X ;
ACB5 B9400A 05969 LDA ZPOSHI,Y ;
ACB8 9D400A 05970 STA ZPOSHI,X ;
ACBB B9D30A 05971 LDA ZPOSLO,Y ;
ACBE 9DD30A 05972 STA ZPOSLO,X ;
05973
05974 ;*******************************************************************************
05975 ;* *
05976 ;* COPYPOSXY *
05977 ;* *
05978 ;* Copy x and y components (coordinates) of position vector *
05979 ;* *
05980 ;*******************************************************************************
05981
05982 ; DESCRIPTION
05983 ;
05984 ; Copies the x and y components (coordinates) of a position vector.
05985 ;
05986 ; INPUT
05987 ;
05988 ; X = Destination position vector index. Used values are: 0..48.
05989 ; Y = Source position vector index. Used values are: 0..48.
05990
ACC1 B9DE09 05991 COPYPOSXY LDA XPOSSIGN,Y ;
ACC4 9DDE09 05992 STA XPOSSIGN,X ;
ACC7 B9710A 05993 LDA XPOSHI,Y ;
ACCA 9D710A 05994 STA XPOSHI,X ;
ACCD B90F0A 05995 LDA YPOSSIGN,Y ;
ACD0 9D0F0A 05996 STA YPOSSIGN,X ;
ACD3 B9A20A 05997 LDA YPOSHI,Y ;
ACD6 9DA20A 05998 STA YPOSHI,X ;
ACD9 B9040B 05999 LDA XPOSLO,Y ;
ACDC 9D040B 06000 STA XPOSLO,X ;
ACDF B9350B 06001 LDA YPOSLO,Y ;
ACE2 9D350B 06002 STA YPOSLO,X ;
ACE5 60 06003 SKIP111 RTS ; Return
06004
06005 ;*******************************************************************************
06006 ;* *
06007 ;* DOCKING *
06008 ;* *
06009 ;* Handle docking at starbase, launch and return of transfer vessel *
06010 ;* *
06011 ;*******************************************************************************
06012
06013 ; DESCRIPTION
06014 ;
06015 ; Handles docking at a starbase, launching and returning the transfer vessel,
06016 ; and repairing our starship's subsystems.
06017 ;
06018 ; This subroutine changes, if in Front view, the PLAYER-PLAYFIELD priority such
06019 ; that PLAYERs like the starbase appear behind the cross hairs, which are part
06020 ; of the PLAYFIELD.
06021 ;
06022 ; BUG (at $ACEE): In Front view, the specific order of PLAYERs (PL0..4) and
06023 ; PLAYFIELD colors (PF0..4) is, from front to back:
06024 ;
06025 ; PL4 > PF0, PF1, PF2 > PL0 > PL1 > PL2 > PL3 > PF4 (BGR)
06026 ;
06027 ; This makes the starbase appear behind the cross hairs, but also behind the
06028 ; stars, as both cross hairs and stars are part of the PLAYFIELD - a rarely
06029 ; noticed glitch.
06030 ;
06031 ; Note also that, as an exception of the rule, PLAYER4 (transfer vessel) is
06032 ; displayed before the PLAYFIELD. Thus, the transfer vessel appears in front of
06033 ; the cross hairs!
06034 ;
06035 ; In Aft view, the arrangement is reversed: PLAYERs are arranged in front of the
06036 ; PLAYFIELD. The specific order of PLAYERs (PL0..4) and PLAYFIELD colors
06037 ; (PF0..4) is, from front to back:
06038 ;
06039 ; PL0 > PL1 > PL2 > PL3 > PL4 > PF0, PF1, PF2 > PF4 (BGR)
06040 ;
06041 ; In this case, both the starbase and the transfer vessel appear in front of the
06042 ; cross hairs! Suggested fix: None, technically not possible.
06043 ;
06044 ;
06045 ; The starbase is tracked and the PLAYER0..2 shape types are set to STARBASE
06046 ; RIGHT, STARBASE LEFT, and STARBASE CENTER, respectively, combining them into a
06047 ; 3-part starbase shape.
06048 ;
06049 ; If this sector is still marked as a starbase sector but no more so on the
06050 ; Galactic Chart (if in the meantime either Zylon units have surrounded this
06051 ; sector and destroyed the starbase or you have destroyed the starbase with a
06052 ; photon torpedo) then the noise sound pattern SHIELD EXPLOSION is played in
06053 ; subroutine NOISE ($AEA8) and code execution returns.
06054 ;
06055 ; Otherwise a minimum distance to the starbase of +32 (+$0020) <KM> is enforced
06056 ; and the conditions for a successful docking are checked:
06057 ;
06058 ; DOCKING CONDITIONS
06059 ;
06060 ; A docking is successful if all of the following conditions are met:
06061 ;
06062 ; (1) The PLAYER2 (STARBASE CENTER) column number is in 120..135.
06063 ;
06064 ; BUG (at $AD39): At first glance, the PLAYER column interval of 120..135
06065 ; corresponds to an almost symmetric interval of -8..+7 PM pixels relative
06066 ; to the horizontal center of the PLAYFIELD, at PLAYER column number 128
06067 ; (48 PM pixels offset to left PLAYFIELD border + 80 PM pixels to the
06068 ; PLAYFIELD center). This is correct only if the PLAYER column number were
06069 ; to designate the horizontal center of the PLAYER. However it designates
06070 ; its left edge! Thus the used pixel column number range 120..135 creates
06071 ; an asymmetric horizontal docking position: A docking is successful if the
06072 ; horizontal position of the starbase shape's center is roughly -5..+10 PM
06073 ; pixels relative to the horizontal center of the PLAYFIELD. Suggested fix:
06074 ; Replace SBC #120 with SBC #117. This leads to an interval of -8..+7
06075 ; pixels relative to the horizontal center of the PLAYFIELD and better
06076 ; symmetry in the horizontal docking position.
06077 ;
06078 ; (2) The PLAYER2 (STARBASE CENTER) row number is in 104..119.
06079 ;
06080 ; BUG (at $AD43): The PLAYER row interval of 104..119 corresponds to an
06081 ; asymmetric interval of -20..-5 PM pixels relative to the vertical center
06082 ; of the PLAYFIELD, at pixel row number 80 or PLAYER row number 124. It
06083 ; lets you dock at a starbase that "sits" on top of the horizontal cross
06084 ; hairs but not at one that "hangs" from them. Suggested fix: Replace SBC
06085 ; #104 with SBC #108. This leads to an interval of -8..+7 pixels relative
06086 ; to the vertical center of the PLAYFIELD (assuming a PLAYER2 shape of 16
06087 ; pixel height, which is typical during docking) and better symmetry in the
06088 ; vertical docking position.
06089 ;
06090 ; (3) The starbase is in correct distance in front of our starship: The
06091 ; starbase's z-coordinate must be < +512 (+$02**) <KM>.
06092 ;
06093 ; (4) Our starship is horizontally level with the starbase: The starbase's
06094 ; y-coordinate must be < +256 (+$01**) <KM>.
06095 ;
06096 ; (5) Our starship is at a complete halt.
06097 ;
06098 ; DOCKING SUCCESSFUL
06099 ;
06100 ; If the conditions for a successful docking are met, the subsequent docking and
06101 ; transfer operation can be divided in the following states, starting with state
06102 ; NOT DOCKED:
06103 ;
06104 ; (1) NOT DOCKED
06105 ;
06106 ; The docking state is set to ORBIT ESTABLISHED and the title line is
06107 ; updated with "ORBIT ESTABLISHED".
06108 ;
06109 ; (2) ORBIT ESTABLISHED
06110 ;
06111 ; After waiting until the title line "ORBIT ESTABLISHED" has disappeared,
06112 ; the transfer vessel is initialized and launched: The PLAYER4 shape type
06113 ; is set to TRANSFER VESSEL. Its position vector is set to a position above
06114 ; and in front of our starship, but behind the starbase:
06115 ;
06116 ; x-coordinate := +0..+255 (+$00**) <KM>
06117 ; y-coordinate := +256..+511 (+$01**) <KM>
06118 ; z-coordinate := +4096..+4351 (+$10**) <KM>
06119 ;
06120 ; Its velocity vector is set to
06121 ;
06122 ; x-velocity := +1 <KM/H>
06123 ; y-velocity := -1 <KM/H>
06124 ; z-velocity := -7 <KM/H>
06125 ;
06126 ; This will move the transfer vessel from behind the starbase into a
06127 ; direction toward and a little to the lower right of our starship. The
06128 ; lifetime of the transfer vessel (and its return journey) is set to 129
06129 ; game loop iterations. Finally, the docking state is set to RETURN
06130 ; TRANSFER VESSEL.
06131 ;
06132 ; (3) RETURN TRANSFER VESSEL
06133 ;
06134 ; After checking if the transfer vessel has passed behind our starship, the
06135 ; beeper sound pattern ACKNOWLEDGE is played in subroutine BEEP ($B3A6),
06136 ; the title line is updated with "TRANSFER COMPLETE", our starship's
06137 ; subsystems are repaired, and our starship's ENERGY readout is restored to
06138 ; 9999 energy units. by inverting the z-velocity the velocity vector of the
06139 ; transfer vessel is changed to
06140 ;
06141 ; x-velocity := +1 <KM/H>
06142 ; y-velocity := -1 <KM/H>
06143 ; z-velocity := +7 <KM/H>
06144 ;
06145 ; thus launching the transfer vessel on its return journey to the starbase.
06146 ; The docking state is set to TRANSFER COMPLETE. Finally, the screen is
06147 ; updated in subroutine UPDSCREEN ($B07B).
06148 ;
06149 ; (4) TRANSFER COMPLETE
06150 ;
06151 ; This docking state marks the end of a successful docking and transfer
06152 ; operation.
06153 ;
06154 ; DOCKING ABORTED
06155 ;
06156 ; If the docking conditions above are not met and the docking state is already
06157 ; ORBIT ESTABLISHED or RETURN TRANSFER VESSEL then the message "DOCKING ABORTED"
06158 ; is displayed and the docking state is set to NOT DOCKED.
06159
ACE6 A57B 06160 DOCKING LDA ISSTARBASESECT ; Return if not in starbase sector
ACE8 F0FB 06161 BEQ SKIP111 ;
06162
ACEA A5D0 06163 LDA SHIPVIEW ; Skip if not in Front view
ACEC D005 06164 BNE SKIP112 ;
ACEE A914 06165 LDA #$14 ; GTIA: Enable PLAYER4, prio: PFs > PLs > BGR (!)
ACF0 8D1BD0 06166 STA PRIOR ; (Cross hairs in front of PLAYERs)
06167
ACF3 A902 06168 SKIP112 LDA #2 ; Track starbase (PLAYER2)
ACF5 8D5C09 06169 STA TRACKDIGIT ;
06170
06171 ;** Initialize starbase shape **************************************************
ACF8 A930 06172 LDA #SHAP.STARBASEC ; PLAYER2 is STARBASE CENTER (shape type 3)
ACFA 8D8E0C 06173 STA PL2SHAPTYPE ;
ACFD A920 06174 LDA #SHAP.STARBASEL ; PLAYER1 is STARBASE LEFT (shape type 2)
ACFF 8D8D0C 06175 STA PL1SHAPTYPE ;
AD02 A940 06176 LDA #SHAP.STARBASER ; PLAYER0 is STARBASE RIGHT (shape type 4)
AD04 8D8C0C 06177 STA PL0SHAPTYPE ;
06178
AD07 A9FF 06179 LDA #255 ; Prep starbase lifetime := 255 game loops (infinite)
06180
AD09 A690 06181 LDX CURRSECTOR ; Skip if starbase in current sector
AD0B BCC908 06182 LDY GCMEMMAP,X ;
AD0E 3002 06183 BMI SKIP113 ;
06184
AD10 A900 06185 LDA #0 ; Prep starbase lifetime := 0 game loops (fast death)
06186
AD12 85E9 06187 SKIP113 STA PL0LIFE ; PLAYER0 lifetime := either 0 or 255 game loops
AD14 85EA 06188 STA PL1LIFE ; PLAYER1 lifetime := either 0 or 255 game loops
AD16 85EB 06189 STA PL2LIFE ; PLAYER2 lifetime := either 0 or 255 game loops
AD18 857B 06190 STA ISSTARBASESECT ; Store starbase-in-sector flag
AD1A 300A 06191 BMI SKIP114 ; Skip if starbase in current sector
06192
AD1C A002 06193 LDY #2 ; Init explosion at PLAYER2 (STARBASE CENTER)
AD1E 206BAC 06194 JSR INITEXPL ;
06195
AD21 A20A 06196 LDX #$0A ; Play noise sound pattern SHIELD EXPLOSION, return
AD23 4CA8AE 06197 JMP NOISE ;
06198
06199 ;*** Keep minimum distance to starbase *****************************************
AD26 AD420A 06200 SKIP114 LDA PL2ZPOSHI ; Skip if starbase z-coordinate > +255 (+$00**) <KM>
AD29 D00A 06201 BNE SKIP115 ;
06202
AD2B ADD50A 06203 LDA PL2ZPOSLO ; Approach starbase not closer than +32 (+$0020) <KM>
AD2E C920 06204 CMP #32 ;
AD30 B003 06205 BCS SKIP115 ;
AD32 EED50A 06206 INC PL2ZPOSLO ; ...else push starbase back
06207
06208 ;*** Check if in docking range *************************************************
AD35 AD2C0C 06209 SKIP115 LDA PL2COLUMN ; Abort docking if PLAYER column number of...
AD38 38 06210 SEC ; ...PLAYER2 (STARBASE CENTER) not in 120..135.
AD39 E978 06211 SBC #120 ; (!)
AD3B C910 06212 CMP #16 ;
AD3D B022 06213 BCS SKIP116 ;
06214
AD3F ADFB0B 06215 LDA PL2ROWNEW ; Abort docking if PLAYER row number of...
AD42 38 06216 SEC ; ...PLAYER2 (STARBASE CENTER) not in 104..119.
AD43 E968 06217 SBC #104 ; (!)
AD45 C910 06218 CMP #16 ;
AD47 B018 06219 BCS SKIP116 ;
06220
AD49 AD420A 06221 LDA PL2ZPOSHI ; Abort docking if...
AD4C C902 06222 CMP #2 ; ... z-coordinate of starbase >= +512 (+$02**) <KM>
AD4E B011 06223 BCS SKIP116 ;
06224
AD50 ADAF09 06225 LDA PL2ZPOSSIGN ; Abort docking...
AD53 2D110A 06226 AND PL2YPOSSIGN ; ...if starbase not in front and upper screen half
AD56 4901 06227 EOR #$01 ;
AD58 0570 06228 ORA VELOCITYLO ; ...if our starship's velocity not zero
AD5A 0DA40A 06229 ORA PL2YPOSHI ; ...if starbase not roughly vertically centered
AD5D 0571 06230 ORA NEWVELOCITY ; ...if our starship's new velocity not zero
AD5F F010 06231 BEQ SKIP119 ; Else skip and handle docking
06232
06233 ;*** Docking aborted ***********************************************************
AD61 A575 06234 SKIP116 LDA DOCKSTATE ; Skip if DOCKSTATE is NOT DOCKED, TRANSFER COMPLETE
AD63 C902 06235 CMP #2 ;
AD65 9005 06236 BCC SKIP117 ;
06237
AD67 A01F 06238 LDY #$1F ; Set title phrase "DOCKING ABORTED"
AD69 2023B2 06239 JSR SETTITLE ;
06240
AD6C A900 06241 SKIP117 LDA #0 ; DOCKSTATE := NOT DOCKED
AD6E 8575 06242 STA DOCKSTATE ;
AD70 60 06243 SKIP118 RTS ; Return
06244
06245 ;*** Docking successful, check docking state ***********************************
AD71 2475 06246 SKIP119 BIT DOCKSTATE ; Check DOCKSTATE
AD73 700D 06247 BVS SKIP120 ; If DOCKSTATE = ORBIT ESTABLISHED hide title line
AD75 3042 06248 BMI SKIP122 ; If DOCKSTATE = RETURN TRANSFER VESSEL return it
AD77 A575 06249 LDA DOCKSTATE ;
AD79 D0F5 06250 BNE SKIP118 ; Return if DOCKSTATE not NOT DOCKED
AD7B C675 06251 DEC DOCKSTATE ; DOCKSTATE := ORBIT ESTABLISHED
06252
AD7D A01C 06253 LDY #$1C ; Set title phrase "ORBIT ESTABLISHED" and return
AD7F 4C23B2 06254 JMP SETTITLE ;
06255
06256 ;*** Orbit established *********************************************************
AD82 A200 06257 SKIP120 LDX #0 ; Enqueue new, empty title phrase
AD84 8665 06258 STX NEWTITLEPHR ;
06259
AD86 A4D1 06260 LDY TITLEPHR ; Return if "ORBIT ESTABLISHED" still displayed
AD88 D0E6 06261 BNE SKIP118 ;
06262
06263 ;*** Launch transfer vessel ****************************************************
AD8A A950 06264 LDA #SHAP.TRANSVSSL ; PLAYER4 is TRANSFER VESSEL (shape 5)
AD8C 8D900C 06265 STA PL4SHAPTYPE ;
06266
AD8F A901 06267 LDA #1 ; Place transfer vessel behind starbase:
AD91 8DB109 06268 STA PL4ZPOSSIGN ; x-coordinate := +0..+255 (+$00**) <KM>
AD94 8DE209 06269 STA PL4XPOSSIGN ; y-coordinate := +256..+511 (+$01**) <KM>
AD97 8D130A 06270 STA PL4YPOSSIGN ; z-coordinate := +4096..+4351 (+$10**) <KM>
AD9A 8DA60A 06271 STA PL4YPOSHI ;
AD9D 8D9B0B 06272 STA PL4XVEL ; Move transfer vessel toward our starship:
ADA0 A910 06273 LDA #$10 ; x-velocity := +1 <KM/H>
ADA2 8D440A 06274 STA PL4ZPOSHI ; y-velocity := -1 <KM/H>
ADA5 A900 06275 LDA #$00 ; z-velocity := -7 <KM/H>
ADA7 8D750A 06276 STA PL4XPOSHI ;
ADAA A987 06277 LDA #NEG!7 ;
ADAC 8D6A0B 06278 STA PL4ZVEL ;
ADAF A981 06279 LDA #NEG!1 ; DOCKSTATE := RETURN TRANSFER VESSEL
ADB1 8575 06280 STA DOCKSTATE ;
ADB3 8DCC0B 06281 STA PL4YVEL ;
ADB6 85ED 06282 STA PL4LIFE ; Transfer vessel lifetime := 129 game loops
ADB8 60 06283 SKIP121 RTS ; Return
06284
06285 ;*** Return transfer vessel ****************************************************
ADB9 ADB109 06286 SKIP122 LDA PL4ZPOSSIGN ; Return if transfer vessel in front of our starship
ADBC D0FA 06287 BNE SKIP121 ;
06288
ADBE A20C 06289 LDX #$0C ; Play beeper sound pattern ACKNOWLEGDE
ADC0 20A6B3 06290 JSR BEEP ;
06291
ADC3 A021 06292 LDY #$21 ; Set title phrase "TRANSFER COMPLETE"
ADC5 2023B2 06293 JSR SETTITLE ;
06294
ADC8 A205 06295 LDX #5 ; Repair all 6 subsystems
ADCA BD8BBB 06296 LOOP041 LDA PANELTXTTAB+73,X ;
ADCD 9D9209 06297 STA GCSTATPHO,X ;
ADD0 CA 06298 DEX ;
ADD1 10F7 06299 BPL LOOP041 ;
06300
ADD3 A989 06301 LDA #CCS.COL2!CCS.9 ; Set starship's ENERGY readout to "9999" in COLOR2
ADD5 A203 06302 LDX #3 ;
ADD7 9D5509 06303 LOOP042 STA ENERGYD1,X ;
ADDA CA 06304 DEX ;
ADDB 10FA 06305 BPL LOOP042 ;
06306
ADDD A907 06307 LDA #7 ; Move transfer vessel back toward starbase:
ADDF 8D6A0B 06308 STA PL4ZVEL ; x-velocity := -1 <KM/H>
ADE2 A981 06309 LDA #NEG!1 ; y-velocity := +1 <KM/H>
ADE4 8D9B0B 06310 STA PL4XVEL ; z-velocity := +7 <KM/H>
ADE7 A901 06311 LDA #1 ;
ADE9 8DCC0B 06312 STA PL4YVEL ;
06313
ADEC 8575 06314 STA DOCKSTATE ; DOCKSTATE := TRANSFER COMPLETE
ADEE 4C7BB0 06315 JMP UPDSCREEN ; Update screen and return
06316
06317 ;*******************************************************************************
06318 ;* *
06319 ;* MODDLST *
06320 ;* *
06321 ;* Modify Display List *
06322 ;* *
06323 ;*******************************************************************************
06324
06325 ; DESCRIPTION
06326 ;
06327 ; Modifies the Display List to show and hide title, headers, and the Control
06328 ; Panel Display.
06329 ;
06330 ; INPUT
06331 ;
06332 ; A = Number of bytes to copy into the Display List
06333 ; X = Offset into Display List DSPLST ($0280)
06334 ; Y = Offset into Display List fragment table DLSTFRAG ($BA62). If Y = $80
06335 ; then no bytes are copied but the specified locations of the Display List
06336 ; are overwritten with Display List instruction $0D (one row of
06337 ; GRAPHICS7).
06338 ;
06339 ; Used values are:
06340 ;
06341 ; A X Y
06342 ; $08 $5F $00 -> Show Control Panel Display (bottom text window)
06343 ; $08 $5F $80 -> Hide Control Panel Display (bottom text window)
06344 ; $07 $0F $23 -> Show title line
06345 ; $07 $0F $80 -> Hide title line
06346 ; $08 $02 $1B -> Show Display List header line of Front view
06347 ; $08 $02 $13 -> Show Display List header line of Aft view
06348 ; $08 $02 $0B -> Show Display List header line of Long-Range Scan view
06349 ; $08 $02 $08 -> Show Display List header line of Galactic Chart view
06350
=006A 06351 L.NUMBYTES = $6A ; Number of bytes to copy
06352
ADF1 78 06353 MODDLST SEI ; Disable IRQ
ADF2 856A 06354 STA L.NUMBYTES ; Save number of bytes to copy
06355
ADF4 AD0BD4 06356 LOOP043 LDA VCOUNT ; Wait for ANTIC line counter >= 124 (PLAYFIELD...
ADF7 C97C 06357 CMP #124 ; ...bottom) before changing the Display List
ADF9 90F9 06358 BCC LOOP043 ;
06359
ADFB B962BA 06360 LOOP044 LDA DLSTFRAG,Y ; Load byte from Display List fragment table
ADFE C8 06361 INY ;
ADFF 1002 06362 BPL SKIP123 ; Skip if fragment table index < $80
AE01 A90D 06363 LDA #$0D ; Prep Display List instruction $0D (GRAPHICS7)
AE03 9D8002 06364 SKIP123 STA DSPLST,X ; Store byte in Display List
AE06 E8 06365 INX ;
AE07 C66A 06366 DEC L.NUMBYTES ;
AE09 D0F0 06367 BNE LOOP044 ; Copy next byte
06368
AE0B 58 06369 CLI ; Enable IRQ
AE0C 60 06370 RTS ; Return
06371
06372 ;*******************************************************************************
06373 ;* *
06374 ;* CLRPLAYFIELD *
06375 ;* *
06376 ;* Clear PLAYFIELD memory *
06377 ;* *
06378 ;*******************************************************************************
06379
06380 ; DESCRIPTION
06381 ;
06382 ; Clears PLAYFIELD memory from $1000 to $1FFF.
06383 ;
06384 ; This subroutine sets the start address of the memory to be cleared then code
06385 ; execution continues into subroutine CLRMEM ($AE0F) where the memory is
06386 ; actually cleared.
06387
AE0D A910 06388 CLRPLAYFIELD LDA #$10
06389
06390 ;*******************************************************************************
06391 ;* *
06392 ;* CLRMEM *
06393 ;* *
06394 ;* Clear memory *
06395 ;* *
06396 ;*******************************************************************************
06397
06398 ; DESCRIPTION
06399 ;
06400 ; Clears memory from a given start address to memory address $1FFF. This
06401 ; subroutine is called in the following situations:
06402 ;
06403 ; (1) In routine INITCOLD ($A14A) at the beginning of the game to initialize
06404 ; the game's variables
06405 ;
06406 ; (2) In subroutine CLRPLAYFIELD ($AE0D) to clear PLAYFIELD memory.
06407 ;
06408 ; As a side effect this subroutine also clears the saved number of space objects
06409 ; and the lock-on flag.
06410 ;
06411 ; INPUT
06412 ;
06413 ; A = Start address (high byte) of memory to be cleared. Used values are:
06414 ; $02 -> Clear memory $0200..$1FFF during game initialization
06415 ; $10 -> Clear PLAYFIELD memory $1000..$1FFF
06416
AE0F 8569 06417 CLRMEM STA MEMPTR+1 ; Store start address (high byte) to be cleared
AE11 A900 06418 LDA #0 ; Store start address (low byte) to be cleared
AE13 A8 06419 TAY ;
AE14 8568 06420 STA MEMPTR ;
06421
AE16 85A3 06422 STA ISINLOCKON ; Clear lock-on flag
AE18 857A 06423 STA OLDMAXSPCOBJIND ; Clear saved number of space objects
06424
AE1A 9168 06425 LOOP045 STA (MEMPTR),Y ; Clear memory location
AE1C C8 06426 INY ;
AE1D D0FB 06427 BNE LOOP045 ;
06428
AE1F E669 06429 INC MEMPTR+1 ; Next page (= 256-byte block)
AE21 A469 06430 LDY MEMPTR+1 ;
AE23 C020 06431 CPY #$20 ;
AE25 A8 06432 TAY ;
AE26 90F2 06433 BCC LOOP045 ; Loop until memory address $2000 reached
AE28 60 06434 RTS ; Return
06435
06436 ;*******************************************************************************
06437 ;* *
06438 ;* TRIGGER *
06439 ;* *
06440 ;* Handle joystick trigger *
06441 ;* *
06442 ;*******************************************************************************
06443
06444 ; DESCRIPTION
06445 ;
06446 ; This subroutine handles the joystick trigger and launches one of our
06447 ; starship's photon torpedo. If a target is in full lock-on then a second photon
06448 ; torpedo is prepared for automatic launch in the next game loop iteration.
06449 ;
06450 ; DETAILS
06451 ;
06452 ; If the trigger is pressed then reset the idle counter and, if not in
06453 ; hyperwarp, launch a photon torpedo with the following steps:
06454 ;
06455 ; (1) If the trigger was pressed in this game loop iteration, a photon torpedo
06456 ; will be launched if a previously launched photon torpedo is already under
06457 ; way for at least 255 - 232 = 23 game loop iterations. This avoids firing
06458 ; photon torpedoes too rapidly.
06459 ;
06460 ; (2) Start tracking a space object. If it is in full lock-on, set up the
06461 ; lock-on timer, activate photon torpedo tracking, and tweak the last saved
06462 ; trigger state such that our other photon torpedo (if available) is
06463 ; launched automatically in the next game loop iteration.
06464 ;
06465 ; (3) If the Photon Torpedoes are destroyed, do nothing.
06466 ;
06467 ; (4) If the Photon Torpedoes are damaged, launch a photon torpedo from the
06468 ; same barrel than the previous one.
06469 ;
06470 ; (5) If the Photon Torpedoes are not damaged, launch a photon torpedo from the
06471 ; other barrel.
06472 ;
06473 ; (6) Set the lifetime of our starship's photon torpedo to infinite, set the
06474 ; PLAYER shape to PHOTON TORPEDO.
06475 ;
06476 ; (7) Initialize the position vector of our starship's photon torpedo to:
06477 ;
06478 ; x-coordinate := +256 (+$0100) <KM> (Right barrel)
06479 ; -256 (-$FF00) <KM> (Left barrel)
06480 ; y-coordinate := -256 (-$FF00) <KM>
06481 ; z-coordinate := +1 (+$0001) <KM>
06482 ;
06483 ; (8) Initialize the velocity vector of our starship's photon torpedo to:
06484 ;
06485 ; x-velocity := +0 <KM/H>
06486 ; y-velocity := +0 <KM/H>
06487 ; z-velocity := +102 <KM/H> (All views but Aft view)
06488 ; -102 <KM/H> (Aft view)
06489 ;
06490 ; (9) Subtract 10 energy units for launching our starship's photon torpedo.
06491 ;
06492 ; (10) Play the noise sound pattern PHOTON TORPEDO LAUNCHED by continuing code
06493 ; execution into subroutine NOISE ($AEA8).
06494
AE29 A584 06495 TRIGGER LDA OLDTRIG0 ; Prep last trigger state
06496
AE2B AC10D0 06497 LDY TRIG0 ; Copy current trigger state
AE2E 8484 06498 STY OLDTRIG0 ;
AE30 D00E 06499 BNE SKIP124 ; Return if trigger currently not pressed
06500
AE32 8466 06501 STY IDLECNTHI ; Reset idle counter
06502
AE34 A6C0 06503 LDX WARPSTATE ; Return if hyperwarp engaged
AE36 D008 06504 BNE SKIP124 ;
06505
AE38 A687 06506 LDX BARRELNR ; Prep barrel number (0 -> left, 1 -> right)
06507
AE3A C901 06508 CMP #1 ; If trigger is newly pressed -> handle tracking...
AE3C F003 06509 BEQ SKIP125 ; ...and launch our starship's photon torpedo...
AE3E B018 06510 BCS SKIP127 ; ...else launch our starship's photon torpedo only
AE40 60 06511 SKIP124 RTS ; Return
06512
06513 ;*** Set up our starship's photon torpedo tracking *****************************
AE41 B5EC 06514 SKIP125 LDA PL3LIFE,X ; Return if torpedo's lifetime >= 232 game loops
AE43 C9E8 06515 CMP #232 ;
AE45 B0F9 06516 BCS SKIP124 ;
06517
AE47 AC5C09 06518 LDY TRACKDIGIT ; Store index of tracked space object
AE4A 8489 06519 STY PLTRACKED ;
06520
AE4C A90C 06521 LDA #12 ; Prep lock-on lifetime := 12 game loops
AE4E A4A3 06522 LDY ISINLOCKON ; If target is in full lock-on...
AE50 8486 06523 STY ISTRACKING ; ...activate photon torpedo tracking
06524
AE52 F002 06525 BEQ SKIP126 ; Skip if target not in full lock-on
AE54 A900 06526 LDA #0 ; Prep lock-on lifetime := 0 game loops
AE56 8588 06527 SKIP126 STA LOCKONLIFE ; Store lock-on lifetime (either 0 or 12 game loops)
06528
06529 ;*** Launch our starship's photon torpedo **************************************
AE58 8484 06530 SKIP127 STY OLDTRIG0 ; Update last trigger state
AE5A 2C9209 06531 BIT GCSTATPHO ; Return if Photon Torpedoes are destroyed
AE5D 70E1 06532 BVS SKIP124 ;
06533
AE5F 3005 06534 BMI SKIP128 ; If Photon Torpedoes damaged launch from same barrel
AE61 8A 06535 TXA ; ...else switch barrel from which to launch torpedo
AE62 4901 06536 EOR #$01 ;
AE64 8587 06537 STA BARRELNR ;
06538
AE66 8A 06539 SKIP128 TXA ; SUMMARY: Our starship's photon torpedo's...
AE67 9DE109 06540 STA PL3XPOSSIGN,X ; x-coordinate := +256 (+$0100) <KM> (right barrel)
AE6A BD73BF 06541 LDA BARRELXTAB,X ; x-coordinate := -256 (-$FF00) <KM> (left barrel)
AE6D 9D740A 06542 STA PL3XPOSHI,X ; y-coordinate := -256 (-$FF00) <KM>
AE70 A9FF 06543 LDA #255 ; z-coordinate := +1 (+$0001) <KM>
AE72 95EC 06544 STA PL3LIFE,X ; ...lifetime := 255 game loops
AE74 9DA50A 06545 STA PL3YPOSHI,X ;
AE77 A900 06546 LDA #0 ;
AE79 9D8F0C 06547 STA PL3SHAPTYPE,X ; PLAYER3 or PLAYER4 is PHOTON TORPEDO (shape type 0)
AE7C 9D430A 06548 STA PL3ZPOSHI,X ;
AE7F 9D070B 06549 STA PL3XPOSLO,X ;
AE82 9D120A 06550 STA PL3YPOSSIGN,X ;
AE85 9D380B 06551 STA PL3YPOSLO,X ;
AE88 A901 06552 LDA #1 ;
AE8A 9DB009 06553 STA PL3ZPOSSIGN,X ;
AE8D 9DD60A 06554 STA PL3ZPOSLO,X ;
06555
AE90 A5D0 06556 LDA SHIPVIEW ; SUMMARY: Our starship's photon torpedo's...
AE92 4A 06557 LSR A ; x-velocity := +0 <KM/H>
AE93 6A 06558 ROR A ; y-velocity := +0 <KM/H>
AE94 0966 06559 ORA #102 ; z-velocity := +102 <KM/H> (Other views)
AE96 9D690B 06560 STA PL3ZVEL,X ; z-velocity := -102 <KM/H> (Aft view)
AE99 A900 06561 LDA #0 ;
AE9B 9D9A0B 06562 STA PL3XVEL,X ;
AE9E 9DCB0B 06563 STA PL3YVEL,X ;
06564
AEA1 A202 06565 LDX #2 ; ENERGY := ENERGY - 10 for launching photon torpedo
AEA3 206FB8 06566 JSR DECENERGY ;
06567
AEA6 A200 06568 LDX #$00 ; Play noise sound pattern PHOTON TORPEDO LAUNCHED
06569
06570 ;*******************************************************************************
06571 ;* *
06572 ;* NOISE *
06573 ;* *
06574 ;* Copy noise sound pattern *
06575 ;* *
06576 ;*******************************************************************************
06577
06578 ; DESCRIPTION
06579 ;
06580 ; Copies a 10-byte noise sound pattern from table NOISEPATTAB ($BF20). The first
06581 ; 8 bytes are copied to the noise sound pattern area NOISETORPTIM
06582 ; ($DA)..NOISELIFE ($E1), the remaining 2 bytes are copied to audio registers
06583 ; AUDCTL ($D208) and AUDF3 ($D204). The noise sound pattern is automatically
06584 ; played in subroutine SOUND ($B2AB).
06585 ;
06586 ; NOTE: The first 8 bytes of each pattern in table NOISEPATTAB ($BF20) are
06587 ; copied in reverse order from memory. See subroutine SOUND ($B2AB) for details
06588 ; on the noise sound patterns stored in NOISEPATTAB ($BF20).
06589 ;
06590 ; Playing a SHIELD EXPLOSION or ZYLON EXPLOSION noise sound pattern overrides a
06591 ; currently playing PHOTON TORPEDO LAUNCHED noise sound pattern.
06592 ;
06593 ; Playing a PHOTON TORPEDO LAUNCHED noise sound pattern overrides a currently
06594 ; playing PHOTON TORPEDO LAUNCHED noise sound pattern if the latter has < 24
06595 ; TICKs to play.
06596 ;
06597 ; INPUT
06598 ;
06599 ; X = Offset into table NOISEPATTAB ($BF20) to index noise sound patterns.
06600 ; Used values are:
06601 ; $00 -> PHOTON TORPEDO LAUNCHED
06602 ; $0A -> SHIELD EXPLOSION (either our starship or a starbase explodes)
06603 ; $14 -> ZYLON EXPLOSION
06604
AEA8 8A 06605 NOISE TXA ; Skip if SHIELD EXPLOSION or ZYLON EXPLOSION playing
AEA9 D006 06606 BNE SKIP129 ;
06607
AEAB A5E1 06608 LDA NOISELIFE ; Return if PHOTON TORPEDO LAUNCHED noise sound pat.
AEAD C918 06609 CMP #24 ; ...playing for yet more than 24 TICKs
AEAF B018 06610 BCS SKIP130 ;
06611
AEB1 A007 06612 SKIP129 LDY #7 ; Copy noise sound pattern (in reverse order)
AEB3 BD20BF 06613 LOOP046 LDA NOISEPATTAB,X ;
AEB6 99DA00 06614 STA NOISETORPTIM,Y ;
AEB9 E8 06615 INX ;
AEBA 88 06616 DEY ;
AEBB 10F6 06617 BPL LOOP046 ;
06618
AEBD BD20BF 06619 LDA NOISEPATTAB,X ; Copy AUDCTL from noise sound pattern table
AEC0 8D08D2 06620 STA AUDCTL ;
AEC3 BD21BF 06621 LDA NOISEPATTAB+1,X ; Copy AUDF3 from noise sound pattern table
AEC6 8D04D2 06622 STA AUDF3 ;
06623
AEC9 60 06624 SKIP130 RTS ; Return
06625
06626 ;*******************************************************************************
06627 ;* *
06628 ;* HOMINGVEL *
06629 ;* *
06630 ;* Calculate homing velocity of our starship's photon torpedo 0 or 1 *
06631 ;* *
06632 ;*******************************************************************************
06633
06634 ; DESCRIPTION
06635 ;
06636 ; Calculates the x (or y) velocity vector component of our starship's photon
06637 ; torpedo 0 or 1 when it is tracking (homing in on) a target space object.
06638 ;
06639 ; Our starship's photon torpedo's x (or y) velocity vector component depends on
06640 ; the PLAYER column (or row) number difference between the target PLAYER and our
06641 ; starship's photon torpedo PLAYER in Player/Missile (PM) pixels. This
06642 ; difference is used as an index to pick the new x (or y) velocity vector
06643 ; component of our starship's photon torpedo from table HOMVELTAB ($BFC9):
06644 ;
06645 ; +---------------+--------------+
06646 ; | Difference in | New Velocity |
06647 ; | PM Pixels | Component |
06648 ; +---------------+--------------+
06649 ; | >= +7 | -64 <KM/H> |
06650 ; | +6 | -56 <KM/H> |
06651 ; | +5 | -48 <KM/H> |
06652 ; | +4 | -40 <KM/H> |
06653 ; | +3 | -24 <KM/H> |
06654 ; | +2 | -16 <KM/H> |
06655 ; | +1 | -8 <KM/H> |
06656 ; | 0 | 0 <KM/H> |
06657 ; | -1 | +8 <KM/H> |
06658 ; | -2 | +16 <KM/H> |
06659 ; | -3 | +24 <KM/H> |
06660 ; | -4 | +40 <KM/H> |
06661 ; | -5 | +48 <KM/H> |
06662 ; | -6 | +56 <KM/H> |
06663 ; | <= -7 | +64 <KM/H> |
06664 ; +---------------+--------------+
06665 ;
06666 ; INPUT
06667 ;
06668 ; A = PLAYER column (or row) number difference between the target PLAYER
06669 ; and our starship's photon torpedo PLAYER in Player/Missile pixels
06670 ;
06671 ; CARRY = Sign of the PLAYER column (or row) number difference. Used values
06672 ; are:
06673 ; 0 -> Negative difference (target PLAYER column (or row) number < our
06674 ; starship's photon torpedo PLAYER column (or row) number
06675 ; 1 -> Positive difference (target PLAYER column (or row) number >= our
06676 ; starship's photon torpedo PLAYER column (or row) number
06677 ;
06678 ; OUTPUT
06679 ;
06680 ; A = New velocity vector component of our starship's photon torpedo in <KM/H>
06681
=006A 06682 L.VELSIGN = $6A ; Saves velocity sign
06683
AECA A080 06684 HOMINGVEL LDY #NEG ; Preload negative velocity sign
AECC B004 06685 BCS SKIP131 ; Skip if difference is positive
06686
AECE 49FF 06687 EOR #$FF ; Invert to get absolute value of difference
AED0 A000 06688 LDY #0 ; Preload positive velocity sign
06689
AED2 846A 06690 SKIP131 STY L.VELSIGN ; Save velocity sign
AED4 C908 06691 CMP #8 ;
AED6 9002 06692 BCC SKIP132 ;
AED8 A907 06693 LDA #7 ; Limit difference to 0..7
AEDA A8 06694 SKIP132 TAY ;
AEDB A56A 06695 LDA L.VELSIGN ; Reload velocity sign
AEDD 19C9BF 06696 ORA HOMVELTAB,Y ; Combine with homing velocity from table
AEE0 60 06697 RTS ; Return
06698
06699 ;*******************************************************************************
06700 ;* *
06701 ;* DAMAGE *
06702 ;* *
06703 ;* Damage or destroy one of our starship's subsystems *
06704 ;* *
06705 ;*******************************************************************************
06706
06707 ; DESCRIPTION
06708 ;
06709 ; Damages or destroys one of our starship's subsystems. There are 6 subsystems:
06710 ;
06711 ; (1) Photon Torpedoes
06712 ; (2) Engines
06713 ; (3) Shields
06714 ; (4) Attack Computer
06715 ; (5) Long-Range Scan
06716 ; (6) Subspace Radio
06717 ;
06718 ; Their status is stored and displayed in the Galactic Chart Panel Display by
06719 ; the colored letters PESCLR. The color of each letter represents the
06720 ; subsystem's status:
06721 ;
06722 ; +---------------+------------------+
06723 ; | Letter Color | Subsystem Status |
06724 ; +---------------+------------------+
06725 ; | {LIGHT GREEN} | OK |
06726 ; | {CORN YELLOW} | Damaged |
06727 ; | {PINK} | Destroyed |
06728 ; +---------------+------------------+
06729 ;
06730 ; This subroutine first makes sure that we are not in demo mode. Then it picks a
06731 ; random value in 0..255 and the damage probability value. The latter value
06732 ; depends on the mission level and is picked from table DAMAGEPROBTAB ($BF10):
06733 ;
06734 ; +-----------+-------------------+---------------+
06735 ; | Mission | Damage | Damage |
06736 ; | Level | Probability Value | Probability |
06737 ; +-----------+-------------------+---------------+
06738 ; | NOVICE | 0 | 0% ( 0:256) |
06739 ; | PILOT | 80 | 31% ( 80:256) |
06740 ; | WARRIOR | 180 | 70% (180:256) |
06741 ; | COMMANDER | 254 | 99% (254:256) |
06742 ; +-----------+-------------------+---------------+
06743 ;
06744 ; If the random number is lower than the damage probability value, a randomly
06745 ; picked subsystem is about to get damaged (or destroyed). There is a built-in
06746 ; upfront probability of 25% (2:8) that no subsystem gets harmed.
06747 ;
06748 ; If the picked subsystem is already destroyed then another subsystem is picked.
06749 ;
06750 ; Then the title phrase offset is picked from table DAMAGEPHRTAB ($BF14) to
06751 ; display the damaged subsystem in the title line. Next, color bits are picked
06752 ; that indicate a damaged system.
06753 ;
06754 ; If the Zylon photon torpedo's lifetime >= 30 game loop iterations the
06755 ; subsystem will not only be damaged but destroyed.
06756 ;
06757 ; NOTE: The Zylon photon torpedo lifetime decreases from 62 to 0 game loop
06758 ; iterations. With a remaining lifetime >= 30 game loop iterations it is
06759 ; considered strong enough to destroy one of our starship's subsystems. There
06760 ; are two exceptions to this rule: If the Attack Computer was picked to be
06761 ; destroyed it will be damaged only - not destroyed - if the Long-Range Scan has
06762 ; been already destroyed, and vice versa.
06763 ;
06764 ; Then the title phrase offset from table DESTROYPHRTAB ($BF1A) is picked to
06765 ; display the destroyed subsystem in the title line. Next, color bits are picked
06766 ; that indicate a destroyed system.
06767 ;
06768 ; The color of the subsystem's status letter is adjusted in the Galactic Chart
06769 ; Panel Display. Next, the title phrase describing the subsystem's status is
06770 ; enqueued for display in the title line. If the Attack Computer has been
06771 ; destroyed it is switched off and the PLAYFIELD is cleared. The title line is
06772 ; updated with the "DAMAGE CONTROL" message. Finally, the beeper sound pattern
06773 ; DAMAGE REPORT is played in subroutine BEEP ($B3A6).
06774
AEE1 2464 06775 DAMAGE BIT ISDEMOMODE ; Return if in demo mode
AEE3 3057 06776 BMI SKIP137 ;
06777
06778 ;*** Damage some subsystem *****************************************************
AEE5 A662 06779 LDX MISSIONLEVEL ; Prep mission level
AEE7 AD0AD2 06780 LOOP047 LDA RANDOM ; Return if random number >= damage probability
AEEA DD10BF 06781 CMP DAMAGEPROBTAB,X ; ...(the latter depends on mission level)
AEED B04D 06782 BCS SKIP137 ;
06783
AEEF 2907 06784 AND #$07 ; Randomly pick 1 of 6 subsystems
AEF1 C906 06785 CMP #6 ; Return if no subsystem picked
AEF3 B047 06786 BCS SKIP137 ;
06787
AEF5 AA 06788 TAX ;
AEF6 BD9209 06789 LDA GCSTATPHO,X ; Get picked subsystem status letter
AEF9 0A 06790 ASL A ; Check bit B6 (= destroyed) of letter code
AEFA 30EB 06791 BMI LOOP047 ; Try again if subsystem already destroyed
06792
AEFC A5EB 06793 LDA PL2LIFE ; Load Zylon photon torpedo lifetime...
AEFE C91E 06794 CMP #30 ; ...and compare it to 30 game loops
06795
AF00 A980 06796 LDA #CCS.COL2 ; Preload COLOR2 text color bits (= damaged status)
AF02 BC14BF 06797 LDY DAMAGEPHRTAB,X ; Preload title phrase offset of damaged subsystem
06798
AF05 9017 06799 BCC SKIP135 ; Skip if Zylon torpedo lifetime < 30 game loops
06800
AF07 E003 06801 CPX #3 ; Skip if selected subsystem not Attack Computer
AF09 D005 06802 BNE SKIP133 ;
AF0B 2C9609 06803 BIT GCSTATLRS ; Skip if Long-Range Scan already destroyed
AF0E 700E 06804 BVS SKIP135 ;
AF10 E004 06805 SKIP133 CPX #4 ; Skip if selected subsystem is not Long-Range Scan
AF12 D005 06806 BNE SKIP134 ;
AF14 2C9509 06807 BIT GCSTATCOM ; Skip if Attack Computer already destroyed
AF17 7005 06808 BVS SKIP135 ;
06809
AF19 A9C0 06810 SKIP134 LDA #CCS.COL3 ; Preload COLOR3 text color bits (= destroyed status)
AF1B BC1ABF 06811 LDY DESTROYPHRTAB,X ; Preload title phrase offset of destroyed subsystem
06812
AF1E 1D9209 06813 SKIP135 ORA GCSTATPHO,X ; Combine status letter with new color
AF21 9D9209 06814 STA GCSTATPHO,X ;
AF24 8465 06815 STY NEWTITLEPHR ; Enqueue damage status title phrase
AF26 2C9509 06816 BIT GCSTATCOM ; Skip if Attack Computer OK or damaged
AF29 5007 06817 BVC SKIP136 ;
06818
AF2B A900 06819 LDA #0 ; Switch Attack Computer off
AF2D 857E 06820 STA DRAINATTCOMP ;
AF2F 200DAE 06821 JSR CLRPLAYFIELD ; Clear PLAYFIELD
06822
AF32 A052 06823 SKIP136 LDY #$52 ; Set title phrase "DAMAGE CONTROL..."
AF34 2023B2 06824 JSR SETTITLE ;
06825
AF37 A212 06826 LDX #$12 ; Play beeper sound pattern DAMAGE REPORT
AF39 20A6B3 06827 JSR BEEP ;
06828
AF3C 60 06829 SKIP137 RTS ; Return
06830
06831 ;*******************************************************************************
06832 ;* *
06833 ;* COLLISION *
06834 ;* *
06835 ;* Detect a collision of our starship's photon torpedoes *
06836 ;* *
06837 ;*******************************************************************************
06838
06839 ; DESCRIPTION
06840 ;
06841 ; Both of our starship's photon torpedoes are checked if they have collided with
06842 ; a space object represented by PLAYER0..2, such as a Zylon ship, a Zylon photon
06843 ; torpedo, a starbase, or a meteor.
06844 ;
06845 ; For quick lookup, the following table lists the PLAYERs and what space objects
06846 ; they represent:
06847 ;
06848 ; +--------+--------------------------------------------------+
06849 ; | PLAYER | Represents |
06850 ; +--------+--------------------------------------------------+
06851 ; | 0 | Zylon ship 0, Starbase Left |
06852 ; | 1 | Zylon ship 1, Starbase Right |
06853 ; | 2 | Zylon photon torpedo, Starbase Center, Meteor |
06854 ; | 3 | Our starship's photon torpedo 0 |
06855 ; | 4 | Our starship's photon torpedo 1, Transfer Vessel |
06856 ; +--------+--------------------------------------------------+
06857 ;
06858 ; NOTE: Only space objects represented by PLAYER0..2 are checked for collisions.
06859 ; The transfer vessel of the starbase, represented by PLAYER4, is not checked
06860 ; and therefore cannot be destroyed by one of our starship's photon torpedoes.
06861 ;
06862 ; This subroutine first checks if our starship's photon torpedoes are
06863 ; represented by alive PLAYERs with PHOTON TORPEDO shape.
06864 ;
06865 ; In order to detect a collision with a space object, our starship's photon
06866 ; torpedo must compare its x, y, and z coordinates with the ones of the space
06867 ; object.
06868 ;
06869 ; Instead of comparing the x and y coordinates, however, this subroutines uses a
06870 ; much more efficient method by inspecting the Player/Missile collision
06871 ; registers, as the x and y axis of the 3D coordinate system establish the plane
06872 ; in which the TV screen lies. Each of our starship's photon torpedoes has its
06873 ; own Player/Missile collision register: PL3HIT ($82) for our starship's photon
06874 ; torpedo 0 and PL4HIT ($83) for our starship's photon torpedo 1. By inspecting
06875 ; these registers the hit space object is determined:
06876 ;
06877 ; +---------------------------------------------------+-------------------------+
06878 ; | Bits B2..0 of Collision Register | Hit PLAYER |
06879 ; | (0 -> Not Hit, 1 -> Hit) | |
06880 ; +-----------------+----------------+----------------+ |
06881 ; | PLAYER2 | PLAYER1 | PLAYER0 | |
06882 ; | (Zylon torpedo) | (Zylon ship 1) | (Zylon ship 0) | |
06883 ; +-----------------+----------------+----------------+-------------------------+
06884 ; | 0 | 0 | 0 | None |
06885 ; | 0 | 0 | 1 | PLAYER0 (Zylon ship 0) |
06886 ; | 0 | 1 | 0 | PLAYER1 (Zylon ship 1) |
06887 ; | 0 | 1 | 1 | PLAYER1 (Zylon ship 1) |
06888 ; | 1 | 0 | 0 | PLAYER2 (Zylon torpedo) |
06889 ; | 1 | 0 | 1 | PLAYER2 (Zylon torpedo) |
06890 ; | 1 | 1 | 0 | PLAYER1 (Zylon ship 1) |
06891 ; | 1 | 1 | 1 | PLAYER1 (Zylon ship 1) |
06892 ; +-----------------+----------------+----------------+-------------------------+
06893 ;
06894 ; If the lifetime of the hit space object has already expired, then the hit is
06895 ; ignored.
06896 ;
06897 ; A collision along the z-axis happens if the z-coordinate of our starship's
06898 ; photon torpedo is close enough to the z-coordinate of the space object. This
06899 ; is determined as follows:
06900 ;
06901 ; The absolute value of the z-coordinate of the space object is converted into a
06902 ; range index in 0..7. This index picks a minimum and a maximum z-coordinate
06903 ; from tables HITMINZTAB ($BF7D) and HITMAXZTAB ($BF75). If the absolute value
06904 ; of the z-coordinate of our starship's photon torpedo is inside this interval,
06905 ; then our starship's photon torpedo has hit the space object. The following
06906 ; table lists the relevant values:
06907 ;
06908 ; +-----------------------+-------+--------------------------+--------------------------+
06909 ; | ABS(z-Coordinate) | Range | Min ABS(z-Coordinate) | Max ABS(z-Coordinate) |
06910 ; | of Space Object | Index | of Photon Torpedo to Hit | of Photon Torpedo to Hit |
06911 ; +-----------------------+-------+--------------------------+--------------------------+
06912 ; | <= 511 ($01**) <KM> | 0 | 0 ($00**) <KM> | < 3328 ($0C**) <KM> |
06913 ; | <= 1023 ($03**) <KM> | 1 | 0 ($00**) <KM> | < 3328 ($0C**) <KM> |
06914 ; | <= 1535 ($05**) <KM> | 2 | 0 ($00**) <KM> | < 3328 ($0C**) <KM> |
06915 ; | <= 2047 ($07**) <KM> | 3 | 512 ($02**) <KM> | < 3328 ($0C**) <KM> |
06916 ; | <= 2559 ($09**) <KM> | 4 | 1024 ($04**) <KM> | < 3840 ($0E**) <KM> |
06917 ; | <= 3071 ($0B**) <KM> | 5 | 1536 ($06**) <KM> | < 3840 ($0E**) <KM> |
06918 ; | <= 3583 ($0D**) <KM> | 6 | 2048 ($08**) <KM> | < 3840 ($0E**) <KM> |
06919 ; | <= 65535 ($FF**) <KM> | 7 | 3072 ($0C**) <KM> | < 8448 ($20**) <KM> |
06920 ; +-----------------------+-------+--------------------------+--------------------------+
06921 ;
06922 ; If a collision has been detected, the "age" (= initial lifetime - remaining
06923 ; lifetime) of our starship's photon torpedo is calculated. This age is used to
06924 ; delay playing the ZYLON EXPLOSION noise sound pattern. It is also used to
06925 ; determine the strength of our starship's photon torpedo. Only photon torpedoes
06926 ; of an age < 15 game loop iterations can destroy a Zylon basestar.
06927 ;
06928 ; Some clean-up work is done before the actual explosion: The lock-on timer, our
06929 ; starship's photon torpedo lifetime, and the hit space object's PLAYER lifetime
06930 ; is set to 0.
06931 ;
06932 ; If a meteor or a Zylon photon torpedo have been hit, then the score is not
06933 ; changed, skipping right to the explosion part. Otherwise, our starship's
06934 ; photon torpedo tracking flag is cleared and the Galactic Chart Map is updated.
06935 ; If a starbase was destroyed, then 3 points are subtracted from the score. If a
06936 ; Zylon ship was destroyed, then 6 points are added to the score and the Zylon
06937 ; KILL COUNTER readout of the Control Panel Display is incremented. Next, the
06938 ; explosion is initialized in subroutine INITEXPL ($AC6B).
06939 ;
06940 ; NOTE: This subroutine lacks proper explosion initialization if the starbase
06941 ; was hit. The actual explosion initialization is done in subroutine DOCKING
06942 ; ($ACE6) when the code finds out that the starbase sector is no more marked as
06943 ; such in the Galactic Chart.
06944 ;
06945 ; Finally, the Galactic Chart Map is searched for a remaining Zylon unit. If
06946 ; none is found then the mission is complete and code execution continues into
06947 ; subroutine GAMEOVER2 ($B121), ending the game.
06948
=006B 06949 L.PLHIT = $6B ; Saves PLAYER (and space object) index of hit PLAYER
=006C 06950 L.VIEWDIR = $6C ; Saves view direction. Used values are:
06951 ; $00 -> Front view
06952 ; $FF -> Aft view
06953
AF3D A202 06954 COLLISION LDX #2 ; Loop over our starship's two photon torpedoes
AF3F CA 06955 LOOP048 DEX ;
AF40 1001 06956 BPL SKIP138 ; Branch into loop body below
AF42 60 06957 RTS ; Return
06958
06959 ;*** Photon torpedo sanity checks **********************************************
AF43 BD8F0C 06960 SKIP138 LDA PL3SHAPTYPE,X ; Next photon torpedo if PLAYER not a PHOTON TORPEDO
AF46 D0F7 06961 BNE LOOP048 ;
06962
AF48 B5EC 06963 LDA PL3LIFE,X ; Next photon torpedo if PLAYER not alive
AF4A F0F3 06964 BEQ LOOP048 ;
06965
06966 ;*** Check if our starship's photon torpedo has hit in x-y plane ***************
AF4C B582 06967 LDA PL3HIT,X ; Check Player/Missile collision register
AF4E 2907 06968 AND #$07 ; Next torpedo if no torpedo-to-PLAYER collision
AF50 F0ED 06969 BEQ LOOP048 ;
06970
AF52 4A 06971 LSR A ; Find out which of PLAYER0..2 was hit in PLAYFIELD
AF53 C903 06972 CMP #3 ;
AF55 D001 06973 BNE SKIP139 ;
AF57 4A 06974 LSR A ;
AF58 A8 06975 SKIP139 TAY ; Save resulting index of hit PLAYER
06976
AF59 B9E900 06977 LDA PL0LIFE,Y ; Next torpedo if PLAYER0..2 (= targets) not alive
AF5C F0E1 06978 BEQ LOOP048 ;
06979
06980 ;*** Has our starship's photon torpedo hit within valid z-coordinate interval? *
AF5E A5D0 06981 LDA SHIPVIEW ; Skip if in Front view
AF60 F002 06982 BEQ SKIP140 ;
AF62 A9FF 06983 LDA #$FF ; Calculate range index...
AF64 856C 06984 SKIP140 STA L.VIEWDIR ; Saves view direction
AF66 59400A 06985 EOR ZPOSHI,Y ; Calc ABS(z-coordinate (high byte)) of hit object
AF69 C910 06986 CMP #16 ; Limit range index to 0..7
AF6B 9002 06987 BCC SKIP141 ;
AF6D A90F 06988 LDA #15 ;
AF6F 4A 06989 SKIP141 LSR A ;
AF70 846B 06990 STY L.PLHIT ; Save index of hit PLAYER
06991
AF72 A8 06992 TAY ;
AF73 A56C 06993 LDA L.VIEWDIR ; Reload view direction
AF75 5D430A 06994 EOR PL3ZPOSHI,X ; Calc ABS(z-coordinate (high byte)) of torpedo
06995
AF78 D975BF 06996 CMP HITMAXZTAB,Y ; Next torpedo if torpedo >= max hit z-coordinate
AF7B B0C2 06997 BCS LOOP048 ;
06998
AF7D D97DBF 06999 CMP HITMINZTAB,Y ; Next torpedo if torpedo < min hit z-coordinate
AF80 90BD 07000 BCC LOOP048 ;
07001
07002 ;*** Our starship's photon torpedo has hit within valid z-coordinate interval! *
AF82 A46B 07003 LDY L.PLHIT ; Reload index of hit PLAYER
AF84 38 07004 SEC ; Calc "age" of photon torpedo in game loops to...
AF85 A9FF 07005 LDA #255 ; delay playing ZYLON EXPLOSION noise sound pattern
AF87 F5EC 07006 SBC PL3LIFE,X ;
AF89 85E2 07007 STA NOISEZYLONTIM ;
07008
AF8B C90F 07009 CMP #15 ; Skip if photon torpedo "age" < 15
AF8D 9005 07010 BCC SKIP142 ;
AF8F B98C0C 07011 LDA PL0SHAPTYPE,Y ; CARRY := PLAYER is ZYLON BASESTAR (shape type 8)
AF92 C980 07012 CMP #SHAP.ZBASESTAR ; (and torpedo "age" good to destroy ZYLON BASESTAR)
07013
07014 ;*** Clean up our starship's photon torpedo and hit PLAYER *********************
AF94 A900 07015 SKIP142 LDA #0 ; Lock-on lifetime := 0 game loops
AF96 8588 07016 STA LOCKONLIFE ;
AF98 95EC 07017 STA PL3LIFE,X ; Photon torpedo's lifetime := 0 game loops
AF9A B04B 07018 BCS SKIP144 ; If CARRY set do not score, just do explosion
07019
AF9C 99E900 07020 STA PL0LIFE,Y ; Hit PLAYER lifetime := 0 game loops
07021
AF9F B98C0C 07022 LDA PL0SHAPTYPE,Y ; If hit PLAYER is...
AFA2 F043 07023 BEQ SKIP144 ; ...a PHOTON TORPEDO (shape type 0)...
AFA4 C960 07024 CMP #SHAP.METEOR ; ...or a METEOR (shape type 6)...
AFA6 F03F 07025 BEQ SKIP144 ; ...do not score, just do explosion
07026
AFA8 A900 07027 LDA #0 ; Clear photon torpedo tracking flag
AFAA 8586 07028 STA ISTRACKING ;
07029
07030 ;*** Zylon ship (or starbase) destroyed! ***************************************
AFAC A690 07031 LDX CURRSECTOR ; Decrement Zylon count on Galactic Chart
AFAE DEC908 07032 DEC GCMEMMAP,X ;
AFB1 1013 07033 BPL SKIP143 ; Skip if destroyed space object was Zylon ship
07034
07035 ;*** Starbase destroyed! *******************************************************
AFB3 A900 07036 LDA #0 ; Remove destroyed starbase from Galactic Chart
AFB5 9DC908 07037 STA GCMEMMAP,X ;
AFB8 38 07038 SEC ; SCORE := SCORE - 3 for destroying starbase
AFB9 A5CB 07039 LDA SCORE ;
AFBB E903 07040 SBC #3 ;
AFBD 85CB 07041 STA SCORE ;
AFBF A5CC 07042 LDA SCORE+1 ;
AFC1 E900 07043 SBC #0 ;
AFC3 85CC 07044 STA SCORE+1 ;
AFC5 60 07045 RTS ; Return
07046
07047 ;*** Zylon ship destroyed! *****************************************************
AFC6 18 07048 SKIP143 CLC ; SCORE := SCORE + 6 for destroying Zylon ship
AFC7 A5CB 07049 LDA SCORE ;
AFC9 6906 07050 ADC #6 ;
AFCB 85CB 07051 STA SCORE ;
AFCD A5CC 07052 LDA SCORE+1 ;
AFCF 6900 07053 ADC #0 ;
AFD1 85CC 07054 STA SCORE+1 ;
07055
AFD3 A201 07056 LDX #1 ; Increment Zylon KILL COUNTER readout...
AFD5 FE5009 07057 LOOP049 INC KILLCNTD1,X ; ...of Control Panel Display
AFD8 BD5009 07058 LDA KILLCNTD1,X ;
AFDB C94A 07059 CMP #[CCS.COL1!CCS.9]+1 ;
AFDD 9008 07060 BCC SKIP144 ;
AFDF A940 07061 LDA #[CCS.COL1!CCS.0] ;
AFE1 9D5009 07062 STA KILLCNTD1,X ;
AFE4 CA 07063 DEX ;
AFE5 10EE 07064 BPL LOOP049 ;
07065
AFE7 206BAC 07066 SKIP144 JSR INITEXPL ; Init explosion at hit PLAYER
07067
07068 ;*** Any Zylon ships left? *****************************************************
AFEA A27F 07069 LDX #127 ; Scan all sectors of Galactic Chart
AFEC BDC908 07070 LOOP050 LDA GCMEMMAP,X ;
AFEF 3002 07071 BMI SKIP145 ;
AFF1 D00A 07072 BNE SKIP146 ; Return if Zylon sector found
AFF3 CA 07073 SKIP145 DEX ;
AFF4 10F6 07074 BPL LOOP050 ;
07075
07076 ;*** Game over (Mission Complete) **********************************************
AFF6 A03F 07077 LDY #$3F ; Set title phrase "MISSION COMPLETE"
AFF8 A200 07078 LDX #0 ; Set mission bonus offset
AFFA 2021B1 07079 JSR GAMEOVER2 ; Game over
AFFD 60 07080 SKIP146 RTS ; Return
07081
07082 ;*******************************************************************************
07083 ;* *
07084 ;* KEYBOARD *
07085 ;* *
07086 ;* Handle Keyboard Input *
07087 ;* *
07088 ;*******************************************************************************
07089
07090 ; DESCRIPTION
07091 ;
07092 ; If a keyboard code has been collected during a keyboard IRQ in the Immediate
07093 ; Interrupt Request handler IRQHNDLR ($A751), the idle counter is reset and the
07094 ; PLAYER-PLAYFIELD priority arranges the PLAYERs in front of the PLAYFIELD.
07095 ;
07096 ; Then, the keyboard code is compared with keyboard codes of table KEYTAB
07097 ; ($BABE). If no match is found the "WHAT'S WRONG" message is displayed in the
07098 ; title line and code execution returns.
07099 ;
07100 ; If one of the speed keys '0'..'9' has been pressed, a pending hyperwarp is
07101 ; aborted in subroutine ABORTWARP ($A980) and code execution returns. Otherwise
07102 ; the Engines drain rate is adjusted as well as the new velocity of our
07103 ; starship. If the Engines are damaged, a maximum speed is possible equivalent
07104 ; to speed key '5'.
07105 ;
07106 ; If one of our starship's view keys 'F' (Front), 'A' (Aft), 'G' (Galactic
07107 ; Chart), or 'L' (Long-Range Scan) have been pressed, the Display List is
07108 ; modified accordingly in subroutine MODDLST ($ADF1) and a new star field of 12
07109 ; stars is created with the help of subroutine INITPOSVEC ($B764). Code
07110 ; execution returns via subroutine UPDSCREEN ($B07B).
07111 ;
07112 ; If one of the 'T' (Tracking Computer), 'S' (Shields) or 'C' (Attack Computer)
07113 ; keys have been pressed, the corresponding status bits are toggled and the
07114 ; title line is updated with the corresponding title phrase. The beeper sound
07115 ; pattern ACKNOWLEDGE is played in subroutine BEEP ($B3A6). The tracking letter
07116 ; of the Control Panel Display is updated and the PLAYFIELD is cleared in
07117 ; subroutine CLRPLAYFIELD ($AE0D). If the Attack Computer is on, the Front or
07118 ; Aft view cross hairs are drawn, depending on the current view of our starship,
07119 ; via subroutine DRAWLINES ($A76F).
07120 ;
07121 ; If the 'H' (Hyperwarp) key has been pressed then the hyperwarp is engaged. Our
07122 ; starship's velocity is set to the maximum value, the Engines drain rate is
07123 ; increased to the equivalent of speed key '7'. Star trails are prepared. The
07124 ; position vector of the Hyperwarp Target Marker (PLAYER3) is set to the
07125 ; following values:
07126 ;
07127 ; x-coordinate := +0 (+$0000) <KM>
07128 ; y-coordinate := +256 (+$0100) <KM>
07129 ; z-coordinate := + (+$****) <KM> (sign only)
07130 ;
07131 ; The velocity vector is set to the following values:
07132 ;
07133 ; x-velocity := (not initialized)
07134 ; y-velocity := (not initialized)
07135 ; z-velocity := +0 <KM/H>
07136 ;
07137 ; The temporary arrival hyperwarp marker column and row numbers are saved. If we
07138 ; are not in a NOVICE mission, the maximum veer-off velocity of the Hyperwarp
07139 ; Target Marker during hyperwarp is picked from table VEERMASKTAB ($BED7). This
07140 ; value depends on the selected hyperwarp energy (and thus on the distance to
07141 ; hyperwarp). Finally, the title line displays the "HYPERWARP ENGAGED" message.
07142 ;
07143 ; If the 'M' (Manual target selector) key has been pressed, the tracked target
07144 ; space object is swapped and the corresponding digit of the Control Panel
07145 ; Display is toggled between 0 and 1.
07146 ;
07147 ; If the 'P' (Pause) key has been pressed, an endless loop waits until the
07148 ; joystick is pushed.
07149 ;
07150 ; BUG (at $B103): The endless loop branches back one instruction too far.
07151 ; Suggested fix: Branch to instruction LDA PORTA at $B0FE.
07152 ;
07153 ; If the 'INV' (Abort mission) key has been pressed, the mission is aborted by
07154 ; setting the mission bonus offset, then displaying the "MISSION ABORTED"
07155 ; message in the title line. Code execution continues into subroutine GAMEOVER
07156 ; ($B10A).
07157 ;
07158 ; NOTE: This subroutine has two additional entry points:
07159 ;
07160 ; (1) SETVIEW ($B045), which is used to enforce the Front view. It is entered
07161 ; from the game loop GAMELOOP ($A1F3) and subroutines INITSTART ($A15E) and
07162 ; DECENERGY ($B86F).
07163 ;
07164 ; (2) UPDSCREEN ($B07B), which draws the cross hairs and the Attack Computer
07165 ; Display, and then sets the tracking letter of the Control Panel Display.
07166 ; It is entered from subroutine DOCKING ($ACE6).
07167
=006A 07168 L.KEYCODE = $6A ; Saves pressed keyboard code
07169
AFFE A5CA 07170 KEYBOARD LDA KEYCODE ; Return if no keyboard code collected
B000 F03E 07171 BEQ SKIP150 ;
07172
B002 A214 07173 LDX #20 ; Prep keyboard code table loop index
B004 856A 07174 STA L.KEYCODE ; Save keyboard code
07175
B006 A900 07176 LDA #0 ; Reset idle counter
B008 8566 07177 STA IDLECNTHI ;
B00A 85CA 07178 STA KEYCODE ; Clear keyboard code
07179
B00C A911 07180 LDA #$11 ; GTIA: Enable PLAYER4, prio: PLs > PFs > BGR
B00E 8D1BD0 07181 STA PRIOR ; (PLAYERs in front of stars - and cross hairs)
07182
07183 ;*** Search keyboard code in lookup table **************************************
07184
B011 BDBEBA 07185 LOOP051 LDA KEYTAB,X ; Loop over all valid keyboard codes
B014 C56A 07186 CMP L.KEYCODE ;
B016 F008 07187 BEQ SKIP147 ; Branch if matching entry found
B018 CA 07188 DEX ;
B019 10F6 07189 BPL LOOP051 ; Next keyboard code
07190
B01B A010 07191 LDY #$10 ; No match found...
B01D 4C23B2 07192 JMP SETTITLE ; ...set title phrase "WHATS WRONG?" and return
07193
07194 ;*** Handle '0'..'9' keyboard keys (speed) *************************************
B020 E00A 07195 SKIP147 CPX #10 ; Skip section if keyboard code does not match
B022 B01D 07196 BCS SKIP151 ;
07197
B024 A5C0 07198 LDA WARPSTATE ; Skip if hyperwarp disengaged...
B026 F003 07199 BEQ SKIP148 ;
B028 4C80A9 07200 JMP ABORTWARP ; ...else abort hyperwarp
07201
B02B 2C9309 07202 SKIP148 BIT GCSTATENG ; Skip if Engines are OK or destroyed
B02E 5006 07203 BVC SKIP149 ;
B030 E006 07204 CPX #6 ; Allow max velocity equivalent to speed key '5'
B032 9002 07205 BCC SKIP149 ;
B034 A205 07206 LDX #5 ;
07207
B036 BDD3BA 07208 SKIP149 LDA DRAINRATETAB,X ; Set Engines energy drain rate
B039 8580 07209 STA DRAINENGINES ;
B03B BDB4BA 07210 LDA VELOCITYTAB,X ; Set new velocity
B03E 8571 07211 STA NEWVELOCITY ;
B040 60 07212 SKIP150 RTS ; Return
07213
07214 ;*** Handle 'F', 'A', 'L', 'G' keyboard keys (our starship's views) ************
B041 E00E 07215 SKIP151 CPX #14 ; Skip section if keyboard code does not match
B043 B01B 07216 BCS SKIP152 ;
07217
07218 ;*** Entry to force Front view after game init and failed missions *************
B045 BD18BE 07219 SETVIEW LDA VIEWMODETAB-10,X ; Store our starship's view type
B048 85D0 07220 STA SHIPVIEW ;
07221
B04A BC82BA 07222 LDY DLSTFRAGOFFTAB-10,X ; Get DL fragment offset (Front, Aft, LRS, GC)
B04D A202 07223 LDX #$02 ; Switch to corresponding view
B04F A908 07224 LDA #$08 ;
B051 20F1AD 07225 JSR MODDLST ;
07226
B054 A210 07227 LDX #NUMSPCOBJ.NORM-1 ; Create new star field of 12 stars
B056 2064B7 07228 LOOP052 JSR INITPOSVEC ;
B059 CA 07229 DEX ;
B05A E005 07230 CPX #NUMSPCOBJ.PL ;
B05C B0F8 07231 BCS LOOP052 ;
07232
B05E 901B 07233 BCC UPDSCREEN ; Return via updating screen (below)
07234
07235 ;*** Handle 'T', 'S', 'C' keyboard keys (Tracking, Shields, Attack Computer) ***
B060 E011 07236 SKIP152 CPX #17 ; Skip section if keyboard code does not match
B062 B035 07237 BCS SKIP156 ;
07238
B064 BC18BE 07239 LDY MSGOFFTAB-14,X ; Prep title phrase offset "... OFF"
B067 B56E 07240 LDA ISTRACKCOMPON-14,X ; Toggle status bits (also energy consumption values)
B069 5D1BBE 07241 EOR MSGBITTAB-14,X ;
B06C 956E 07242 STA ISTRACKCOMPON-14,X ;
B06E F003 07243 BEQ SKIP153 ;
B070 BC1EBE 07244 LDY MSGONTAB-14,X ; Prep title phrase offset "... ON"
B073 2023B2 07245 SKIP153 JSR SETTITLE ; Set title phrase to "... ON" or "... OFF" version
07246
B076 A20C 07247 LDX #$0C ; Play beeper sound pattern ACKNOWLEDGE
B078 20A6B3 07248 JSR BEEP ;
07249
07250 ;*** Update PLAYFIELD (Cross hairs, Attack Computer, set tracking letter) ******
B07B A216 07251 UPDSCREEN LDX #CCS.T ; Get custom char 'T' (entry point TRANSFER COMPLETE)
B07D A47C 07252 LDY ISTRACKCOMPON ;
B07F F001 07253 BEQ SKIP154 ; Skip if Tracking Computer is on
07254
B081 E8 07255 INX ; Get custom char 'C'
07256
B082 8E5A09 07257 SKIP154 STX TRACKC1 ; Store tracking character in Control Panel Display
B085 200DAE 07258 JSR CLRPLAYFIELD ; Clear PLAYFIELD
B088 A57E 07259 LDA DRAINATTCOMP ; Return if Attack Computer off
B08A F0B4 07260 BEQ SKIP150 ;
07261
B08C A6D0 07262 LDX SHIPVIEW ; If Aft view -> Draw Aft cross hairs and return
B08E F006 07263 BEQ SKIP155 ; If Front view -> Draw Front cross hairs and ...
B090 E001 07264 CPX #$01 ; ...Attack Computer and return
B092 D0AC 07265 BNE SKIP150 ;
B094 A22A 07266 LDX #$2A ;
B096 4C6FA7 07267 SKIP155 JMP DRAWLINES ;
07268
07269 ;*** Handle 'H' keyboard key (Hyperwarp) ***************************************
B099 E011 07270 SKIP156 CPX #17 ; Skip if keyboard code does not match
B09B D050 07271 BNE SKIP158 ;
07272
07273 ;*** Engage Hyperwarp **********************************************************
B09D A5C0 07274 LDA WARPSTATE ; Return if hyperwarp engaged
B09F D05A 07275 BNE SKIP159 ;
07276
B0A1 A97F 07277 LDA #$7F ; Engage hyperwarp
B0A3 85C0 07278 STA WARPSTATE ;
B0A5 A9FF 07279 LDA #255 ; Set new velocity
B0A7 8571 07280 STA NEWVELOCITY ;
B0A9 A91E 07281 LDA #30 ; Set Engines energy drain rate (= speed key '7')
B0AB 8580 07282 STA DRAINENGINES ;
07283
B0AD A930 07284 LDA #NUMSPCOBJ.ALL-1 ; Set space obj index of first star of star trail
B0AF 85C3 07285 STA TRAILIND ;
B0B1 A900 07286 LDA #0 ; Clear star trail delay
B0B3 85C2 07287 STA TRAILDELAY ;
07288
B0B5 8D740A 07289 STA PL3XPOSHI ; Init position vector and velocity vector of...
B0B8 8D070B 07290 STA PL3XPOSLO ; ... Hyperwarp Target Marker (PLAYER3):
B0BB 8D380B 07291 STA PL3YPOSLO ; x-coordinate := +0 (+$0000) <KM>
B0BE 8D690B 07292 STA PL3ZVEL ; y-coordinate := +256 (+$0100) <KM>
B0C1 A901 07293 LDA #1 ; z-coordinate := + (+$****) <KM> (sign only)
B0C3 8DB009 07294 STA PL3ZPOSSIGN ; z-velocity := +0 <KM/H>
B0C6 8DE109 07295 STA PL3XPOSSIGN ;
B0C9 8D120A 07296 STA PL3YPOSSIGN ;
B0CC 8DA50A 07297 STA PL3YPOSHI ;
07298
B0CF A58F 07299 LDA WARPARRVCOLUMN ; Store temp arrival hyperwarp marker column number
B0D1 85C4 07300 STA WARPTEMPCOLUMN ;
B0D3 A58E 07301 LDA WARPARRVROW ; Store temp arrival hyperwarp marker row number
B0D5 85C5 07302 STA WARPTEMPROW ;
07303
B0D7 A562 07304 LDA MISSIONLEVEL ; Skip if NOVICE mission
B0D9 F00B 07305 BEQ SKIP157 ;
07306
B0DB A591 07307 LDA WARPENERGY ; Bits B0..1 of hyperwarp energy index a table...
B0DD 2A 07308 ROL A ; ...containing the maximum value of how much the...
B0DE 2A 07309 ROL A ; ...Hyperwarp Target Marker will veer off during...
B0DF 2A 07310 ROL A ; ...hyperwarp
B0E0 2903 07311 AND #$03 ;
B0E2 A8 07312 TAY ;
B0E3 B9D7BE 07313 LDA VEERMASKTAB,Y ;
07314
B0E6 85C6 07315 SKIP157 STA VEERMASK ; Store veer-off velocity limitation mask
07316
B0E8 A011 07317 LDY #$11 ; Set title phrase "HYPERWARP ENGAGED" and return
B0EA 4C23B2 07318 JMP SETTITLE ;
07319
07320 ;*** Handle 'M' keyboard key (Manual Target Selector) key **********************
B0ED E013 07321 SKIP158 CPX #19 ; Skip if keyboard code does not match
B0EF B00B 07322 BCS SKIP160 ;
07323
B0F1 AD5C09 07324 LDA TRACKDIGIT ; Toggle digit of tracked space object of...
B0F4 4901 07325 EOR #$01 ; ... Control Panel Display
B0F6 2901 07326 AND #$01 ;
B0F8 8D5C09 07327 STA TRACKDIGIT ;
B0FB 60 07328 SKIP159 RTS ; Return
07329
07330 ;*** Handle 'P' keyboard key (Pause) *******************************************
B0FC D008 07331 SKIP160 BNE SKIP161 ; Skip if keyboard code does not match
07332
B0FE AD00D3 07333 LDA PORTA ; Push joystick to resume action
B101 C9FF 07334 CMP #$FF ;
B103 F0F7 07335 BEQ SKIP160 ; (!)
B105 60 07336 RTS ; Return
07337
07338 ;*** Handle 'INV' keyboard key (Abort Mission) *********************************
B106 A076 07339 SKIP161 LDY #$76 ; Preload title phrase "MISSION ABORTED..."
B108 A204 07340 LDX #$04 ; Set mission bonus offset
07341
07342 ;*******************************************************************************
07343 ;* *
07344 ;* GAMEOVER *
07345 ;* *
07346 ;* Handle game over *
07347 ;* *
07348 ;*******************************************************************************
07349
07350 ; DESCRIPTION
07351 ;
07352 ; Handles game over, including calculating the scored rank and class.
07353 ;
07354 ; This subroutine has two entry points:
07355 ;
07356 ; (1) GAMEOVER ($B10A) is entered at the end of a failed mission (mission
07357 ; aborted, zero energy, or starship destroyed by Zylon fire), essentially
07358 ; shutting down our starship. Code execution continues into GAMEOVER2
07359 ; ($B121) below.
07360 ;
07361 ; (2) GAMEOVER2 ($B121) is entered at the end of a successful mission (all
07362 ; Zylon ships destroyed). It puts the game in demo mode, enqueues the
07363 ; corresponding game over message, and calculates the scored rank and
07364 ; class.
07365 ;
07366 ; The scored rank and class are based on the total score. This is the score
07367 ; accumulated during the game plus a mission bonus, which depends on the
07368 ; mission level and on how the mission ended (mission complete, mission
07369 ; aborted, or starship destroyed by Zylon fire). The mission bonus is
07370 ; picked from table BONUSTAB ($BEDD).
07371 ;
07372 ; The scored rank index is taken from bits B8..4 of the total score and
07373 ; limited to values of 0..18. It indexes table RANKTAB ($BEE9) for the rank
07374 ; string. The rank string is displayed in subroutine SETTITLE ($B223).
07375 ;
07376 ; The scored class index is taken from bits B3..0 (for rank indices 0,
07377 ; 11..14) and computed from bits B4..1 (for rank indices 1..10 and 15..18).
07378 ; It takes values of 0..15. It indexes table CLASSTAB ($BEFC) for the class
07379 ; digit. The class digit is displayed in subroutine SETTITLE ($B223).
07380 ;
07381 ; For quick lookup, the following table lists rank and class from the total
07382 ; score. Use the table as follows: Pick the cell with the closest value
07383 ; less or equal to your score then read the rank and class off the left and
07384 ; the top of the table, respectively.
07385 ;
07386 ; For example: A score of 90 results in a ranking of "Novice Class 4", a
07387 ; score of 161 results in a ranking of "Pilot Class 3".
07388 ;
07389 ; +------------------------------+---------------------------------------------------------------+
07390 ; | Minimum Total Score | Class Index |
07391 ; | | 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15|
07392 ; +-------+----------------------+---------------------------------------------------------------+
07393 ; | Rank | | Class |
07394 ; | Index | Rank | 5 5 5 4 4 4 4 3 3 3 2 2 2 1 1 1|
07395 ; +-------+----------------------+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
07396 ; | 0 | Galactic Cook | 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 10| 11| 12| 13| 14| 15|
07397 ; | 1 | Garbage Scow Captain | 16| 18| 20| 22| 24| 26| 28| 30| | | | | | | | |
07398 ; | 2 | Garbage Scow Captain | | | | | | | | | 32| 34| 36| 38| 40| 42| 44| 46|
07399 ; | 3 | Rookie | 48| 50| 52| 54| 56| 58| 60| 62| | | | | | | | |
07400 ; | 4 | Rookie | | | | | | | | | 64| 66| 68| 70| 72| 74| 76| 78|
07401 ; | 5 | Novice | 80| 82| 84| 86| 88| 90| 92| 94| | | | | | | | |
07402 ; | 6 | Novice | | | | | | | | | 96| 98|100|102|104|106|108|110|
07403 ; | 7 | Ensign |112|114|116|118|120|122|124|126| | | | | | | | |
07404 ; | 8 | Ensign | | | | | | | | |128|130|132|134|136|138|140|142|
07405 ; | 9 | Pilot |144|146|148|150|152|154|156|158| | | | | | | | |
07406 ; | 10 | Pilot | | | | | | | | |160|162|164|166|168|170|172|174|
07407 ; | 11 | Ace |176|177|178|179|180|181|182|183|184|185|186|187|188|189|190|191|
07408 ; | 12 | Lieutenant |192|193|194|195|196|197|198|199|200|201|202|203|204|205|206|207|
07409 ; | 13 | Warrior |208|209|210|211|212|213|214|215|216|217|218|219|220|221|222|223|
07410 ; | 14 | Captain |224|225|226|227|228|229|230|231|232|233|234|235|236|237|238|239|
07411 ; | 15 | Commander |240|242|244|246|248|250|252|254| | | | | | | | |
07412 ; | 16 | Commander | | | | | | | | |256|258|260|262|264|266|268|270|
07413 ; | 17 | Star Commander |272|274|276|278|280|282|284|286| | | | | | | | |
07414 ; | 18 | Star Commander | | | | | | | | |288|290|292|294|296|298|300|302|
07415 ; +-------+----------------------+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
07416 ;
07417 ; NOTE: This subroutine also clears the vertical and horizontal joystick
07418 ; directions.
07419 ;
07420 ; INPUT
07421 ;
07422 ; X = Offset to index table BONUSTAB ($BEDD) of mission bonus values. Used
07423 ; values are:
07424 ; $00 -> Mission complete
07425 ; $04 -> Mission was aborted due to zero energy
07426 ; $08 -> Our starship was destroyed by Zylon fire
07427 ;
07428 ; Y = Title phrase offset. Used values are:
07429 ; $3F -> "MISSION COMPLETE"
07430 ; $31 -> "MISSION ABORTED ZERO ENERGY"
07431 ; $23 -> "SHIP DESTROYED BY ZYLON FIRE"
07432
07433 ;*** Game over (Mission failed) ************************************************
B10A A900 07434 GAMEOVER LDA #0 ;
B10C 85EC 07435 STA PL3LIFE ; PLAYER3 lifetime := 0 game loops
B10E 85D6 07436 STA BEEPPRIORITY ; Mute beeper
B110 85D1 07437 STA TITLEPHR ; Clear title line
B112 858B 07438 STA REDALERTLIFE ; Red alert flash lifetime := 0 game loops
B114 8D07D2 07439 STA AUDC4 ; Mute audio channel 4
B117 8571 07440 STA NEWVELOCITY ; Shut down Engines
B119 8581 07441 STA SHIELDSCOLOR ; Set Shields color to {BLACK}
B11B 857D 07442 STA DRAINSHIELDS ; Switch off Shields
B11D 85C0 07443 STA WARPSTATE ; Disengage hyperwarp
B11F 85C1 07444 STA VELOCITYHI ; Turn off hyperwarp velocity
07445
07446 ;*** Game over (Mission successful) ********************************************
B121 A9FF 07447 GAMEOVER2 LDA #$FF ; Enter demo mode
B123 8564 07448 STA ISDEMOMODE ;
07449
B125 8465 07450 STY NEWTITLEPHR ; Enqueue title phrase
07451
07452 ;*** Calculate total score *****************************************************
B127 8A 07453 TXA ;
B128 0562 07454 ORA MISSIONLEVEL ;
B12A AA 07455 TAX ;
B12B BDDDBE 07456 LDA BONUSTAB,X ; Retrieve mission bonus
B12E 18 07457 CLC ; Add mission bonus and game score
B12F 65CB 07458 ADC SCORE ;
B131 AA 07459 TAX ;
B132 A900 07460 LDA #0 ;
07461
B134 85C9 07462 STA JOYSTICKY ; Clear vertical joystick delta
B136 85C8 07463 STA JOYSTICKX ; Clear horizontal joystick delta
07464
B138 65CC 07465 ADC SCORE+1 ;
B13A 3025 07466 BMI SKIP165 ; Return if total score < 0 (= total score of 0)
07467
07468 ;*** Calculate scored rank *****************************************************
B13C 4A 07469 LSR A ;
B13D 8A 07470 TXA ;
B13E 6A 07471 ROR A ;
B13F 4A 07472 LSR A ;
B140 4A 07473 LSR A ;
B141 4A 07474 LSR A ; Use bits B8..4 of total score as rank index
B142 C913 07475 CMP #19 ; Limit scored rank index to 0..18
B144 9004 07476 BCC SKIP162 ;
B146 A912 07477 LDA #18 ;
B148 A20F 07478 LDX #15 ; Prep class index of 15
B14A 85CD 07479 SKIP162 STA SCOREDRANKIND ; Store scored rank index
07480
07481 ;*** Calculate scored class ****************************************************
B14C A8 07482 TAY ;
B14D 8A 07483 TXA ;
B14E C000 07484 CPY #0 ;
B150 F00B 07485 BEQ SKIP164 ;
B152 C00B 07486 CPY #11 ;
B154 9004 07487 BCC SKIP163 ;
B156 C00F 07488 CPY #15 ;
B158 9003 07489 BCC SKIP164 ;
B15A 4A 07490 SKIP163 LSR A ;
B15B 4908 07491 EOR #$08 ;
B15D 290F 07492 SKIP164 AND #$0F ;
B15F 85CE 07493 STA SCOREDCLASSIND ; Store scored class index, is 0..15
07494
B161 60 07495 SKIP165 RTS ; Return
07496
07497 ;*******************************************************************************
07498 ;* *
07499 ;* SELECTWARP *
07500 ;* *
07501 ;* Select hyperwarp arrival location on Galactic Chart *
07502 ;* *
07503 ;*******************************************************************************
07504
07505 ; DESCRIPTION
07506 ;
07507 ; This subroutine executes the following steps:
07508 ;
07509 ; (1) Check if we are in Galactic Chart view and not in hyperwarp.
07510 ;
07511 ; (2) Update the Galactic Chart in subroutine DRAWGC ($B4B9) if the Subspace
07512 ; Radio is not damaged.
07513 ;
07514 ; (3) Move the arrival hyperwarp marker (PLAYER4) across the Galactic Chart
07515 ; every other game loop iteration. The current location of our starship is
07516 ; indicated by the departure hyperwarp marker (PLAYER3).
07517 ;
07518 ; Code execution continues into subroutine CALCWARP ($B1A7) to calculate the
07519 ; required hyperwarp energy to hyperwarp from the departure hyperwarp marker
07520 ; position to the arrival hyperwarp marker position.
07521 ;
07522 ; NOTE: To calculate the horizontal position of PLAYER3..4 an offset of 61 is
07523 ; added (from left to right: 48 Player/Missile (PM) pixels to the left edge of
07524 ; the screen + 16 PM pixels to the left border of the Galactic Chart - 3 PM
07525 ; pixels relative offset of the PLAYER shape's horizontal center to its left
07526 ; edge = 61 PM pixels).
07527 ;
07528 ; NOTE: To calculate the vertical position of PLAYER3..4 an offset of 63 is
07529 ; added (from top to bottom: 8 Player/Missile (PM) pixels to the start of the
07530 ; Display List + 56 PM pixels to the first row of sectors - 1 PM pixel relative
07531 ; offset of the PLAYER shape's vertical center to its top edge (?) = 63 PM
07532 ; pixels).
07533
B162 A5C0 07534 SELECTWARP LDA WARPSTATE ; Return if hyperwarp engaged
B164 D004 07535 BNE SKIP166 ;
07536
B166 A5D0 07537 LDA SHIPVIEW ; Return if not in Galactic Chart view
B168 3001 07538 BMI SKIP167 ;
B16A 60 07539 SKIP166 RTS ; Return
07540
B16B 2C9709 07541 SKIP167 BIT GCSTATRAD ; Skip if Subspace Radio is damaged or destroyed
B16E 3003 07542 BMI SKIP168 ;
07543
B170 20B9B4 07544 JSR DRAWGC ; Redraw Galactic Chart
07545
B173 A572 07546 SKIP168 LDA COUNT8 ; Move hyperwarp markers only every other game loop
B175 2901 07547 AND #$01 ; (slowing down movement of hyperwarp markers)
B177 D02E 07548 BNE CALCWARP ;
07549
07550 ;*** Calc arrival hyperwarp marker column and row numbers, update PLAYER4 pos **
B179 18 07551 CLC ;
B17A A58F 07552 LDA WARPARRVCOLUMN ; Load arrival hyperwarp marker column number
B17C 65C8 07553 ADC JOYSTICKX ; Add joystick x-delta
B17E 297F 07554 AND #$7F ; Limit value to 0..127
B180 858F 07555 STA WARPARRVCOLUMN ; Save new arrival hyperwarp marker column number
B182 18 07556 CLC ;
B183 693D 07557 ADC #61 ; Add offset of 61
B185 8D2E0C 07558 STA PL4COLUMN ; Store as PLAYER4 column number
07559
B188 18 07560 CLC ;
B189 A58E 07561 LDA WARPARRVROW ; Load arrival hyperwarp marker row number
B18B 65C9 07562 ADC JOYSTICKY ; Add joystick y-delta
B18D 297F 07563 AND #$7F ; Limit value to 0..127
B18F 858E 07564 STA WARPARRVROW ; Save new arrival hyperwarp marker row number
B191 18 07565 CLC ;
B192 693F 07566 ADC #63 ; Add offset of 63
B194 8DFD0B 07567 STA PL4ROWNEW ; Store as PLAYER4 row number
07568
07569 ;*** Calc departure hyperwarp marker column and row numbers, update PLAYER3 pos
B197 A58C 07570 LDA WARPDEPRROW ; Load departure hyperwarp marker row number
B199 18 07571 CLC ;
B19A 693F 07572 ADC #63 ; Add offset of 63
B19C 8DFC0B 07573 STA PL3ROWNEW ; Store as PLAYER3 row number
07574
B19F A58D 07575 LDA WARPDEPRCOLUMN ; Load departure hyperwarp marker column number
B1A1 18 07576 CLC ;
B1A2 693D 07577 ADC #61 ; Add offset of 61
B1A4 8D2D0C 07578 STA PL3COLUMN ; Store as PLAYER3 column number
07579
07580 ;*******************************************************************************
07581 ;* *
07582 ;* CALCWARP *
07583 ;* *
07584 ;* Calculate and display hyperwarp energy *
07585 ;* *
07586 ;*******************************************************************************
07587
07588 ; DESCRIPTION
07589 ;
07590 ; Calculates and displays the hyperwarp energy in the Galactic Chart view.
07591 ;
07592 ; This subroutine executes the following steps:
07593 ;
07594 ; (1) Determine the arrival sector from the arrival hyperwarp marker position.
07595 ;
07596 ; (2) If the Subspace Radio is not destroyed, update the target number digit of
07597 ; the Galactic Chart Panel Display.
07598 ;
07599 ; (3) Calculate the hyperwarp energy that is required to hyperwarp from the
07600 ; departure hyperwarp marker to the arrival hyperwarp marker based on the
07601 ; "block-distance":
07602 ;
07603 ; DISTANCE := DELTAR / 2 + DELTAC
07604 ;
07605 ; where
07606 ;
07607 ; DELTAR := ABS(WARPARRVROW - WARPDEPRROW)
07608 ; DELTAC := ABS(WARPARRVCOLUMN - WARPDEPRCOLUMN)
07609 ;
07610 ; NOTE: Dividing DELTAR by 2 compensates for PLAYERs at single-line
07611 ; resolution having Player/Missile pixels that are half as high as they are
07612 ; wide.
07613 ;
07614 ; The hyperwarp energy, divided by 10, is the sum of a value picked from
07615 ; the hyperwarp energy table WARPENERGYTAB ($BADD) indexed by DISTANCE / 8)
07616 ; plus a remainder computed from Bits B1..0 of DISTANCE.
07617 ;
07618 ; (4) Store the hyperwarp energy value in WARPENERGY ($91).
07619 ;
07620 ; (5) Update the HYPERWARP ENERGY readout of the Galactic Chart Panel Display.
07621
=006A 07622 L.WARPARRVCOL = $6A ; Saves arrival sector column number
=006A 07623 L.DELTAC = $6A ; Saves diff column value
07624
07625 ;*** Calculate arrival sector **************************************************
B1A7 A58F 07626 CALCWARP LDA WARPARRVCOLUMN ;
B1A9 4A 07627 LSR A ;
B1AA 4A 07628 LSR A ;
B1AB 4A 07629 LSR A ;
B1AC 856A 07630 STA L.WARPARRVCOL ; A := arrival sector column 0..15
B1AE A58E 07631 LDA WARPARRVROW ;
B1B0 2970 07632 AND #$70 ; A := arrival sector row (0..7) * 16
B1B2 056A 07633 ORA L.WARPARRVCOL ;
B1B4 8592 07634 STA ARRVSECTOR ; Save arrival sector (format %0rrrcccc)
07635
07636 ;*** Update target number digit of Galactic Chart Panel Display ****************
B1B6 AA 07637 TAX ;
B1B7 BDC908 07638 LDA GCMEMMAP,X ; Get number of Zylon ships in arrival sector
B1BA 1002 07639 BPL SKIP169 ; Skip if no starbase in arrival sector
B1BC A900 07640 LDA #0 ; Clear number of Zylon ships
B1BE 0990 07641 SKIP169 ORA #CCS.COL2!ROM.0 ; Merge COLOR2 bits with number of Zylon ships
B1C0 2C9709 07642 BIT GCSTATRAD ; Skip if Subspace Radio destroyed
B1C3 7003 07643 BVS SKIP170 ;
07644
B1C5 8D8D09 07645 STA GCTRGCNT ; Set target number digit of Galactic Chart Panel
07646
07647 ;*** Calculate energy to hyperwarp between hyperwarp markers *******************
B1C8 38 07648 SKIP170 SEC ; A := DELTAC := ABS(WARPARRVCOLUMN - WARPDEPRCOLUMN)
B1C9 A58F 07649 LDA WARPARRVCOLUMN ; (Column value difference)
B1CB E58D 07650 SBC WARPDEPRCOLUMN ;
B1CD B004 07651 BCS SKIP171 ;
B1CF 49FF 07652 EOR #$FF ;
B1D1 6901 07653 ADC #1 ;
B1D3 856A 07654 SKIP171 STA L.DELTAC ;
07655
B1D5 38 07656 SEC ; A := DELTAR := ABS(WARPARRVROW - WARPDEPRROW)
B1D6 A58E 07657 LDA WARPARRVROW ; (Row value difference)
B1D8 E58C 07658 SBC WARPDEPRROW ;
B1DA B004 07659 BCS SKIP172 ;
B1DC 49FF 07660 EOR #$FF ;
B1DE 6901 07661 ADC #1 ;
07662
B1E0 4A 07663 SKIP172 LSR A ; A := DISTANCE := DELTAR / 2 + DELTAC
B1E1 18 07664 CLC ;
B1E2 656A 07665 ADC L.DELTAC ;
07666
B1E4 A8 07667 TAY ; Save DISTANCE
B1E5 4A 07668 LSR A ; Calc index into hyperwarp energy table
B1E6 4A 07669 LSR A ;
B1E7 4A 07670 LSR A ;
B1E8 AA 07671 TAX ;
07672
B1E9 98 07673 TYA ; Load DISTANCE value
B1EA 2903 07674 AND #$03 ; Get DISTANCE bits B1..0
B1EC 18 07675 CLC ;
B1ED 7DDDBA 07676 ADC WARPENERGYTAB,X ; Add hyperwarp energy from table
B1F0 8591 07677 STA WARPENERGY ; Save hyperwarp energy
07678
07679 ;*** Update HYPERWARP ENERGY readout of Galactic Chart Panel Display ***********
B1F2 A8 07680 TAY ; Prep with hyperwarp energy value
07681
B1F3 A910 07682 LDA #ROM.0 ; Set HYPERWARP ENERGY readout digit1..3 to '0'
B1F5 8D7D09 07683 STA GCWARPD1 ;
B1F8 8D7E09 07684 STA GCWARPD1+1 ;
B1FB 8D7F09 07685 STA GCWARPD1+2 ;
07686
B1FE A202 07687 LOOP053 LDX #2 ; Loop over HYPERWARP ENERGY readout digit3..1
B200 FE7D09 07688 LOOP054 INC GCWARPD1,X ; Increment digit value
B203 BD7D09 07689 LDA GCWARPD1,X ;
B206 C91A 07690 CMP #ROM.9+1 ;
B208 9008 07691 BCC SKIP173 ; Skip if energy digit <= '9'
07692
B20A A910 07693 LDA #ROM.0 ; Replace energy digit with '0'
B20C 9D7D09 07694 STA GCWARPD1,X ;
B20F CA 07695 DEX ;
B210 10EE 07696 BPL LOOP054 ; Next energy digit
07697
B212 88 07698 SKIP173 DEY ; Decrement HYPERWARP ENERGY readout value
B213 D0E9 07699 BNE LOOP053 ;
B215 60 07700 RTS ; Return
07701
07702 ;*******************************************************************************
07703 ;* *
07704 ;* UPDTITLE *
07705 ;* *
07706 ;* Update title line *
07707 ;* *
07708 ;*******************************************************************************
07709
07710 ; DESCRIPTION
07711 ;
07712 ; Updates the title phrase displayed in the title line.
07713 ;
07714 ; If no title phrase has been set then fetch the offset of the next ("enqueued")
07715 ; title phrase to be displayed. If one has been set then code execution
07716 ; continues into subroutine SETTITLE ($B223), otherwise code execution returns.
07717 ;
07718 ; If a title phrase has been set then decrement the lifetime of the currently
07719 ; displayed title phrase segment. If its lifetime has reached a value of 0 then
07720 ; branch to subroutine SETTITLE ($B223) to display the next segment.
07721
B216 A5D1 07722 UPDTITLE LDA TITLEPHR ; Skip if no title phrase set
B218 F005 07723 BEQ SKIP175 ;
07724
B21A C6CF 07725 DEC TITLELIFE ; Decrement title phrase segment lifetime
B21C F010 07726 BEQ SKIP176 ; If lifetime expired show next title segment
07727
B21E 60 07728 SKIP174 RTS ; Return
07729
B21F A465 07730 SKIP175 LDY NEWTITLEPHR ; Prep enqueued new title phrase
B221 F0FB 07731 BEQ SKIP174 ; Return if not set
07732
07733 ;*******************************************************************************
07734 ;* *
07735 ;* SETTITLE *
07736 ;* *
07737 ;* Set title phrase in title line *
07738 ;* *
07739 ;*******************************************************************************
07740
07741 ; DESCRIPTION
07742 ;
07743 ; Displays a title phrase in the title line.
07744 ;
07745 ; INTRODUCTION
07746 ;
07747 ; Title phrases are picked from the title phrase table PHRASETAB ($BBAA). They
07748 ; consist of one or more phrase tokens. Each token is a byte representing a word
07749 ; in word table WORDTAB ($BC2B). Two special tokens are placeholders for the
07750 ; scored class string ($FC) and scored rank string ($FD).
07751 ;
07752 ; A title phrase is split up into one or more title phrase segments, each
07753 ; fitting into the title line. One title phrase segment is displayed after the
07754 ; other after a delay called the "title segment lifetime".
07755 ;
07756 ; Phrase tokens, except the tokens for the scored class ($FC) and for the scored
07757 ; rank ($FD), contain the number of a word in word table WORDTAB ($BC2B) and may
07758 ; contain an end-of-segment or end-of-phrase marker bit.
07759 ;
07760 ; DETAILS
07761 ;
07762 ; The Display List is modified by subroutine MODDLST ($ADF1) to display the
07763 ; title line. Then, the title line is cleared and the words of the title phrase
07764 ; are copied into it using the passed offset into title phrase table PHRASETAB
07765 ; ($BBAA). If the offset has a value of $FF the title line is hidden in
07766 ; subroutine MODDLST ($ADF1).
07767 ;
07768 ; INPUT
07769 ;
07770 ; Y = Offset into title phrase table PHRASETAB ($BBAA). Used values are:
07771 ; $FF -> Hide title line
07772 ; else -> Offset into title phrase table PHRASETAB ($BBAA), with explicitly
07773 ; used values:
07774 ;
07775 ; $01 -> "COMPUTER ON"
07776 ; $04 -> "COMPUTER OFF"
07777 ; $07 -> "SHIELDS ON"
07778 ; $09 -> "SHIELDS OFF"
07779 ; $0B -> "COMPUTER TRACKING ON"
07780 ; $0E -> "TRACKING OFF"
07781 ; $13 -> "STARBASE SURROUNDED"
07782 ; $15 -> "STARBASE DESTROYED"
07783 ; $1F -> "DOCKING ABORTED"
07784 ; $21 -> "TRANSFER COMPLETE"
07785 ; $4A -> "NOVICE MISSION"
07786 ; $4C -> "PILOT MISSION"
07787 ; $4E -> "WARRIOR MISSION"
07788 ; $50 -> "COMMANDER MISSION"
07789 ; $52 -> "DAMAGE CONTROL..."
07790 ; $75 -> "RED ALERT"
07791
=006A 07792 L.WORD = $6A ; Saves word number of WORDTAB ($BC2A). Used values
07793 ; are $00..$3F.
=006B 07794 L.COLUMNPOS = $6B ; Saves cursor column position during copying text
07795 ; into title line
=006C 07796 L.TOKEN = $6C ; Saves title phrase token from PHRASETAB ($BBAA),
07797 ; contains bit-encoded information about one word in
07798 ; the title phrase:
07799 ; B7..6 = %00 -> Copy next word to title line
07800 ; B7..6 = %01 -> End-of-phrase reached, apply short
07801 ; delay, then hide title line. Title
07802 ; segment lifetime = 60 game loops.
07803 ; B7..6 = %10 -> End-of-segment reached. Title
07804 ; segment lifetime = 60 game loops
07805 ; B7..6 = %11 -> End-of-phrase reached, apply long
07806 ; delay, then hide title line. Title
07807 ; segment lifetime = 254 game loops.
07808 ; Used with title phrases
07809 ; "STARBASE SURROUNDED"
07810 ; "STARBASE DESTROYED"
07811 ; "HYPERSPACE"
07812 ; "RED ALERT"
07813 ; B5..0 -> Word number of WORDTAB ($BC2A)
07814
B223 84D1 07815 SETTITLE STY TITLEPHR ; Save title phrase offset
07816
B225 A023 07817 LDY #$23 ; Show title line
B227 A20F 07818 LDX #$0F ;
B229 A907 07819 LDA #$07 ;
B22B 20F1AD 07820 JSR MODDLST ;
07821
07822 ;*** Init cursor column position and clear title line **************************
B22E A213 07823 SKIP176 LDX #19 ; There are 19(+1) characters to clear
B230 A900 07824 LDA #0 ;
B232 856B 07825 STA L.COLUMNPOS ; Init cursor column position
07826
B234 9D1F0D 07827 LOOP055 STA TITLETXT,X ; Clear character in title line
B237 CA 07828 DEX ;
B238 10FA 07829 BPL LOOP055 ;
07830
07831 ;*** If title phrase offset = $FF then hide title line *************************
B23A A6D1 07832 SKIP177 LDX TITLEPHR ; Load title phrase offset
B23C E6D1 07833 INC TITLEPHR ; Prepare title phrase offset for next word
B23E D009 07834 BNE SKIP178 ; ...skip if it turned 0
07835
B240 A20F 07836 LDX #$0F ; Remove title line and return
B242 A080 07837 LDY #$80 ;
B244 A907 07838 LDA #$07 ;
B246 4CF1AD 07839 JMP MODDLST ;
07840
B249 BDAABB 07841 SKIP178 LDA PHRASETAB,X ; Get phrase token
07842
07843 ;*** Display scored class? *****************************************************
B24C C9FC 07844 CMP #$FC ; Skip if not "scored class" token
B24E D00F 07845 BNE SKIP179 ;
07846
B250 A4CE 07847 LDY SCOREDCLASSIND ; Get scored class index, is in 0..15
B252 B9FCBE 07848 LDA CLASSTAB,Y ; Load scored class number digit
B255 A66B 07849 LDX L.COLUMNPOS ; Load cursor position
B257 9D1F0D 07850 STA TITLETXT,X ; Store class in title line
B25A A93C 07851 LDA #60 ; Title segment lifetime := 60 game loops
B25C 85CF 07852 STA TITLELIFE ;
B25E 60 07853 RTS ; Return
07854
07855 ;*** Display scored rank? ******************************************************
B25F C9FD 07856 SKIP179 CMP #$FD ; Skip if not "scored rank" token
B261 D005 07857 BNE SKIP180 ;
07858
B263 A4CD 07859 LDY SCOREDRANKIND ; Get scored rank index, is in 0..18
B265 B9E9BE 07860 LDA RANKTAB,Y ; Load rank word number
07861
07862 ;*** Search word of token in word table ****************************************
B268 856C 07863 SKIP180 STA L.TOKEN ; Save phrase token
B26A 293F 07864 AND #$3F ; Strip bits B6..7 from phrase token
B26C 856A 07865 STA L.WORD ; Store word number (bits B5..0)
07866
B26E A92A 07867 LDA #<[WORDTAB-1] ; Point MEMPTR to WORDTAB-1
B270 8568 07868 STA MEMPTR ;
B272 A9BC 07869 LDA #>[WORDTAB-1] ;
B274 8569 07870 STA MEMPTR+1 ;
07871
B276 E668 07872 LOOP056 INC MEMPTR ; Increment MEMPTR
B278 D002 07873 BNE SKIP181 ;
B27A E669 07874 INC MEMPTR+1 ;
07875
B27C A000 07876 SKIP181 LDY #0 ;
B27E B168 07877 LDA (MEMPTR),Y ; Load character of word
B280 10F4 07878 BPL LOOP056 ; Loop until end-of-word marker (bit B7) found
B282 C66A 07879 DEC L.WORD ;
B284 D0F0 07880 BNE LOOP056 ; Loop until word found
07881
07882 ;*** Copy word to title line, add space ****************************************
B286 293F 07883 LOOP057 AND #$3F ; Strip color bits B6..7 from character
B288 49A0 07884 EOR #CCS.COL2!$20 ; Merge COLOR2 bits and convert to ATASCII
B28A A66B 07885 LDX L.COLUMNPOS ; Copy character to title line
B28C E66B 07886 INC L.COLUMNPOS ; Increment cursor column position
B28E 9D1F0D 07887 STA TITLETXT,X ;
B291 C8 07888 INY ;
B292 B168 07889 LDA (MEMPTR),Y ; Load next character of word
B294 10F0 07890 BPL LOOP057 ; Next character of word if no end-of-word marker
B296 E66B 07891 INC L.COLUMNPOS ; Word was copied. Add space after word.
07892
07893 ;*** Decide to copy another word, etc. *****************************************
B298 A93C 07894 LDA #60 ; SUMMARY:
B29A 246C 07895 BIT L.TOKEN ; If bits B7..6 of phrase token...
B29C 1004 07896 BPL SKIP182 ; %00 -> Copy next word to title line
B29E 5008 07897 BVC SKIP183 ; %01 -> End-of-phrase, short delay, hide title line
B2A0 A9FE 07898 LDA #254 ; Title segment lifetime := 60 game loops
B2A2 5096 07899 SKIP182 BVC SKIP177 ; %10 -> End-of-segment.
B2A4 A0FF 07900 LDY #$FF ; Title segment lifetime := 60 game loops
B2A6 84D1 07901 STY TITLEPHR ; %11 -> End-of-phrase, long delay, hide title line
B2A8 85CF 07902 SKIP183 STA TITLELIFE ; Title segment lifetime := 254 game loops
B2AA 60 07903 RTS ; Return
07904
07905 ;*******************************************************************************
07906 ;* *
07907 ;* SOUND *
07908 ;* *
07909 ;* Handle sound effects *
07910 ;* *
07911 ;*******************************************************************************
07912
07913 ; DESCRIPTION
07914 ;
07915 ; This subroutine handles the sound effects. It is called every vertical blank
07916 ; phase, that is, every TICK (1/60 s on an NTSC Atari 8-bit Home Computer
07917 ; system, 1/50 s on a PAL Atari 8-bit Home Computer system) from the Vertical
07918 ; Blank Interrupt handler VBIHNDLR ($A6D1).
07919 ;
07920 ; The game uses all of the available 4 audio channels: Audio channels 1, 2, and
07921 ; 3 are shared among the Engines sound effects and the "noise sound patterns"
07922 ; (explosion and photon torpedo sound effects), while audio channel 4 is used
07923 ; for "beeper sound patterns" (status report sound effects). The following
07924 ; sections explain the beeper sound patterns and the noise sound patterns:
07925 ;
07926 ; o BEEPER SOUND PATTERNS
07927 ;
07928 ; There are the following beeper sound patterns:
07929 ;
07930 ; (1) HYPERWARP TRANSIT
07931 ; (2) RED ALERT
07932 ; (3) ACKNOWLEDGE
07933 ; (4) DAMAGE REPORT
07934 ; (5) MESSAGE FROM STARBASE
07935 ;
07936 ; They are encoded in table BEEPPATTAB ($BF3E) in 6-byte long "beeper sound
07937 ; patterns".
07938 ;
07939 ; Another table, BEEPFRQTAB ($BF5C), stores the frequencies for the tones
07940 ; of each beeper sound pattern, terminated by a marker byte ($FF).
07941 ;
07942 ; BUG (at $BF5C): The pattern frequencies in table BEEPFRQTAB ($BF5C) at
07943 ; offset $00 are unused. Suggested Fix: Remove from code.
07944 ;
07945 ; Whenever the game calls subroutine BEEP ($B3A6), that subroutine sets up a
07946 ; beeper sound pattern for playing by copying 6 bytes from the pattern table
07947 ; BEEPPATTAB ($BF3E) to BEEPFRQIND ($D2)..BEEPFRQSTART ($D7). Subroutine
07948 ; SOUND ($B2AB) detects the copied beeper sound pattern and plays the
07949 ; encoded tones and pauses.
07950 ;
07951 ; The relevant variables for playing a beeper sound pattern are the
07952 ; following (see also figures at BEEPPATTAB ($BF3E)):
07953 ;
07954 ; BEEPFRQIND ($D2) = Running index into table BEEPFRQTAB ($BF5C)
07955 ; BEEPREPEAT ($D3) = Number of times that the beeper sound pattern is
07956 ; repeated - 1
07957 ; BEEPTONELIFE ($D4) = Lifetime of tone in TICKs - 1
07958 ; BEEPPAUSELIFE ($D5) = Lifetime of pause in TICKs - 1 ($FF -> No pause)
07959 ; BEEPPRIORITY ($D6) = Beeper sound pattern priority. A playing beeper
07960 ; sound pattern is stopped if a beeper sound pattern
07961 ; of higher priority is about to be played. A value
07962 ; of 0 indicates that no beeper sound pattern is
07963 ; playing at the moment.
07964 ; BEEPFRQSTART ($D7) = Index to first byte of the beeper sound pattern in
07965 ; table BEEPFRQTAB ($BF5C)
07966 ;
07967 ; BEEPLIFE ($D8) = Lifetime of the current tone or pause in TICKs
07968 ; BEEPTOGGLE ($D9) = Indicates that either a tone (0) or a pause (not
07969 ; 0) is currently playing.
07970 ;
07971 ; o NOISE SOUND PATTERNS
07972 ;
07973 ; There are the following noise sound patterns:
07974 ;
07975 ; (1) PHOTON TORPEDO LAUNCHED
07976 ; (2) SHIELD EXPLOSION
07977 ; (3) ZYLON EXPLOSION
07978 ;
07979 ; They are encoded in table NOISEPATTAB ($BF20) in 10-byte long "noise sound
07980 ; patterns".
07981 ;
07982 ; Whenever the game calls subroutine NOISE ($AEA8), that subroutine sets up
07983 ; a noise sound pattern for being played by copying 10 bytes from the
07984 ; pattern table NOISEPATTAB ($BF20) to NOISETORPTIM ($DA)..NOISELIFE ($E1)
07985 ; and hardware sound registers AUDCTL ($D208) and AUDF3 ($D204).
07986 ;
07987 ; The relevant variables for playing a noise sound pattern are the
07988 ; following:
07989 ;
07990 ; NOISETORPTIM ($DA) = Delay timer for PHOTON TORPEDO LAUNCHED noise
07991 ; sound pattern
07992 ; NOISEEXPLTIM ($DB) = Delay timer for SHIELD EXPLOSION and ZYLON
07993 ; EXPLOSION noise sound patterns
07994 ; NOISEAUDC2 ($DC) = Audio channel 1/2 control shadow register
07995 ; NOISEAUDC3 ($DD) = Audio channel 3 control shadow register
07996 ; NOISEAUDF1 ($DE) = Audio channel 1 frequency shadow register
07997 ; NOISEAUDF2 ($DF) = Audio channel 2 frequency shadow register
07998 ; NOISEFRQINC ($E0) = Audio channel 1/2 frequency increment
07999 ; NOISELIFE ($E1) = Noise sound pattern lifetime
08000 ;
08001 ; AUDCTL ($D208) = POKEY: Audio control
08002 ; AUDF3 ($D204) = POKEY: Audio channel 3 frequency audio register
08003 ;
08004 ; There are two more variables that trigger noise effects. They are not part
08005 ; of the noise sound pattern table:
08006 ;
08007 ; NOISEZYLONTIM ($E2) = Delay timer to trigger the ZYLON EXPLOSION noise
08008 ; sound pattern. It is set in subroutine COLLISION
08009 ; ($AF3D) when the impact of one of our starship's
08010 ; photon torpedoes with a target is imminent. The
08011 ; timer is decremented every TICK. When it reaches a
08012 ; value of 0 the ZYLON EXPLOSION noise sound pattern
08013 ; is played in subroutine SOUND ($B2AB).
08014 ; NOISEHITLIFE ($E3) = Lifetime of the STARSHIP EXPLOSION noise when our
08015 ; starship was destroyed by a Zylon photon torpedo.
08016 ; It is set in GAMELOOP ($A1F3) to a value of 64
08017 ; TICKs. When it reaches a value of 0 the STARSHIP
08018 ; EXPLOSION noise is played in subroutine SOUND
08019 ; ($B2AB).
08020 ;
08021 ; SUBROUTINE DETAILS
08022 ;
08023 ; This subroutine executes the following steps:
08024 ;
08025 ; (1) Play beeper sound pattern
08026 ;
08027 ; The playing of a beeper sound pattern is started, continued, or stopped.
08028 ;
08029 ; (2) Play ZYLON EXPLOSION noise sound pattern
08030 ;
08031 ; If the explosion of a target space object is imminent (subroutine
08032 ; COLLISION ($AF3D) has set NOISEZYLONTIM ($E2) to the number of game loop
08033 ; iterations that will pass until our starship's photon torpedo will hit
08034 ; the target), the timer NOISEZYLONTIM ($E2) is decremented every TICK. If
08035 ; it reaches a value of 0, then the noise sound pattern ZYLON EXPLOSION is
08036 ; played.
08037 ;
08038 ; (3) Play starship's Engines sound
08039 ;
08040 ; If the Engines are louder than the current noise sound pattern then the
08041 ; noise sound pattern is terminated and the values for the audio channels
08042 ; 1..3 are updated:
08043 ;
08044 ; The velocity of our starship determines the pitch and the volume of the
08045 ; Engines: the higher the velocity, the higher the pitch and the volume of
08046 ; the Engines. The incremented value of VELOCITYLO ($70) is used as a "base
08047 ; value" %abcdefgh.
08048 ;
08049 ; Audio channels 1 and 2 are combined to a 16-bit audio channel 1/2,
08050 ; clocked at 1.79 MHz. The inverted bits (represented by an overscore)
08051 ; B7..0 of the base value form bits B12..5 of the 16-bit frequency value of
08052 ; audio channel 1/2. Bits B7..4 of the base value form bits B3..0 of the
08053 ; volume of audio channel 1/2, with noise distortion bit B7 set:
08054 ; ________
08055 ; AUDF1/2 ($D202..3) := %000abcdefgh00000
08056 ; AUDC2 ($D203) := %1000abcd
08057 ;
08058 ; Audio channel 3 is also clocked at 1.79 MHz. The inverted bits B7..0 of
08059 ; the base value form bits B7..0 of the frequency value of audio channel 3.
08060 ; Bits B6..4 of the base value form bits B3..0 of the volume of audio
08061 ; channel 3, with noise distortion bit B7 set:
08062 ; ________
08063 ; AUDF3 ($D204) := %abcdefgh
08064 ; AUDC3 ($D205) := %10000bcd
08065 ;
08066 ; Code execution returns at this point.
08067 ;
08068 ; (4) Play ZYLON EXPLOSION or SHIELD EXPLOSION noise sound pattern
08069 ;
08070 ; If the ZYLON EXPLOSION or SHIELD EXPLOSION noise sound pattern was set
08071 ; up, the explosion noise timer NOISEEXPLTIM ($DB) is decremented every
08072 ; TICK. It starts either with a value of 4 TICKs with a ZYLON EXPLOSION
08073 ; noise sound pattern or with a value of 8 TICKs with a SHIELD EXPLOSION
08074 ; noise sound pattern, set up in subroutine NOISE ($AEA8). If it reaches a
08075 ; value of 0, then the shadow control register of audio channel 1/2
08076 ; switches to "noise distortion" at maximum volume.
08077 ;
08078 ; (5) Play PHOTON TORPEDO LAUNCHED noise sound pattern
08079 ;
08080 ; If the PHOTON TORPEDO LAUNCHED noise sound pattern was set up, the photon
08081 ; torpedo noise timer NOISETORPTIM ($DA) is decremented every TICK. It
08082 ; starts with a value of 8 TICKs, set in subroutine TRIGGER ($AE29). The
08083 ; noise distortion and volume for the shadow control register of audio
08084 ; channel 3 is picked from table NOISETORPVOLTAB ($BFEB), the noise
08085 ; frequency for audio channel 3 is picked from table NOISETORPFRQTAB
08086 ; ($BFF3). If the photon torpedo noise timer reaches a value of 0, then the
08087 ; shadow control registers of audio channel 1/2 switch to "tone distortion"
08088 ; at maximum volume and a frequency of $0202.
08089 ;
08090 ; NOTE: Using a real-time volume envelope stored in table NOISETORPVOLTAB
08091 ; ($BFEB) for a launched photon torpedo results in producing the
08092 ; distinctive "whooshing" photon torpedo sound.
08093 ;
08094 ; (6) Play STARSHIP EXPLOSION noise
08095 ;
08096 ; If our starship was hit by a Zylon photon torpedo then NOISEHITLIFE ($E3)
08097 ; was set to 64 TICKs in routine GAMELOOP ($A1F3). While this value is
08098 ; decremented every TICK, a random frequency value is stored to audio
08099 ; channel 3 and the distortion bit of the shadow control register of audio
08100 ; channel 3 is randomly toggled.
08101 ;
08102 ; (7) Increase audio channels 1/2 frequency
08103 ;
08104 ; The 16-bit frequency value of audio channels 1/2 (both shadow registers
08105 ; and audio registers) is increased every TICK by an increment picked from
08106 ; the currently playing noise sound pattern.
08107 ;
08108 ; (8) Mute audio channels gradually
08109 ;
08110 ; Toward the end of a noise sound pattern's lifetime all audio channels
08111 ; gradually mute their volume every other TICK until completely silent.
08112
08113 ;*** Play beeper sound pattern *************************************************
B2AB A5D6 08114 SOUND LDA BEEPPRIORITY ; Skip if beeper sound pattern not in use
B2AD F037 08115 BEQ SKIP185 ;
08116
B2AF C6D8 08117 DEC BEEPLIFE ; Decrement beeper lifetime
B2B1 1033 08118 BPL SKIP185 ; Skip if beeper lifetime still counting down
08119
B2B3 A5D9 08120 LDA BEEPTOGGLE ; Load tone/pause toggle
B2B5 F00A 08121 BEQ LOOP058 ; Skip if a tone is playing or is to be played
08122
B2B7 A5D5 08123 LDA BEEPPAUSELIFE ; Load pause lifetime
B2B9 3006 08124 BMI LOOP058 ; Skip if duration = $FF (no pause)
B2BB 85D8 08125 STA BEEPLIFE ; Store pause lifetime as beeper lifetime
B2BD A000 08126 LDY #0 ; Prep AUDC4 (zero volume)
B2BF F020 08127 BEQ SKIP184 ; Skip unconditionally
08128
B2C1 A5D4 08129 LOOP058 LDA BEEPTONELIFE ; Load tone lifetime
B2C3 85D8 08130 STA BEEPLIFE ; Store tone lifetime as beeper lifetime
B2C5 A6D2 08131 LDX BEEPFRQIND ; Load frequency index
B2C7 E6D2 08132 INC BEEPFRQIND ; Increment frequency index
B2C9 BD5CBF 08133 LDA BEEPFRQTAB,X ; Store tone frequency from frequency table in AUDF4
B2CC 8D06D2 08134 STA AUDF4 ;
B2CF A0A8 08135 LDY #$A8 ; Prep AUDC4 (tone distortion + medium volume)
B2D1 C9FF 08136 CMP #$FF ; Skip if frequency not $FF (there are more tones)
B2D3 D00C 08137 BNE SKIP184 ;
08138
B2D5 A5D7 08139 LDA BEEPFRQSTART ; Rewind pattern frequency pointer
B2D7 85D2 08140 STA BEEPFRQIND ;
B2D9 C6D3 08141 DEC BEEPREPEAT ; Decrement sequence counter
B2DB 10E4 08142 BPL LOOP058 ; Keep playing until sequence counter < 0
08143
B2DD A000 08144 LDY #0 ; Prep AUDC4 with zero volume
B2DF 84D6 08145 STY BEEPPRIORITY ; Stop playing beeper sound pattern
08146
B2E1 8C07D2 08147 SKIP184 STY AUDC4 ; Store in AUDC4
B2E4 84D9 08148 STY BEEPTOGGLE ; Store in BEEPTOGGLE
08149
08150 ;*** Play ZYLON EXPLOSION noise sound pattern **********************************
B2E6 A5E2 08151 SKIP185 LDA NOISEZYLONTIM ; Skip if ZYLON EXPLOSION timer not in use
B2E8 F009 08152 BEQ SKIP186 ;
08153
B2EA C6E2 08154 DEC NOISEZYLONTIM ; Decrement ZYLON EXPLOSION timer
B2EC D005 08155 BNE SKIP186 ; Skip if ZYLON EXPLOSION timer still counting down
08156
B2EE A214 08157 LDX #$14 ; Play noise sound pattern ZYLON EXPLOSION
B2F0 20A8AE 08158 JSR NOISE ;
08159
08160 ;*** Play our starship's Engines sound *****************************************
B2F3 A670 08161 SKIP186 LDX VELOCITYLO ; Skip if Engines softer than noise sound pattern
B2F5 8A 08162 TXA ;
B2F6 4A 08163 LSR A ;
B2F7 4A 08164 LSR A ;
B2F8 4A 08165 LSR A ;
B2F9 4A 08166 LSR A ;
B2FA 4A 08167 LSR A ;
B2FB C5E1 08168 CMP NOISELIFE ;
B2FD 902C 08169 BCC SKIP187 ;
08170
B2FF A900 08171 LDA #0 ; Terminate noise sound pattern
B301 85E1 08172 STA NOISELIFE ;
08173
B303 E8 08174 INX ;
B304 8A 08175 TXA ; A := %abcdefgh = VELOCITYLO + 1
B305 49FF 08176 EOR #$FF ; ________
B307 8D04D2 08177 STA AUDF3 ; AUDF3 := %abcdefgh
08178
B30A AA 08179 TAX ; ________
B30B 0A 08180 ASL A ; AUDF2/1 := %000abcdefgh00000
B30C 0A 08181 ASL A ;
B30D 0A 08182 ASL A ;
B30E 0A 08183 ASL A ;
B30F 0A 08184 ASL A ;
B310 8D00D2 08185 STA AUDF1 ;
B313 8A 08186 TXA ;
B314 4A 08187 LSR A ;
B315 4A 08188 LSR A ;
B316 4A 08189 LSR A ;
B317 8D02D2 08190 STA AUDF2 ;
08191
B31A 4A 08192 LSR A ; AUDC2 := %1000abcd
B31B 498F 08193 EOR #$8F ; (noise distortion + B7..B4 bits for volume)
B31D 8D03D2 08194 STA AUDC2 ;
08195
B320 2987 08196 AND #$87 ; AUDC3 := %10000bcd
B322 8D05D2 08197 STA AUDC3 ; (noise distortion + B6..B4 bits for volume)
08198
B325 A970 08199 LDA #$70 ; Clock audio channel 1 and 3 @ 1.79 MHz and...
B327 8D08D2 08200 STA AUDCTL ; ...combine audio channel 1/2 to 16-bit channel
08201
B32A 60 08202 RTS ; Return
08203
08204 ;*** Play ZYLON EXPLOSION or SHIELD EXPLOSION noise ****************************
B32B A5DB 08205 SKIP187 LDA NOISEEXPLTIM ; Skip if explosion noise timer not in use
B32D F008 08206 BEQ SKIP188 ;
08207
B32F C6DB 08208 DEC NOISEEXPLTIM ; Decrement explosion noise timer (4 or 8 TICKs long)
B331 D004 08209 BNE SKIP188 ; Skip if explosion noise timer still counting down
08210
B333 A98F 08211 LDA #$8F ; Shadow register AUDC2 := (noise dist. + max volume)
B335 85DC 08212 STA NOISEAUDC2 ;
08213
08214 ;*** Play PHOTON TORPEDO LAUNCHED noise sound **********************************
B337 A6DA 08215 SKIP188 LDX NOISETORPTIM ; Skip if photon torpedo noise timer not in use
B339 F01C 08216 BEQ SKIP190 ;
08217
B33B C6DA 08218 DEC NOISETORPTIM ; Decrement photon torpedo noise timer (8 TICKs long)
B33D D00A 08219 BNE SKIP189 ; Skip if torpedo noise timer still counting down
08220
B33F A9AF 08221 LDA #$AF ; Shadow register AUDC2 := (tone dist. + max volume)
B341 85DC 08222 STA NOISEAUDC2 ;
B343 A902 08223 LDA #$02 ; Set frequency $0202 to AUDF1/2's shadow...
B345 85DE 08224 STA NOISEAUDF1 ; ...registers
B347 85DF 08225 STA NOISEAUDF2 ;
08226
B349 BDEABF 08227 SKIP189 LDA NOISETORPVOLTAB-1,X ; Pick torpedo noise + volume shape (X in 1..8)...
B34C 85DD 08228 STA NOISEAUDC3 ; ...and store it in AUDC3's shadow register
B34E BDF2BF 08229 LDA NOISETORPFRQTAB-1,X ; Pick photon torpedo noise frequency (X in 1..8)...
B351 8D04D2 08230 STA AUDF3 ; ...and store it in AUDF3
B354 8D09D2 08231 STA STIMER ; Reset POKEY audio timers
08232
08233 ;*** Play STARSHIP EXPLOSION noise when our starship is hit ********************
B357 A5E3 08234 SKIP190 LDA NOISEHITLIFE ; Skip if STARSHIP EXPLOSION noise not in use
B359 F00E 08235 BEQ SKIP191 ;
08236
B35B C6E3 08237 DEC NOISEHITLIFE ; Decrement STARSHIP EXPLOSION noise lifetime
B35D AD0AD2 08238 LDA RANDOM ; Set random frequency to AUDF3
B360 8D04D2 08239 STA AUDF3 ;
B363 2920 08240 AND #$20 ; Toggle noise/tone dist. of AUDC3's shadow register
B365 45DD 08241 EOR NOISEAUDC3 ; ...randomly
B367 85DD 08242 STA NOISEAUDC3 ;
08243
08244 ;*** Increase 16-bit frequency of audio channels 1/2 (shadow registers also) ***
B369 18 08245 SKIP191 CLC ; Increase 16-bit frequency value of AUDF1/2...
B36A A5DE 08246 LDA NOISEAUDF1 ; ...and its shadow register by...
B36C 65E0 08247 ADC NOISEFRQINC ; ...noise sound pattern frequency increment
B36E 85DE 08248 STA NOISEAUDF1 ; AUDF1/2 := NOISEAUDF1/2 := ...
B370 8D00D2 08249 STA AUDF1 ; ...NOISEAUDF1/2 + NOISEFRQINC
B373 A5DF 08250 LDA NOISEAUDF2 ;
B375 6900 08251 ADC #0 ;
B377 85DF 08252 STA NOISEAUDF2 ;
B379 8D02D2 08253 STA AUDF2 ;
08254
08255 ;*** Gradually mute audio channels while noise sound pattern expires ***********
B37C A6DC 08256 LDX NOISEAUDC2 ; Prep AUDC2's shadow register value
B37E A4DD 08257 LDY NOISEAUDC3 ; Prep AUDC3's shadow register value
08258
B380 A572 08259 LDA COUNT8 ; Decrement volumes every other TICK
B382 4A 08260 LSR A ;
B383 901A 08261 BCC SKIP193 ;
08262
B385 A5E1 08263 LDA NOISELIFE ; Skip if noise sound pattern not in use
B387 F016 08264 BEQ SKIP193 ;
08265
B389 C6E1 08266 DEC NOISELIFE ; Decrement noise sound pattern lifetime
08267
B38B C911 08268 CMP #17 ; Mute noise sound pattern only in...
B38D B010 08269 BCS SKIP193 ; ...the last 16 TICKs of its lifetime
08270
B38F 8A 08271 TXA ; Decrement volume of AUDC2's shadow register
B390 290F 08272 AND #$0F ;
B392 F003 08273 BEQ SKIP192 ;
B394 CA 08274 DEX ;
B395 86DC 08275 STX NOISEAUDC2 ;
08276
B397 98 08277 SKIP192 TYA ; Decrement volume of AUDC3's shadow register
B398 290F 08278 AND #$0F ;
B39A F003 08279 BEQ SKIP193 ;
B39C 88 08280 DEY ;
B39D 84DD 08281 STY NOISEAUDC3 ;
08282
B39F 8E03D2 08283 SKIP193 STX AUDC2 ; Store shadow register values to audio registers
B3A2 8C05D2 08284 STY AUDC3 ;
08285
B3A5 60 08286 RTS ; Return
08287
08288 ;*******************************************************************************
08289 ;* *
08290 ;* BEEP *
08291 ;* *
08292 ;* Copy beeper sound pattern *
08293 ;* *
08294 ;*******************************************************************************
08295
08296 ; DESCRIPTION
08297 ;
08298 ; Copies a 6-byte beeper sound pattern from beeper sound pattern table
08299 ; BEEPPATTAB ($BF3E) to BEEPFRQIND ($D2)..BEEPFRQSTART ($D7), provided that no
08300 ; beeper sound pattern with higher priority is currently playing. The beeper
08301 ; sound pattern will then be automatically played in subroutine SOUND ($B2AB).
08302 ; See subroutine SOUND ($B2AB) for more information on beeper sound patterns.
08303 ;
08304 ; NOTE: The bytes from table BEEPPATTAB ($BF3E) are copied in reverse order.
08305 ;
08306 ; INPUT
08307 ;
08308 ; X = Offset to beeper sound pattern in table BEEPPATTAB ($BF3E). Used values
08309 ; are:
08310 ; $00 -> HYPERWARP TRANSIT
08311 ; $06 -> RED ALERT
08312 ; $0C -> ACKNOWLEDGE
08313 ; $12 -> DAMAGE REPORT
08314 ; $18 -> MESSAGE FROM STARBASE
08315
B3A6 BD3EBF 08316 BEEP LDA BEEPPATTAB,X ; Return if beeper sound pattern of...
B3A9 C5D6 08317 CMP BEEPPRIORITY ; ...higher priority is playing
B3AB 900C 08318 BCC SKIP194 ;
08319
B3AD A005 08320 LDY #5 ; Copy 6-byte beeper sound pattern (in reverse order)
B3AF BD3EBF 08321 LOOP059 LDA BEEPPATTAB,X ;
B3B2 99D200 08322 STA BEEPFRQIND,Y ;
B3B5 E8 08323 INX ;
B3B6 88 08324 DEY ;
B3B7 10F6 08325 BPL LOOP059 ;
08326
B3B9 60 08327 SKIP194 RTS ; Return
08328
08329 ;*******************************************************************************
08330 ;* *
08331 ;* INITIALIZE *
08332 ;* *
08333 ;* More game initialization *
08334 ;* *
08335 ;*******************************************************************************
08336
08337 ; DESCRIPTION
08338 ;
08339 ; This subroutine executes the following initialization steps:
08340 ;
08341 ; (1) Set up Display List
08342 ;
08343 ; A Display List is created at DSPLST ($0280). It starts with 2 x 8 = 16
08344 ; blank video lines, followed by 90 GRAPHICS7 rows. After a deliberate gap
08345 ; in Display List instructions, which will be filled dynamically during the
08346 ; game by calls to subroutine MODDLST ($ADF1), it ends with a Display List
08347 ; wait-and-jump-back instruction to the start of the Display List at DSPLST
08348 ; ($0280).
08349 ;
08350 ; NOTE: The PLAYFIELD color table PFCOLORTAB ($BFA9) is copied to zero page
08351 ; table PF0COLOR ($F2) by loop jamming.
08352 ;
08353 ; (2) Create lookup tables
08354 ;
08355 ; The first lookup table MAPTO80 ($0DE9) maps a byte value of 0..255 to
08356 ; 0..80. This table is used to map unsigned (absolute) position vector
08357 ; components (coordinates) to pixel (or PLAYER) row and column numbers.
08358 ;
08359 ; NOTE: The PLAYFIELD is 160 pixels wide. Pixel column numbers relative the
08360 ; horizontal PLAYFIELD center are in -80..79, hence the range of this
08361 ; lookup table. Pixel row numbers relative the vertical PLAYFIELD center
08362 ; are in -50..49, thus they also fit in the range of this lookup table.
08363 ;
08364 ; The second lookup table MAPTOBCD99 ($0EE9) maps a byte value of 0..255 to
08365 ; a BCD-encoded value in 00..99. This table is used to convert byte values
08366 ; into decimal 2-digit values displayed by the THETA (in "gradons"), PHI
08367 ; (in "gradons"), RANGE (in "centrons"), and VELOCITY (in "metrons per
08368 ; second") readouts of the Console Panel Display.
08369 ;
08370 ; The third and fourth lookup tables accelerate drawing of PLAYFIELD space
08371 ; objects: In combination they contain the 16-bit start addresses of each
08372 ; of the 100 rows of PLAYFIELD memory. The low bytes of the 16-bit
08373 ; addresses are stored in table PFMEMROWLO ($0800). The high bytes are
08374 ; stored in table PFMEMROWHI ($0864).
08375 ;
08376 ; NOTE: The address increment is 40 (40 bytes = 160 pixels in GRAPHICS7
08377 ; mode = 1 PLAYFIELD row of pixels).
08378 ;
08379 ; NOTE: The PLAYFIELD consists of 90 GRAPHICS7 rows when the Control Panel
08380 ; Display is displayed at the bottom. When the Control Panel Display is not
08381 ; displayed, for example in demo mode, the PLAYFIELD contains additional
08382 ; GRAPHICS7 rows.
08383 ;
08384 ; (3) Copy Control Panel Display and Galactic Chart Panel Display texts
08385 ;
08386 ; The texts of the Control Panel Display and the Galactic Chart Panel
08387 ; Display are copied to their respective locations in memory by loop
08388 ; jamming.
08389 ;
08390 ; (4) Initialize Zylon unit movement timer
08391 ;
08392 ; The timer that triggers the movement of Zylon units in the Galactic Chart
08393 ; is initialized to a value of 99. See subroutine FLUSHGAMELOOP ($B4E4) for
08394 ; more information on Zylon unit movement.
08395 ;
08396 ; (5) Create Galactic Chart
08397 ;
08398 ; The Galactic Chart memory map GCMEMMAP ($08C9) is initialized. It
08399 ; represents 16 columns x 8 rows of sectors. Each sector contains one of
08400 ; the 4 sector types stored in table SECTORTYPETAB ($BBA6) (starbase, 4
08401 ; Zylon ships, 3 Zylon ships, and 2 or 1 Zylon ships), and empty sectors.
08402 ; Before distributing the sector types, the initial position of our
08403 ; starship is blocked on the Galactic Chart at sector row 4, sector column
08404 ; 8, so that it will not be inadvertently occupied while other sector types
08405 ; are distributed. The number of each of the sector types to be distributed
08406 ; is the mission level plus 2. While Zylon units can be placed anywhere,
08407 ; starbases are placed neither at the borders of the Galactic Chart nor in
08408 ; a sector adjacent to an occupied sector.
08409 ;
08410 ; After having initialized the Galactic Chart memory map, the top border of
08411 ; the Galactic Chart is drawn with characters from the custom character
08412 ; set.
08413 ;
08414 ; Finally, the sector in which our starship is located and the arrival and
08415 ; departure hyperwarp marker column and row numbers are initialized.
08416 ;
08417 ; (6) Apply a final tweak
08418 ;
08419 ; The last entry of lookup table MAPTOBCD99 ($0EE9) is tweaked to a value
08420 ; of CCS.INF * 16 + CCS.SPC. It is used to display an infinity symbol by
08421 ; the RANGE readout of the Control Panel Display in subroutine SHOWCOORD
08422 ; ($B8A7).
08423 ;
08424 ; Code execution continues into subroutine DRAWGC ($B4B9), which draws the
08425 ; content of the Galactic Chart with characters from the custom character set.
08426
=0068 08427 L.MEMPTR1 = $68 ; 16-bit memory pointer
=006A 08428 L.MEMPTR2 = $6A ; 16-bit memory pointer
=006A 08429 L.SECTORTYPE = $6A ; Saves sector type. Used values are:
08430 ; $CF -> Sector contains starbase
08431 ; $04 -> Sector contains 4 Zylon ships
08432 ; $03 -> Sector contains 3 Zylon ships
08433 ; $02 -> Sector contains 2 or 1 Zylon ships
=006B 08434 L.SECTORCNT = $6B ; Saves number of sectors of the current sector type
08435
08436 ;*** Initialize Display List and copy color table ******************************
B3BA A259 08437 INITIALIZE LDX #89 ; Set 89(+1) GRAPHICS7 rows from DSPLST+5 on
B3BC A90D 08438 LOOP060 LDA #$0D ; Prep DL instruction $0D (one row of GRAPHICS7)
B3BE 9D8502 08439 STA DSPLST+5,X ; DSPLST+5,X := one row of GRAPHICS7
B3C1 E00A 08440 CPX #10 ;
B3C3 B005 08441 BCS SKIP195 ;
B3C5 BDA9BF 08442 LDA PFCOLORTAB,X ; Copy PLAYFIELD color table to zero page table
B3C8 95F2 08443 STA PF0COLOR,X ; (loop jamming)
B3CA CA 08444 SKIP195 DEX ;
B3CB 10EF 08445 BPL LOOP060 ;
08446
B3CD A970 08447 LDA #$70 ; DSPLST := BLK8
B3CF 8D8002 08448 STA DSPLST ; DSPLST+1 := BLK8
B3D2 8D8102 08449 STA DSPLST+1 ;
B3D5 A941 08450 LDA #$41 ; DSPLST+103 := WAITJMP @ DSPLST
B3D7 8DE702 08451 STA DSPLST+103 ;
B3DA A980 08452 LDA #<DSPLST ;
B3DC 8DE802 08453 STA DSPLST+104 ;
B3DF A902 08454 LDA #>DSPLST ;
B3E1 8DE902 08455 STA DSPLST+105 ;
08456
08457 ;*** Calculate lookup tables ***************************************************
B3E4 A200 08458 LDX #0 ; Clear both 16-bit memory pointers
B3E6 8668 08459 STX L.MEMPTR1 ;
B3E8 8669 08460 STX L.MEMPTR1+1 ;
B3EA 866A 08461 STX L.MEMPTR2 ;
B3EC 866B 08462 STX L.MEMPTR2+1 ;
08463
08464 ;*** Calc MAPTO80 map (converts value of $00..$FF to value in 0..80) ***********
B3EE 18 08465 LOOP061 CLC ;
B3EF A568 08466 LDA L.MEMPTR1 ;
B3F1 6951 08467 ADC #81 ;
B3F3 8568 08468 STA L.MEMPTR1 ;
B3F5 A569 08469 LDA L.MEMPTR1+1 ;
B3F7 9DE90D 08470 STA MAPTO80,X ;
B3FA 6900 08471 ADC #0 ;
B3FC 8569 08472 STA L.MEMPTR1+1 ;
08473
08474 ;*** Calc MAPTOBCD99 map (converts value of $00..$FF to BCD-value in 00..99) ***
B3FE 18 08475 CLC ;
B3FF A56A 08476 LDA L.MEMPTR2 ;
B401 6964 08477 ADC #100 ;
B403 856A 08478 STA L.MEMPTR2 ;
B405 A56B 08479 LDA L.MEMPTR2+1 ;
B407 9DE90E 08480 STA MAPTOBCD99,X ;
B40A F8 08481 SED ;
B40B 6900 08482 ADC #0 ;
B40D D8 08483 CLD ;
B40E 856B 08484 STA L.MEMPTR2+1 ;
B410 E8 08485 INX ;
B411 D0DB 08486 BNE LOOP061 ;
08487
08488 ;*** Calculate PLAYFIELD memory row addresses, copy Panel Display texts ********
B413 A200 08489 LDX #<PFMEM ; Point L.MEMPTR1 to start of PLAYFIELD memory
B415 8668 08490 STX L.MEMPTR1 ; (X = 0, because PFMEM is at $1000)
B417 A910 08491 LDA #>PFMEM ;
B419 8569 08492 STA L.MEMPTR1+1 ;
08493
B41B 18 08494 LOOP062 CLC ;
B41C A568 08495 LDA L.MEMPTR1 ;
B41E 9D0008 08496 STA PFMEMROWLO,X ; Store 16-bit value of L.MEMPTR1 in PFMEMROWHI/LO
B421 6928 08497 ADC #40 ; Add 40 to L.MEMPTR
B423 8568 08498 STA L.MEMPTR1 ; (40 bytes = 160 pixels = 1 PLAYFIELD row)
B425 A569 08499 LDA L.MEMPTR1+1 ;
B427 9D6408 08500 STA PFMEMROWHI,X ;
B42A 6900 08501 ADC #0 ;
B42C 8569 08502 STA L.MEMPTR1+1 ;
08503
B42E BD42BB 08504 LDA PANELTXTTAB,X ; Copy Control and Galactic Chart Panel Display texts
B431 9D4909 08505 STA PANELTXT,X ; (loop jamming)
08506
B434 E8 08507 INX ;
B435 E064 08508 CPX #100 ;
B437 90E2 08509 BCC LOOP062 ; Loop 100 times
08510
08511 ;*** Set Zylon unit movement timer *********************************************
B439 CA 08512 DEX ;
B43A 8678 08513 STX ZYLONUNITTIM ; Init Zylon unit movement timer to 99 game loops
08514
08515 ;*** Create memory map of the Galactic Chart ***********************************
B43C A203 08516 LDX #3 ; Loop over all 3(+1) sector types
B43E 8E1109 08517 STX GCMEMMAP+4*16+8 ; Block our starship's initial position at center of
08518 ; ...Galactic Chart (sector row 4, sector column 8)
08519
B441 BDA6BB 08520 LOOP063 LDA SECTORTYPETAB,X ; Prep sector type
B444 856A 08521 STA L.SECTORTYPE ;
08522
B446 A462 08523 LDY MISSIONLEVEL ; Number sectors of current type := mission level + 2
B448 C8 08524 INY ;
B449 C8 08525 INY ;
B44A 846B 08526 STY L.SECTORCNT ;
08527
B44C AD0AD2 08528 LOOP064 LDA RANDOM ; Load random sector 0..127 from GC memory map
B44F 297F 08529 AND #$7F ;
B451 A8 08530 TAY ;
B452 B9C908 08531 LDA GCMEMMAP,Y ;
B455 D0F5 08532 BNE LOOP064 ; If sector already occupied, pick another
08533
B457 A56A 08534 LDA L.SECTORTYPE ; Reload sector type
B459 1021 08535 BPL SKIP196 ; Skip if sector not to be occupied by starbase
08536
B45B C010 08537 CPY #$10 ; Place starbase...
B45D 90ED 08538 BCC LOOP064 ; ...not in first sector row of Galactic Chart
B45F C070 08539 CPY #$70 ;
B461 B0E9 08540 BCS LOOP064 ; ...not in last sector row of Galactic Chart
B463 98 08541 TYA ;
B464 290F 08542 AND #$0F ;
B466 F0E4 08543 BEQ LOOP064 ; ...not in first sector column of Galactic Chart
B468 C90F 08544 CMP #15 ;
B46A F0E0 08545 BEQ LOOP064 ; ...not in last sector column of Galactic Chart
B46C B9C808 08546 LDA GCMEMMAP-1,Y ; ...not east of an occupied sector
B46F 19CA08 08547 ORA GCMEMMAP+1,Y ; ...not west of an occupied sector
B472 19D908 08548 ORA GCMEMMAP+16,Y ; ...not south of an occupied sector
B475 19B908 08549 ORA GCMEMMAP-16,Y ; ...not north of an occupied sector
B478 D0D2 08550 BNE LOOP064 ;
08551
B47A A56A 08552 LDA L.SECTORTYPE ; Reload sector type
08553
B47C 99C908 08554 SKIP196 STA GCMEMMAP,Y ; Store sector type in Galactic Chart memory map
B47F C66B 08555 DEC L.SECTORCNT ;
B481 10C9 08556 BPL LOOP064 ; Next sector
B483 CA 08557 DEX ;
B484 10BB 08558 BPL LOOP063 ; Next sector type
08559
08560 ;*** Clear Galactic Chart and draw top border **********************************
B486 A2B4 08561 LDX #180 ; Clear Galactic Chart PLAYFIELD
B488 A90A 08562 LOOP065 LDA #CCS.SPC ;
B48A 9D340D 08563 STA GCPFMEM-1,X ;
B48D CA 08564 DEX ;
B48E D0F8 08565 BNE LOOP065 ;
08566
B490 A20F 08567 LDX #15 ; Draw top border (15(+1) characters)
B492 A918 08568 LOOP066 LDA #CCS.BORDERS ;
B494 9D370D 08569 STA GCPFMEM+2,X ;
B497 CA 08570 DEX ;
B498 10F8 08571 BPL LOOP066 ;
08572
B49A A91A 08573 LDA #CCS.CORNERSW ; Draw NORTHEAST corner (1 character)
B49C 8D470D 08574 STA GCPFMEM+18 ;
08575
B49F A900 08576 LDA #0 ; Release starship's position at center of Galactic
B4A1 8D1109 08577 STA GCMEMMAP+4*16+8 ; ...Chart (sector row 4, sector column 8)
08578
08579 ;*** Initialize current sector and hyperwarp marker column and row numbers *****
B4A4 A948 08580 LDA #$48 ; Place our starship's current sector at
B4A6 8590 08581 STA CURRSECTOR ; ...sector row 4, sector column 8
B4A8 A943 08582 LDA #$43 ; Init departure & arrival hyperwarp marker column
B4AA 858D 08583 STA WARPDEPRCOLUMN ;
B4AC 858F 08584 STA WARPARRVCOLUMN ;
B4AE A947 08585 LDA #$47 ; Init departure & arrival hyperwarp marker row
B4B0 858E 08586 STA WARPARRVROW ;
B4B2 858C 08587 STA WARPDEPRROW ;
08588
08589 ;*** Tweak last entry of MAPTOBCD99 ********************************************
B4B4 A9EA 08590 LDA #CCS.INF*16+CCS.SPC ; Last entry of MAPTOBCD99: 'INFINITY'+'SPACE' char
B4B6 8DE80F 08591 STA MAPTOBCD99+255 ;
08592
08593 ;*******************************************************************************
08594 ;* *
08595 ;* DRAWGC *
08596 ;* *
08597 ;* Draw Galactic Chart *
08598 ;* *
08599 ;*******************************************************************************
08600
08601 ; DESCRIPTION
08602 ;
08603 ; Draws the content of the Galactic Chart memory map in GCMEMMAP ($08C9) to the
08604 ; Galactic Chart PLAYFIELD memory at GCPFMEM ($0D35).
08605 ;
08606 ; NOTE: CPU register X indexes the Galactic Chart memory map GCMEMMAP ($08C9)
08607 ; (16 x 8 bytes). CPU register Y indexes the Galactic Chart PLAYFIELD memory
08608 ; GCPFMEM ($0D35) (20 x 9 bytes).
08609 ;
08610 ; NOTE: Sectors with 1 or 2 Zylon ships display the same symbol in the Galactic
08611 ; Chart.
08612
=006A 08613 L.GCMEMMAPIND = $6A ; Saves Galactic Chart memory map index
08614
B4B9 A000 08615 DRAWGC LDY #0 ; Clear Galactic Chart PLAYFIELD memory index
B4BB 846A 08616 STY L.GCMEMMAPIND ; Clear Galactic Chart memory map index
08617
B4BD A66A 08618 LOOP067 LDX L.GCMEMMAPIND ; Load sector of Galactic Chart memory map
B4BF BDC908 08619 LDA GCMEMMAP,X ;
B4C2 1002 08620 BPL SKIP197 ; Skip if not a starbase sector
B4C4 A905 08621 LDA #5 ; Prep sector character index for starbase
08622
B4C6 AA 08623 SKIP197 TAX ; Load sector character index
B4C7 BDD1BE 08624 LDA SECTORCHARTAB,X ; Load custom character set code from table...
B4CA 994B0D 08625 STA GCPFMEM+22,Y ; ...and store it in Galactic Chart PLAYFIELD memory
B4CD C8 08626 INY ; Increment Galactic Chart PLAYFIELD memory index
B4CE E66A 08627 INC L.GCMEMMAPIND ; Increment Galactic Chart memory map index
B4D0 A56A 08628 LDA L.GCMEMMAPIND ;
B4D2 290F 08629 AND #$0F ;
B4D4 D0E7 08630 BNE LOOP067 ; Next sector column until right border reached
08631
B4D6 A919 08632 LDA #CCS.BORDERW ; Draw right border
B4D8 994B0D 08633 STA GCPFMEM+22,Y ;
08634
B4DB C8 08635 INY ; Adjust Galactic Chart PLAYFIELD memory index
B4DC C8 08636 INY ;
B4DD C8 08637 INY ;
B4DE C8 08638 INY ;
B4DF C0A0 08639 CPY #$A0 ;
B4E1 90DA 08640 BCC LOOP067 ; Next sector until bottom-right sector reached
08641
B4E3 60 08642 RTS ; Return
08643
08644 ;*******************************************************************************
08645 ;* *
08646 ;* FLUSHGAMELOOP *
08647 ;* *
08648 ;* Handle remaining tasks at the end of a game loop iteration *
08649 ;* *
08650 ;*******************************************************************************
08651
08652 ; DESCRIPTION
08653 ;
08654 ; This subroutine handles at the end of a game loop iteration the following
08655 ; tasks:
08656 ;
08657 ; (1) Increment counters COUNT256 ($76) and COUNT8 ($72).
08658 ;
08659 ; (2) If our starship's energy has dropped below 1000 units then flash a {PINK}
08660 ; alert that changes to {DARK GREY BLUE} and back to {PINK} every 128 game
08661 ; loop iterations.
08662 ;
08663 ; (3) Set the Shields color and the Control Panel background color every 8 game
08664 ; loop iterations:
08665 ;
08666 ; o If the Shields are up and OK then set the Shields color to {DARK
08667 ; GREEN} and the Control Panel background color to {DARK BLUE}.
08668 ;
08669 ; o If the Shields are up and damaged there is a probability of 78%
08670 ; (200:256) that the Shield color is not changed.
08671 ;
08672 ; o If the Shields are down, damaged, or destroyed then set the Shields
08673 ; color to {BLACK}.
08674 ;
08675 ; o If the Shields are destroyed then set the Control Panel background
08676 ; color to {ORANGE}.
08677 ;
08678 ; (4) Decrement the lifetime of our starship's and Zylon photon torpedoes.
08679 ;
08680 ; (5) Decrement the lifetime of an explosion. If the explosion lifetime is less
08681 ; than 112 game loop iterations, clear HITBADNESS ($8A) (thus the explosion
08682 ; cannot destroy our starship). If the explosion lifetime is less than 24
08683 ; (?) game loops decrement the number of explosion fragments. This makes
08684 ; explosion fragments disappear gradually toward the end of an explosion.
08685 ;
08686 ; (6) Increment every 40 game loop iterations the stardate clock of the
08687 ; Galactic Chart Panel Display.
08688 ;
08689 ; (7) Move Zylon units in the Galactic Chart.
08690 ;
08691 ; Every 50 game loop iterations (or 100 game loop iterations when a
08692 ; starbase is surrounded by Zylon units) decrement the score.
08693 ;
08694 ; Code execution continues if the game is not in demo mode with the following
08695 ; steps:
08696 ;
08697 ; (1) Search the Galactic Chart for starbases surrounded by Zylon units.
08698 ; Destroy any such starbase: Replace it with a 2-Zylon sector and subtract
08699 ; 18 points from the score. If the Subspace Radio was not destroyed, then
08700 ; flash the title phrase "STARBASE DESTROYED" and play the beeper sound
08701 ; pattern MESSAGE FROM STARBASE in subroutine BEEP ($B3A6).
08702 ;
08703 ; (2) Every 8 game loop iterations the Zylon units decide, which starbase to
08704 ; hunt: First, 128 randomly picked sectors are searched for a starbase. If
08705 ; no starbase was found in this way, the sectors of the Galactic Chart are
08706 ; scanned systematically left-to-right, top-to-bottom. If a starbase was
08707 ; found then its sector, sector column, and sector row are saved, otherwise
08708 ; code execution returns.
08709 ;
08710 ; (3) Now the Zylon units converge toward the sector of the hunted starbase:
08711 ; All sectors of the Galactic Chart are scanned. For any sector with a
08712 ; Zylon unit that was not moved yet (its sector does not have the temporary
08713 ; "already-moved" bit B5 set) its movement probability value is picked from
08714 ; table MOVEPROBTAB ($BFBB):
08715 ;
08716 ; +---------------+-------------+----------------+
08717 ; | Sector Type | Movement | Movement |
08718 ; | | Probability | Probability |
08719 ; | | Value | |
08720 ; +---------------+-------------+----------------+
08721 ; | Empty sector | 0 | 0% ( 0:256) |
08722 ; | 1 Zylon ship | 255 | 100% (255:256) |
08723 ; | 2 Zylon ships | 255 | 100% (255:256) |
08724 ; | 3 Zylon ships | 192 | 75% (192:256) |
08725 ; | 4 Zylon ships | 32 | 13% ( 32:256) |
08726 ; +---------------+-------------+----------------+
08727 ;
08728 ; If this value is less or equal than a random number in 0..255 then the
08729 ; Zylon unit is moved to another sector. A Zylon unit that currently
08730 ; occupies the sector of our starship is not moved.
08731 ;
08732 ; BUG (at $B620): The instruction to check the marker bit B5 of the sector
08733 ; is CPY #$0A. This works, as sectors containing Zylon units that need to
08734 ; be moved have values of 2..4, see table SECTORTYPETAB ($BBA6). Suggested
08735 ; fix: Replace CPY #$0A with CPY #$20, which may make the code clearer.
08736 ;
08737 ; (4) For every Zylon unit that is about to be moved, 9 distances ("block
08738 ; distances") between the Zylon unit and the starbase are calculated by
08739 ; tentatively moving the Zylon unit into each of its 8 adjacent sectors -
08740 ; and by moving it not at all. The sector offsets are taken from table
08741 ; COMPASSOFFTAB ($BFC0) which stores direction offsets in the following
08742 ; order: NORTH, NORTHWEST, WEST, SOUTHWEST, SOUTH, SOUTHEAST, EAST,
08743 ; NORTHEAST, CENTER. All 9 distances are stored in 9 consecutive bytes at
08744 ; NEWZYLONDIST ($96).
08745 ;
08746 ; NOTE: The last calculated distance is the current distance between Zylon
08747 ; unit and starbase.
08748 ;
08749 ; The Zylon unit moves to the first of the 8 adjacent sectors that matches
08750 ; the following conditions:
08751 ;
08752 ; (1) It is closer to the starbase than the Zylon unit's current sector.
08753 ;
08754 ; (2) It is located inside the Galactic Chart.
08755 ;
08756 ; (3) It is empty.
08757 ;
08758 ; (4) It is not the sector containing our starship.
08759 ;
08760 ; If a suitable new sector was found then the Zylon unit is moved to this
08761 ; sector, which is marked with the "already-moved" marker bit B5 in the
08762 ; Galactic Chart memory map. This marker bit prevents a Zylon unit that has
08763 ; been already moved from being moved again. The old Zylon unit sector is
08764 ; cleared.
08765 ;
08766 ; If no suitable new sector was found then the above distance calculations
08767 ; are repeated once again by adding 1 to the current distance between the
08768 ; Zylon unit and the starbase. This may provoke a Zylon unit to move that
08769 ; would not have moved in the previous set of distance calculations.
08770 ;
08771 ; After having moved all Zylon units the sectors are stripped of the
08772 ; "already-moved" marker bit B5.
08773 ;
08774 ; (5) If a starbase has been surrounded then the Zylon unit movement timer is
08775 ; reset to 99, buying our starship some time to destroy one of the
08776 ; surrounding Zylon units. If the Subspace Radio is not destroyed, then the
08777 ; message "STARBASE SURROUNDED" is flashed in the title line and the beeper
08778 ; sound pattern MESSAGE FROM STARBASE is played in subroutine BEEP ($B3A6).
08779
=006A 08780 L.ISDESTROYED = $6A ; Flags the destruction of a starbase.
08781 ; Used values are:
08782 ; $00 -> Starbase not destroyed
08783 ; $02 -> Starbase has been destroyed
=006A 08784 L.NEWSECTOR = $6A ; Sector to which the Zylon unit is tentatively moved
=006B 08785 L.ABSDIFFCOLUMN = $6B ; Absolute difference between new Zylon and starbase
08786 ; column on Galactic Chart in PM pixels
=006B 08787 L.LOOPCNT2 = $6B ; Loop counter. Used values are: 0..1.
=006A 08788 L.DIRECTIONIND = $6A ; Compass rose direction index.
08789 ; Used values are: 0..7.
08790
08791 ;*** Increment counters and flash low-energy alert *****************************
B4E4 E676 08792 FLUSHGAMELOOP INC COUNT256 ; Increment COUNT256 counter
08793
B4E6 A290 08794 LDX #$90 ; Prep DLI background color {DARK GREY BLUE}
B4E8 A576 08795 LDA COUNT256 ;
B4EA 1009 08796 BPL SKIP198 ; Skip if counter < 128.
08797
B4EC AC5509 08798 LDY ENERGYD1 ; When energy drops below 1000 units...
B4EF C080 08799 CPY #CCS.COL2!CCS.0 ;
B4F1 D002 08800 BNE SKIP198 ;
B4F3 A244 08801 LDX #$44 ; ...prep new DLI background color {PINK}
08802
B4F5 2903 08803 SKIP198 AND #$03 ; Increment COUNT8
B4F7 8572 08804 STA COUNT8 ;
B4F9 D01F 08805 BNE SKIP202 ; Skip setting colors but every 8 game loops
08806
08807 ;*** Set Shields and Control Panel background color ****************************
B4FB A47D 08808 LDY DRAINSHIELDS ; Skip if Shields are off
B4FD F017 08809 BEQ SKIP201 ;
08810
B4FF A0A0 08811 LDY #$A0 ; Prep Shields color {DARK GREEN}
B501 2C9409 08812 BIT GCSTATSHL ; Skip if Shields are OK
B504 100B 08813 BPL SKIP200 ;
B506 7007 08814 BVS SKIP199 ; Skip if Shields are destroyed
B508 AD0AD2 08815 LDA RANDOM ; If Shields are damaged, Shields colors are...
B50B C9C8 08816 CMP #200 ; ...unchanged with probability of 78% (200:256)
B50D 9007 08817 BCC SKIP201 ;
08818
B50F A000 08819 SKIP199 LDY #$00 ; Prep Shields color {BLACK}
B511 98 08820 SKIP200 TYA ;
B512 D002 08821 BNE SKIP201 ;
08822
B514 A226 08823 LDX #$26 ; Prep Control Panel background color {ORANGE}
08824
B516 8481 08825 SKIP201 STY SHIELDSCOLOR ; Store Shields color
B518 86FB 08826 STX BGRCOLORDLI ; Store Control Panel background color
08827
08828 ;*** Decrement lifetime of our starship's and Zylon photon torpedoes ***********
B51A A202 08829 SKIP202 LDX #2 ; Loop over PLAYER2..4
08830
B51C BD8E0C 08831 LOOP068 LDA PL2SHAPTYPE,X ; Next PLAYER if not PHOTON TORPEDO (shape type 0)
B51F D006 08832 BNE SKIP203 ;
08833
B521 B5EB 08834 LDA PL2LIFE,X ; Next PLAYER if this PLAYER not alive
B523 F002 08835 BEQ SKIP203 ;
08836
B525 D6EB 08837 DEC PL2LIFE,X ; Decrement photon torpedo PLAYER lifetime
08838
B527 CA 08839 SKIP203 DEX ;
B528 10F2 08840 BPL LOOP068 ; Next PLAYER
08841
08842 ;*** Decrement lifetime of explosion *******************************************
B52A A573 08843 LDA EXPLLIFE ; Skip if explosion lifetime expired
B52C F016 08844 BEQ SKIP206 ;
08845
B52E C673 08846 DEC EXPLLIFE ; Decrement explosion lifetime
B530 D004 08847 BNE SKIP204 ; Skip if explosion lifetime still counting
08848
B532 A211 08849 LDX #NUMSPCOBJ.NORM ; Explosion finished,...
B534 8679 08850 STX MAXSPCOBJIND ; ...restore normal number of space objects
08851
B536 C970 08852 SKIP204 CMP #112 ; Skip if explosion lifetime >= 112 game loops
B538 B004 08853 BCS SKIP205 ;
08854
B53A A200 08855 LDX #0 ; HITBADNESS := NO HIT
B53C 868A 08856 STX HITBADNESS ;
08857
B53E C918 08858 SKIP205 CMP #24 ; Skip if explosion lifetime >= 24 game loops (?)
B540 B002 08859 BCS SKIP206 ;
08860
B542 C679 08861 DEC MAXSPCOBJIND ; Decrement number of explosion fragment space objs
08862
08863 ;*** Increment stardate clock **************************************************
B544 C674 08864 SKIP206 DEC CLOCKTIM ; Decrement stardate clock timer
B546 1021 08865 BPL SKIP209 ; Return if timer is still counting
08866
B548 A928 08867 LDA #40 ; Reset stardate clock timer to 40 game loops
B54A 8574 08868 STA CLOCKTIM ;
08869
B54C A204 08870 LDX #4 ; Increment stardate clock of Galactic Chart Panel
B54E FEA309 08871 LOOP069 INC GCSTARDAT,X ;
B551 BDA309 08872 LDA GCSTARDAT,X ;
B554 C9DA 08873 CMP #[CCS.COL3!ROM.9]+1 ;
B556 900D 08874 BCC SKIP208 ;
B558 A9D0 08875 LDA #[CCS.COL3!ROM.0] ;
B55A 9DA309 08876 STA GCSTARDAT,X ;
B55D E003 08877 CPX #3 ;
B55F D001 08878 BNE SKIP207 ;
B561 CA 08879 DEX ;
B562 CA 08880 SKIP207 DEX ;
B563 10E9 08881 BPL LOOP069 ;
08882
08883 ;*** Decrement Zylon unit movement timer ***************************************
B565 C678 08884 SKIP208 DEC ZYLONUNITTIM ; Decrement Zylon unit movement timer
B567 3001 08885 BMI SKIP210 ; If timer < 0 move Zylon units
08886
B569 60 08887 SKIP209 RTS ; Return
08888
08889 ;*** Restore Zylon unit movement timer and decrement score *********************
B56A A931 08890 SKIP210 LDA #49 ; Reset Zylon unit movement timer to 49
B56C 8578 08891 STA ZYLONUNITTIM ;
08892
B56E A5CB 08893 LDA SCORE ; SCORE := SCORE - 1
B570 D002 08894 BNE SKIP211 ;
B572 C6CC 08895 DEC SCORE+1 ;
B574 C6CB 08896 SKIP211 DEC SCORE ;
08897
B576 A664 08898 LDX ISDEMOMODE ; Return if in demo mode
B578 D0EF 08899 BNE SKIP209 ;
08900
08901 ;*** Is starbase surrounded? ***************************************************
B57A 866A 08902 STX L.ISDESTROYED ; Init L.ISDESTROYED with 0 (starbase not destroyed)
B57C BDC908 08903 LOOP070 LDA GCMEMMAP,X ; Loop over all sectors, load sector type
B57F 1019 08904 BPL SKIP212 ; Skip if not a starbase sector
08905
B581 20F1B7 08906 JSR ISSURROUNDED ; Skip if starbase sector not completely surrounded
B584 F014 08907 BEQ SKIP212 ;
08908
08909 ;*** Starbase is surrounded, destroy starbase **********************************
B586 A902 08910 LDA #2 ; Replace starbase sector with 2-Zylon sector
B588 9DC908 08911 STA GCMEMMAP,X ;
B58B 856A 08912 STA L.ISDESTROYED ; Flag destruction of starbase
08913
B58D 38 08914 SEC ; SCORE := SCORE - 18
B58E A5CB 08915 LDA SCORE ;
B590 E912 08916 SBC #18 ;
B592 85CB 08917 STA SCORE ;
B594 A5CC 08918 LDA SCORE+1 ;
B596 E900 08919 SBC #0 ;
B598 85CC 08920 STA SCORE+1 ;
08921
B59A E8 08922 SKIP212 INX ;
B59B 10DF 08923 BPL LOOP070 ; Next sector
08924
08925 ;*** Report starbase destruction ***********************************************
B59D A56A 08926 LDA L.ISDESTROYED ; Skip if no starbase has been destroyed
B59F F00F 08927 BEQ SKIP213 ;
08928
B5A1 2C9709 08929 BIT GCSTATRAD ; Skip notification if Subspace Radio destroyed
B5A4 700A 08930 BVS SKIP213 ;
08931
B5A6 A015 08932 LDY #$15 ; Set title phrase "STARBASE DESTROYED"
B5A8 2023B2 08933 JSR SETTITLE ;
08934
B5AB A218 08935 LDX #$18 ; Play beeper sound pattern MESSAGE FROM STARBASE
B5AD 20A6B3 08936 JSR BEEP ;
08937
08938 ;*** Pick new starbase to be hunted by Zylon units *****************************
B5B0 C69F 08939 SKIP213 DEC HUNTTIM ; Decrement hunting timer
B5B2 3007 08940 BMI SKIP214 ; If timer < 0 decide which starbase to hunt
08941
B5B4 A693 08942 LDX HUNTSECTOR ; Skip if Zylon units already picked starbase to hunt
B5B6 BDC908 08943 LDA GCMEMMAP,X ;
B5B9 301F 08944 BMI SKIP215 ;
08945
B5BB A907 08946 SKIP214 LDA #7 ; Reset hunting timer
B5BD 859F 08947 STA HUNTTIM ;
08948
B5BF A07F 08949 LDY #127 ; Loop over 127(+1) randomly picked sectors
B5C1 AD0AD2 08950 LOOP071 LDA RANDOM ;
B5C4 297F 08951 AND #$7F ;
B5C6 AA 08952 TAX ;
B5C7 BDC908 08953 LDA GCMEMMAP,X ; Skip if starbase sector found
B5CA 300E 08954 BMI SKIP215 ;
B5CC 88 08955 DEY ;
B5CD 10F2 08956 BPL LOOP071 ; Next sector
08957
B5CF A27F 08958 LDX #127 ; Loop over all sectors of the Galactic Chart
B5D1 BDC908 08959 LOOP072 LDA GCMEMMAP,X ;
B5D4 3004 08960 BMI SKIP215 ; Skip if starbase sector found
B5D6 CA 08961 DEX ;
B5D7 10F8 08962 BPL LOOP072 ; Next sector
08963
B5D9 60 08964 RTS ; Return (no starbase sector found)
08965
08966 ;*** Store coordinates of starbase to be hunted ********************************
B5DA 8693 08967 SKIP215 STX HUNTSECTOR ; Store hunted starbase sector column and row
B5DC 8A 08968 TXA ;
B5DD 290F 08969 AND #$0F ;
B5DF 8594 08970 STA HUNTSECTCOLUMN ;
B5E1 8A 08971 TXA ;
B5E2 4A 08972 LSR A ;
B5E3 4A 08973 LSR A ;
B5E4 4A 08974 LSR A ;
B5E5 4A 08975 LSR A ;
B5E6 8595 08976 STA HUNTSECTROW ;
08977
08978 ;*** Move all Zylon units toward hunted starbase *******************************
B5E8 A2FF 08979 LDX #$FF ;
B5EA E8 08980 LOOP073 INX ; Loop over all sectors to move Zylon units
B5EB 1030 08981 BPL SKIP218 ; Jump into loop body below
08982
08983 ;*** Strip marker bits from moved Zylon units **********************************
B5ED A200 08984 LDX #0 ;
B5EF BDC908 08985 LOOP074 LDA GCMEMMAP,X ; Loop over all sectors
B5F2 29DF 08986 AND #$DF ;
B5F4 9DC908 08987 STA GCMEMMAP,X ; Strip marker bit B5 from moved Zylon units
B5F7 E8 08988 INX ;
B5F8 10F5 08989 BPL LOOP074 ; Next sector
08990
08991 ;*** Handle surrounded starbase ************************************************
B5FA 2C9709 08992 BIT GCSTATRAD ; Return if Subspace Radio is destroyed
B5FD 701D 08993 BVS SKIP217 ;
08994
B5FF A200 08995 LDX #0 ; Loop over all sectors
B601 BDC908 08996 LOOP075 LDA GCMEMMAP,X ;
B604 1013 08997 BPL SKIP216 ; Skip if not a starbase sector
B606 20F1B7 08998 JSR ISSURROUNDED ; Skip if starbase not surrounded
B609 F00E 08999 BEQ SKIP216 ;
09000
B60B A963 09001 LDA #99 ; Yes, starbase surrounded...
B60D 8578 09002 STA ZYLONUNITTIM ; ...set Zylon unit movement timer to 99
09003
B60F A013 09004 LDY #$13 ; Set title phrase "STARBASE SURROUNDED"
B611 2023B2 09005 JSR SETTITLE ;
09006
B614 A218 09007 LDX #$18 ; Play beeper sound pattern MESSAGE FROM STARBASE...
B616 4CA6B3 09008 JMP BEEP ; ...and return
09009
B619 E8 09010 SKIP216 INX ;
B61A 10E5 09011 BPL LOOP075 ; Next sector
09012
B61C 60 09013 SKIP217 RTS ; Return
09014
09015 ;*** Move single Zylon unit ****************************************************
B61D BCC908 09016 SKIP218 LDY GCMEMMAP,X ; X contains current sector
B620 C00A 09017 CPY #$0A ; Next sector if it has marker bit B5 set (!)
B622 B0C6 09018 BCS LOOP073 ;
09019
B624 AD0AD2 09020 LDA RANDOM ; Get random number
B627 D9BBBF 09021 CMP MOVEPROBTAB,Y ; Get movement probability
B62A B0BE 09022 BCS LOOP073 ; Next sector if movement probability < random number
09023
B62C E490 09024 CPX CURRSECTOR ; Next sector if this is our starship's sector
B62E F0BA 09025 BEQ LOOP073 ;
09026
09027 ;*** Compute distance to starbase by moving Zylon unit into 9 directions *******
B630 A008 09028 LDY #8 ; Loop over 8(+1) possible directions
B632 18 09029 LOOP076 CLC ;
B633 8A 09030 TXA ;
B634 79C0BF 09031 ADC COMPASSOFFTAB,Y ; Add direction offset to current sector
B637 856A 09032 STA L.NEWSECTOR ; Store new sector
09033
B639 290F 09034 AND #$0F ; Calc distance ("block distance") between...
B63B 38 09035 SEC ; ...starbase sector and tentative new Zylon sector
B63C E594 09036 SBC HUNTSECTCOLUMN ;
B63E B004 09037 BCS SKIP219 ;
B640 49FF 09038 EOR #$FF ;
B642 6901 09039 ADC #1 ;
B644 856B 09040 SKIP219 STA L.ABSDIFFCOLUMN ;
B646 A56A 09041 LDA L.NEWSECTOR ;
B648 4A 09042 LSR A ;
B649 4A 09043 LSR A ;
B64A 4A 09044 LSR A ;
B64B 4A 09045 LSR A ;
B64C 38 09046 SEC ;
B64D E595 09047 SBC HUNTSECTROW ;
B64F B004 09048 BCS SKIP220 ;
B651 49FF 09049 EOR #$FF ;
B653 6901 09050 ADC #1 ;
B655 18 09051 SKIP220 CLC ;
B656 656B 09052 ADC L.ABSDIFFCOLUMN ;
09053
B658 999600 09054 STA NEWZYLONDIST,Y ; Store distance in distance array
B65B 88 09055 DEY ;
B65C 10D4 09056 BPL LOOP076 ; Next direction
09057
09058 ;*** Pick the shortest distance to starbase ************************************
B65E A901 09059 LDA #1 ; Loop over compass rose directions twice to...
B660 856B 09060 STA L.LOOPCNT2 ; ...provoke movement regardless of truncation errors
09061
B662 A007 09062 LOOP077 LDY #7 ;
B664 B99600 09063 LOOP078 LDA NEWZYLONDIST,Y ; Loop over all 7(+1) compass rose directions
B667 C59E 09064 CMP OLDZYLONDIST ;
B669 B024 09065 BCS SKIP222 ; Next direction if new distance > current distance
09066
B66B 18 09067 CLC ; Calc new Galactic Chart sector for Zylon unit
B66C 8A 09068 TXA ;
B66D 79C0BF 09069 ADC COMPASSOFFTAB,Y ;
B670 301D 09070 BMI SKIP222 ; Next direction if new sector outside Galactic Chart
09071
B672 846A 09072 STY L.DIRECTIONIND ; Save compass rose direction index
B674 A8 09073 TAY ;
B675 B9C908 09074 LDA GCMEMMAP,Y ;
B678 D013 09075 BNE SKIP221 ; Next direction if new sector not empty
09076
B67A BDC908 09077 LDA GCMEMMAP,X ; Preload Zylon sector type to be moved
B67D C490 09078 CPY CURRSECTOR ;
B67F F00C 09079 BEQ SKIP221 ; Next direction if sector is our starship's sector
09080
B681 0920 09081 ORA #$20 ; New sector for Zylon unit found!
B683 99C908 09082 STA GCMEMMAP,Y ; Temporarily mark that sector with marker bit B5
B686 A900 09083 LDA #0 ;
B688 9DC908 09084 STA GCMEMMAP,X ; Clear old Zylon unit sector
B68B F00B 09085 BEQ SKIP223 ; Next sector (unconditional branch)
09086
B68D A46A 09087 SKIP221 LDY L.DIRECTIONIND ; Restore compass rose direction index
B68F 88 09088 SKIP222 DEY ; Next compass rose direction
B690 10D2 09089 BPL LOOP078 ;
09090
B692 E69E 09091 INC OLDZYLONDIST ; Increment center distance
B694 C66B 09092 DEC L.LOOPCNT2 ;
B696 10CA 09093 BPL LOOP077 ; Loop over all compass rose directions one more time
09094
B698 4CEAB5 09095 SKIP223 JMP LOOP073 ; Next sector
09096
09097 ; *******************************************************************************
09098 ; * *
09099 ; * ROTATE *
09100 ; * *
09101 ; * Rotate position vector component (coordinate) by fixed angle *
09102 ; * *
09103 ; *******************************************************************************
09104
09105 ; DESCRIPTION
09106 ;
09107 ; This subroutine rotates a position vector component (coordinate) of a space
09108 ; object by a fixed angle around the center of the 3D coordinate system, the
09109 ; location of our starship. This is used in the Front, Aft, and Long-Range Scan
09110 ; views to rotate space objects in and out of the view. Although the code is
09111 ; deceptively short, there is some interesting math involved, so a more detailed
09112 ; discussion is in order.
09113 ;
09114 ; ROTATION MATHEMATICS
09115 ;
09116 ; The game uses a left-handed 3D coordinate system with the positive x-axis
09117 ; pointing to the right, the positive y-axis pointing up, and the positive
09118 ; z-axis pointing into flight direction.
09119 ;
09120 ; A rotation in this coordinate system around the y-axis (horizontal rotation)
09121 ; can be expressed as
09122 ;
09123 ; x' := cos(ry) * x + sin(ry) * z (1a)
09124 ; z' := - sin(ry) * x + cos(ry) * z (1b)
09125 ;
09126 ; where ry is the clockwise rotation angle around the y-axis, x and z are the
09127 ; coordinates before this rotation, and the primed coordinates x' and z' the
09128 ; coordinates after this rotation. The y-coordinate is not changed by this
09129 ; rotation.
09130 ;
09131 ; A rotation in this coordinate system around the x-axis (vertical rotation) can
09132 ; be expressed as
09133 ;
09134 ; z' := cos(rx) * z + sin(rx) * y (2a)
09135 ; y' := - sin(rx) * z + cos(rx) * y (2b)
09136 ;
09137 ; where rx is the clockwise rotation angle around the x-axis, z and y are the
09138 ; coordinates before this rotation, and the primed coordinates z' and y' the
09139 ; coordinates after this rotation. The x-coordinate is not changed by this
09140 ; rotation.
09141 ;
09142 ; SUBROUTINE IMPLEMENTATION OVERVIEW
09143 ;
09144 ; A single call of this subroutine is able to compute one of the four
09145 ; expressions (1a)-(2b). To compute all four expressions to get the new set of
09146 ; coordinates, this subroutine has to be called four times. This is done twice
09147 ; in pairs in GAMELOOP ($A1F3) at $A391 and $A398, and at $A3AE and $A3B5,
09148 ; respectively.
09149 ;
09150 ; The first pair of calls calculates the new x and z coordinates of a space
09151 ; object due to a horizontal (left/right) rotation of our starship around the
09152 ; y-axis following expressions (1a) and (1b).
09153 ;
09154 ; The second pair of calls calculates the new y and z coordinates of the same
09155 ; space object due to a vertical (up/down) rotation of our starship around the
09156 ; x-axis following expressions (2a) and (2b).
09157 ;
09158 ; If you look at the code, you may be wondering how this calculation is actually
09159 ; executed, as there is neither a sin() nor a cos() function call. What you'll
09160 ; actually find implemented, however, are the following calculations:
09161 ;
09162 ; Joystick left Joystick right
09163 ; --------------------- ---------------------
09164 ; x := x + z / 64 (3a) x := x - z / 64 (4a)
09165 ; z := -x / 64 + z (3b) z := x / 64 + z (4b)
09166 ;
09167 ; Joystick down Joystick up
09168 ; --------------------- ---------------------
09169 ; y := y + z / 64 (5a) y := y - z / 64 (6a)
09170 ; z := -y / 64 + z (5b) z := y / 64 + z (6b)
09171 ;
09172 ; CORDIC ALGORITHM
09173 ;
09174 ; When you compare expressions (1a)-(2b) with (3a)-(6b), notice the similarity
09175 ; between the expressions if you substitute
09176 ;
09177 ; sin(ry) -> 1 / 64,
09178 ; cos(ry) -> 1,
09179 ; sin(rx) -> 1 / 64, and
09180 ; cos(rx) -> 1.
09181 ;
09182 ; From sin(ry) = 1 / 64 and sin(rx) = 1 / 64 you can derive that the rotation
09183 ; angles ry and rx by which the space object is rotated per game loop iteration
09184 ; have a constant value of 0.89 degrees, as arcsine(1 / 64) = 0.89 degrees.
09185 ;
09186 ; What about cos(ry) and cos(rx)? The substitution does not match our derived
09187 ; angle exactly, because cos(0.89 degrees) = 0.99988 and is not exactly 1.
09188 ; However, this value is so close to 1 that substituting cos(0.89 degrees) with
09189 ; 1 is a very good approximation, simplifying calculations significantly.
09190 ;
09191 ; Another significant simplification results from the division by 64, because
09192 ; the actual division operation can be replaced with a much faster bit shift
09193 ; operation.
09194 ;
09195 ; This calculation-friendly way of computing rotations is known as the "CORDIC
09196 ; (COordinate Rotation DIgital Computer)" algorithm.
09197 ;
09198 ; MINSKY ROTATION
09199 ;
09200 ; There is one more interesting mathematical subtlety: Did you notice that
09201 ; expressions (1a)-(2b) use a new (primed) pair of variables to store the
09202 ; resulting coordinates, whereas in the implemented expressions (3a)-(6b) the
09203 ; value of the first coordinate of a coordinate pair is overwritten with its new
09204 ; value and this value is used in the subsequent calculation of the second
09205 ; coordinate? For example, when the joystick is pushed left, the first call of
09206 ; this subroutine calculates the new value of x according to expression (3a),
09207 ; overwriting the old value of x. During the second call to calculate z
09208 ; according to expression (3b), the new value of x is used instead of the old
09209 ; one. Is this to save the memory needed to temporarily store the old value of
09210 ; x? Is this a bug? If so, why does the rotation calculation actually work?
09211 ;
09212 ; Have a look at the expression pair (3a) and (3b) (the other expression pairs
09213 ; (4a)-(6b) work in a similar fashion):
09214 ;
09215 ; x := x + z / 64
09216 ; z := -x / 64 + z
09217 ;
09218 ; With the substitution 1 / 64 -> e, we get
09219 ;
09220 ; x := x + e * z
09221 ; z := -e * x + z
09222 ;
09223 ; Note that x is calculated first and then used in the second expression. When
09224 ; using primed coordinates for the resulting coordinates after calculating the
09225 ; two expressions we get
09226 ;
09227 ; x' := x + e * z
09228 ; z' := -e * x' + z = -e * (x + e * z) + z = -e * x + (1 - e^2) * z
09229 ;
09230 ; or in matrix form
09231 ;
09232 ; |x'| := | 1 e | * |x|
09233 ; |z'| |-e (1 - e^2)| |z|
09234 ;
09235 ; Surprisingly, this turns out to be a rotation matrix, because its determinant
09236 ; is (1 * (1 - e^2) - (e * -e)) = 1.
09237 ;
09238 ; (Incidentally, the column vectors of this matrix do not form an orthogonal
09239 ; basis, as their scalar product is 1 * e + (-e * (1 - e^2)) = -e^2.
09240 ; Orthogonality holds for e = 0 only.)
09241 ;
09242 ; This kind of rotation calculation is described by Marvin Minsky in ["AIM 239
09243 ; HAKMEM", Item 149, p. 73, MIT AI Lab, February 1972] and is called "Minsky
09244 ; Rotation".
09245 ;
09246 ; SUBROUTINE IMPLEMENTATION DETAILS
09247 ;
09248 ; To better understand how the implementation of this subroutine works, have
09249 ; again a look at expressions (3a)-(6b). If you rearrange the expressions a
09250 ; little their structure is always of the form
09251 ;
09252 ; TERM1 := TERM1 SIGN TERM2 / 64
09253 ;
09254 ; or shorter
09255 ;
09256 ; TERM1 := TERM1 SIGN TERM3
09257 ;
09258 ; where
09259 ;
09260 ; TERM3 := TERM2 / 64
09261 ; SIGN := + or -
09262 ;
09263 ; and where TERM1 and TERM2 are position vector components (coordinates). In
09264 ; fact, this is all this subroutine actually does: It simply adds TERM2 divided
09265 ; by 64 to TERM1 or subtracts TERM2 divided by 64 from TERM1.
09266 ;
09267 ; When calling this subroutine the correct indices for the appropriate position
09268 ; vector components (coordinates) TERM1 and TERM2 are passed in the Y and X
09269 ; registers, respectively.
09270 ;
09271 ; What about SIGN between TERM1 and TERM3? Have again a look at expressions
09272 ; (3a)-(6b). To compute the two new coordinates after a rotation, the SIGN
09273 ; toggles from plus to minus and vice versa. The SIGN is initialized with
09274 ; JOYSTICKDELTA ($6D) before calling subroutine ROTATE ($B69B) and is toggled
09275 ; inside every call of this subroutine before the addition or subtraction of the
09276 ; terms takes place there. The initial value of SIGN should be positive (+) if
09277 ; the rotation is clockwise (the joystick is pushed right or up) and negative
09278 ; (-) if the rotation is counter-clockwise (the joystick is pushed left or
09279 ; down), respectively. Because SIGN is always toggled inside the subroutine
09280 ; before the addition or subtraction of the terms actually happens there, you
09281 ; have to pass the already toggled value with the first call.
09282 ;
09283 ; NOTE: Unclear still are three instructions starting at address $B6AD. They
09284 ; seem to set the two least significant bits of TERM3 in a random fashion. Could
09285 ; this be some quick hack to avoid messing with exact but potentially lengthy
09286 ; two-complement's arithmetic here?
09287 ;
09288 ; INPUT
09289 ;
09290 ; X = Position vector component index of TERM2. Used values are:
09291 ; $00..$30 -> z-component (z-coordinate) of position vector 0..48
09292 ; $31..$61 -> x-component (x-coordinate) of position vector 0..48
09293 ; $62..$92 -> y-component (y-coordinate) of position vector 0..48
09294 ;
09295 ; Y = Position vector component index of TERM1. Used values are:
09296 ; $00..$30 -> z-component (z-coordinate) of position vector 0..48
09297 ; $31..$61 -> x-component (x-coordinate) of position vector 0..48
09298 ; $62..$92 -> y-component (y-coordinate) of position vector 0..48
09299 ;
09300 ; JOYSTICKDELTA ($6D) = Initial value of SIGN. Used values are:
09301 ; $01 -> (= Positive) Rotate right or up
09302 ; $FF -> (= Negative) Rotate left or down
09303
09304 ; TERM3 is a 24-bit value, represented by 3 bytes as
09305 ; $(sign)(high byte)(low byte)
=006A 09306 L.TERM3LO = $6A ; TERM3 (high byte), where TERM3 := TERM2 / 64
=006B 09307 L.TERM3HI = $6B ; TERM3 (low byte), where TERM3 := TERM2 / 64
=006C 09308 L.TERM3SIGN = $6C ; TERM3 (sign), where TERM3 := TERM2 / 64
09309
B69B BDAD09 09310 ROTATE LDA ZPOSSIGN,X ;
B69E 4901 09311 EOR #$01 ;
B6A0 F002 09312 BEQ SKIP224 ; Skip if sign of TERM2 is positive
B6A2 A9FF 09313 LDA #$FF ;
09314
B6A4 856B 09315 SKIP224 STA L.TERM3HI ; If TERM2 pos. -> TERM3 := $0000xx (= TERM2 / 256)
B6A6 856C 09316 STA L.TERM3SIGN ; If TERM2 neg. -> TERM3 := $FFFFxx (= TERM2 / 256)
B6A8 BD400A 09317 LDA ZPOSHI,X ; where xx := TERM2 (high byte)
B6AB 856A 09318 STA L.TERM3LO ;
09319
B6AD AD0AD2 09320 LDA RANDOM ; (?) Hack to avoid messing with two-complement's
B6B0 09BF 09321 ORA #$BF ; (?) arithmetic? Provides two least significant
B6B2 5DD30A 09322 EOR ZPOSLO,X ; (?) bits B1..0 in TERM3.
09323
B6B5 0A 09324 ASL A ; TERM3 := TERM3 * 4 (= TERM2 / 256 * 4 = TERM2 / 64)
B6B6 266A 09325 ROL L.TERM3LO ;
B6B8 266B 09326 ROL L.TERM3HI ;
B6BA 0A 09327 ASL A ;
B6BB 266A 09328 ROL L.TERM3LO ;
B6BD 266B 09329 ROL L.TERM3HI ;
09330
B6BF A56D 09331 LDA JOYSTICKDELTA ; Toggle SIGN for next call of ROTATE
B6C1 49FF 09332 EOR #$FF ;
B6C3 856D 09333 STA JOYSTICKDELTA ;
B6C5 301A 09334 BMI SKIP225 ; If SIGN negative then subtract, else add TERM3
09335
09336 ;*** Addition ******************************************************************
B6C7 18 09337 CLC ; TERM1 := TERM1 + TERM3
B6C8 B9D30A 09338 LDA ZPOSLO,Y ; (24-bit addition)
B6CB 656A 09339 ADC L.TERM3LO ;
B6CD 99D30A 09340 STA ZPOSLO,Y ;
09341
B6D0 B9400A 09342 LDA ZPOSHI,Y ;
B6D3 656B 09343 ADC L.TERM3HI ;
B6D5 99400A 09344 STA ZPOSHI,Y ;
09345
B6D8 B9AD09 09346 LDA ZPOSSIGN,Y ;
B6DB 656C 09347 ADC L.TERM3SIGN ;
B6DD 99AD09 09348 STA ZPOSSIGN,Y ;
B6E0 60 09349 RTS ;
09350
09351 ;*** Subtraction ***************************************************************
B6E1 38 09352 SKIP225 SEC ; TERM1 := TERM1 - TERM3
B6E2 B9D30A 09353 LDA ZPOSLO,Y ; (24-bit subtraction)
B6E5 E56A 09354 SBC L.TERM3LO ;
B6E7 99D30A 09355 STA ZPOSLO,Y ;
09356
B6EA B9400A 09357 LDA ZPOSHI,Y ;
B6ED E56B 09358 SBC L.TERM3HI ;
B6EF 99400A 09359 STA ZPOSHI,Y ;
09360
B6F2 B9AD09 09361 LDA ZPOSSIGN,Y ;
B6F5 E56C 09362 SBC L.TERM3SIGN ;
B6F7 99AD09 09363 STA ZPOSSIGN,Y ;
B6FA 60 09364 RTS ;
09365
09366 ;*******************************************************************************
09367 ;* *
09368 ;* SCREENCOLUMN *
09369 ;* *
09370 ;* Calculate pixel column number from centered pixel column number *
09371 ;* *
09372 ;*******************************************************************************
09373
09374 ; DESCRIPTION
09375 ;
09376 ; Converts a pixel column number relative to the horizontal screen center to a
09377 ; pixel column number relative to the top-left corner of the screen and stores
09378 ; the result in table PIXELCOLUMN ($0C2A). The passed relative pixel column
09379 ; number is always positive. The sign is picked from the corresponding
09380 ; x-component of the position vector (x-coordinate).
09381 ;
09382 ; If the passed relative pixel column number is offscreen horizontally the
09383 ; calculation is skipped and code execution returns. If the position vector
09384 ; corresponding to this pixel represents a PLAYFIELD space object (star,
09385 ; explosion fragments) a new position vector is initialized before code
09386 ; execution returns. If it represents a PLAYER space object the PLAYER is pushed
09387 ; offscreen before code execution returns.
09388 ;
09389 ; NOTE: The horizontal screen center's pixel column number for PLAYFIELD space
09390 ; objects has a value of 80 = 160 PLAYFIELD pixels / 2. For PLAYER space objects
09391 ; it has a value of 125 Player/Missile (PM) pixels (from left to right: 128 PM
09392 ; pixels to the horizontal screen center - 3 PM pixels relative offset of the
09393 ; PLAYER shape's horizontal center to its left edge = 125 PM pixels).
09394 ;
09395 ; INPUT
09396 ;
09397 ; A = Pixel column number relative to the horizontal screen center, always
09398 ; positive. Used values are:
09399 ; 0..80 -> Regular values, pixel is onscreen
09400 ; $FF -> Pixel is offscreen
09401 ;
09402 ; X = Position vector index. Used values are:
09403 ; 0..4 -> Position vector of a PLAYER space object
09404 ; 5..48 -> Position vector of a PLAYFIELD space object
09405
=006D 09406 L.PIXELCOLUMN = $6D ; Saves relative pixel column number
09407
B6FB C950 09408 SCREENCOLUMN CMP #80 ; If pixel is offscreen (A > 79)...
B6FD B05B 09409 BCS SKIP233 ; ...return via initializing a new position vector
09410
B6FF 856D 09411 STA L.PIXELCOLUMN ; Save relative pixel column number
B701 A950 09412 LDA #80 ; If PLAYFIELD space object -> A := CENTERCOL = 80
B703 E005 09413 CPX #NUMSPCOBJ.PL ; If PLAYER space object -> A := CENTERCOL = 125
B705 B002 09414 BCS SKIP226 ;
B707 A97D 09415 LDA #125 ;
09416
B709 BCDE09 09417 SKIP226 LDY XPOSSIGN,X ; Skip if x-coordinate positive
B70C D009 09418 BNE SKIP227 ;
09419
B70E 38 09420 SEC ; Pixel in left screen half (x-coordinate negative)
B70F E66D 09421 INC L.PIXELCOLUMN ;
B711 E56D 09422 SBC L.PIXELCOLUMN ;
B713 9D2A0C 09423 STA PIXELCOLUMN,X ; Pixel column := CENTERCOL - (rel. pixel column + 1)
B716 60 09424 RTS ; Return
09425
B717 18 09426 SKIP227 CLC ; Pixel in right screen half (x-coordinate positive)
B718 656D 09427 ADC L.PIXELCOLUMN ;
B71A 9D2A0C 09428 STA PIXELCOLUMN,X ; Pixel column := CENTERCOL + relative pixel column
B71D 60 09429 RTS ; Return
09430
09431 ;*******************************************************************************
09432 ;* *
09433 ;* SCREENROW *
09434 ;* *
09435 ;* Calculate pixel row number from centered pixel row number *
09436 ;* *
09437 ;*******************************************************************************
09438
09439 ; Converts a pixel row number relative to the vertical screen center to a pixel
09440 ; row number relative to the top-left corner of the screen and stores the result
09441 ; in table PIXELROWNEW ($0BF9). The passed relative pixel row number is always
09442 ; positive. The sign is picked from the corresponding y-component of the
09443 ; position vector (y-coordinate).
09444 ;
09445 ; If the passed relative pixel row number is offscreen vertically the
09446 ; calculation is skipped and code execution returns. If the position vector
09447 ; corresponding to this pixel represents a PLAYFIELD space object (star,
09448 ; explosion fragments) a new position vector is initialized in subroutine
09449 ; INITPOSVEC ($B764) before code execution returns. If it represents a PLAYER
09450 ; space object the PLAYER is pushed offscreen before code execution returns.
09451 ;
09452 ; NOTE: The vertical screen center's pixel row number for PLAYFIELD space
09453 ; objects has a value of 50 = 100 PLAYFIELD pixels / 2. For PLAYER space objects
09454 ; it has a value of 122 Player/Missile (PM) pixels (from top to bottom: 8 PM
09455 ; pixels to start of Display List + 16 PM pixels to begin of PLAYFIELD + 100 PM
09456 ; pixels to vertical screen center - 2 PM pixels (?) = 122 PM pixels).
09457 ;
09458 ; NOTE: If the position vector corresponding to the pixel represents a PLAYER
09459 ; space object the passed pixel row number is doubled because 1 PLAYFIELD pixel
09460 ; has the same height as 2 PM pixels at single-line resolution.
09461 ;
09462 ; When in Long-Range Scan view the z-coordinate takes the place of the
09463 ; y-coordinate of the Front or Aft view. If the Long-Range Scan is damaged the
09464 ; passed pixel row number is treated randomly as a negative or positive value
09465 ; (mirror effect).
09466 ;
09467 ; INPUT
09468 ;
09469 ; A = Pixel row number relative to the vertical screen center, always
09470 ; positive. Used values are:
09471 ; 0..50 -> Regular values, pixel is onscreen
09472 ; $FF -> Pixel is offscreen
09473 ;
09474 ; X = Position vector index. Used values are:
09475 ; 0..4 -> Position vector of a PLAYER space object
09476 ; 5..48 -> Position vector of a PLAYFIELD space object
09477
=006D 09478 L.PIXELROW = $6D ; Saves relative pixel row number
09479
B71E C932 09480 SCREENROW CMP #50 ; If pixel is offscreen (A > 49)...
B720 B038 09481 BCS SKIP233 ; ...return via initializing a new position vector
09482
B722 856D 09483 STA L.PIXELROW ; Save relative pixel row number
B724 A932 09484 LDA #50 ; If PLAYFIELD space object -> A := CENTERROW = 50
B726 E005 09485 CPX #NUMSPCOBJ.PL ;
B728 B004 09486 BCS SKIP228 ;
B72A 066D 09487 ASL L.PIXELROW ; If PLAYER space object -> Double pixel row number
B72C A97A 09488 LDA #122 ; If PLAYER space object -> A := CENTERROW = 122
09489
B72E 24D0 09490 SKIP228 BIT SHIPVIEW ; Skip if not in Long-Range Scan view
B730 5013 09491 BVC SKIP230 ;
09492
B732 2C9609 09493 BIT GCSTATLRS ; Skip if Long-Range Scan OK
B735 1007 09494 BPL SKIP229 ;
09495
B737 2C0AD2 09496 BIT RANDOM ; Long-Range Scan damaged...
B73A 500E 09497 BVC SKIP231 ; ...branch randomly to pixel row number calculation
B73C 7015 09498 BVS SKIP232 ; ...(mirror effect)
09499
B73E BCAD09 09500 SKIP229 LDY ZPOSSIGN,X ;
B741 D007 09501 BNE SKIP231 ; Skip if z-coordinate pos. (Long-Range Scan view)
B743 F00E 09502 BEQ SKIP232 ; Skip if z-coordinate neg. (Long-Range Scan view)
09503
B745 BC0F0A 09504 SKIP230 LDY YPOSSIGN,X ;
B748 F009 09505 BEQ SKIP232 ; Skip if y-coordinate neg. (Front or Aft view)
09506
B74A 38 09507 SKIP231 SEC ; Pixel in upper screen half (z or y coordinate pos.)
B74B E66D 09508 INC L.PIXELROW ;
B74D E56D 09509 SBC L.PIXELROW ;
B74F 9DF90B 09510 STA PIXELROWNEW,X ; Pixel row := CENTERROW - (rel. pixel row + 1)
B752 60 09511 RTS ; Return
09512
B753 18 09513 SKIP232 CLC ; Pixel in lower screen half (y or z coordinate neg.)
B754 656D 09514 ADC L.PIXELROW ;
B756 9DF90B 09515 STA PIXELROWNEW,X ; Pixel row := CENTERROW + relative pixel row
B759 60 09516 RTS ; Return
09517
B75A E005 09518 SKIP233 CPX #NUMSPCOBJ.PL ; Space object is offscreen. If it is a...
B75C B006 09519 BCS INITPOSVEC ; ...PLAYFIELD space object -> New position vector
B75E A9FB 09520 LDA #251 ; ...PLAYER space object -> Push PLAYER offscreen
B760 9DF90B 09521 STA PIXELROWNEW,X ; Why a value of 251 (?)
B763 60 09522 SKIP234 RTS ; Return
09523
09524 ;*******************************************************************************
09525 ;* *
09526 ;* INITPOSVEC *
09527 ;* *
09528 ;* Initialize position vector of a space object *
09529 ;* *
09530 ;*******************************************************************************
09531
09532 ; DESCRIPTION
09533 ;
09534 ; Initializes the position vector of a space object.
09535 ;
09536 ; This subroutine executes the following steps:
09537 ;
09538 ; (1) Set the pixel row and column number to an offscreen value (= 99).
09539 ;
09540 ; (2) If the position vector represents an explosion fragment space object then
09541 ; return code execution immediately. This avoids generating new explosion
09542 ; fragment space objects. They are separately initialized in subroutine
09543 ; COPYPOSVEC ($ACAF), which is called from subroutine INITEXPL ($AC6B).
09544 ;
09545 ; (3) Assign default values (see below) to the position vector components
09546 ; (coordinates) depending on our starship's view.
09547 ;
09548 ; Code execution continues into subroutine RNDINVXY ($B7BE) where x and y
09549 ; coordinates are inverted randomly.
09550 ;
09551 ; After passing through this and the next subroutine RNDINVXY ($B7BE) the
09552 ; components of a position vector (coordinates) are assigned to one of the
09553 ; following values depending on our starship's view:
09554 ;
09555 ; o FRONT VIEW
09556 ;
09557 ; +------------+---------------------------------------+
09558 ; | Coordinate | Values |
09559 ; +------------+---------------------------------------+
09560 ; | x | -4095..+4095 (-($0***)..+$0***) <KM> |
09561 ; | y | -4095..+4095 (-($0***)..+$0***) <KM> |
09562 ; | z | +3840..+4095 ( +$0F**) <KM> |
09563 ; +------------+---------------------------------------+
09564 ;
09565 ; o AFT VIEW
09566 ;
09567 ; +------------+---------------------------------------+
09568 ; | Coordinate | Values |
09569 ; +------------+---------------------------------------+
09570 ; | x | -3840..+3840 (-($0*00)..+$0*00) <KM> |
09571 ; | y | -3840..+3840 (-($0*00)..+$0*00) <KM> |
09572 ; | z | -3968.. -128 (-($0*80) ) <KM> |
09573 ; +------------+---------------------------------------+
09574 ; Values of x, y, and z coordinates change in increments of 256.
09575 ; Second digit of z-coordinate is -MAX(RNDY,RNDX), where
09576 ; RNDY := RND($00..$0F), RNDX := RND($00..$0F).
09577 ;
09578 ; o LONG-RANGE SCAN VIEW
09579 ;
09580 ; +------------+---------------------------------------+
09581 ; | Coordinate | Values |
09582 ; +------------+---------------------------------------+
09583 ; | x | -65535..+65535 (-($****)..$****) <KM> |
09584 ; | y | -4095..+4095 (-($0***)..$0***) <KM> |
09585 ; | z | -65535..+65535 (-($****)..$****) <KM> |
09586 ; +------------+---------------------------------------+
09587 ;
09588 ; INPUT
09589 ;
09590 ; X = Position vector index. Used values are: 0..48.
09591
=006A 09592 L.MAXRNDXY = $6A ; Saves MAX(new y-coordinate (high byte), ...
09593 ; ...new x-coordinate (high byte))
09594
B764 A963 09595 INITPOSVEC LDA #99 ; Init to offscreen pixel row and column numbers
B766 9DF90B 09596 STA PIXELROWNEW,X ;
B769 9D2A0C 09597 STA PIXELCOLUMN,X ;
09598
B76C E011 09599 CPX #NUMSPCOBJ.NORM ; Return if pos vector is explosion frag space obj
B76E B0F3 09600 BCS SKIP234 ; This avoids creating new explosion frag space objs
09601
B770 AD0AD2 09602 LDA RANDOM ; RNDY := RND($00..$0F)
B773 290F 09603 AND #$0F ;
B775 856A 09604 STA L.MAXRNDXY ; Save RNDY
B777 9DA20A 09605 STA YPOSHI,X ; y-coordinate (high byte) := RNDY
09606
B77A AD0AD2 09607 LDA RANDOM ; RNDX := RND($00..$0F)
B77D 290F 09608 AND #$0F ;
B77F C56A 09609 CMP L.MAXRNDXY ;
B781 9002 09610 BCC SKIP235 ;
B783 856A 09611 STA L.MAXRNDXY ; Save MAX(RNDY,RNDX)
B785 9D710A 09612 SKIP235 STA XPOSHI,X ; x-coordinate (high byte) := RNDX
09613
B788 A90F 09614 LDA #$0F ; z-coordinate (high byte) := $0F
B78A 9D400A 09615 STA ZPOSHI,X ;
09616
B78D A5D0 09617 LDA SHIPVIEW ; z-coordinate (sign) := 1 or 0 (Front or Aft view)
B78F 4901 09618 EOR #$01 ;
B791 2901 09619 AND #$01 ;
B793 9DAD09 09620 STA ZPOSSIGN,X ;
B796 D011 09621 BNE SKIP236 ; Skip if in Front or Long-Range Scan view
09622
09623 ; Aft view only:
B798 9D040B 09624 STA XPOSLO,X ; x-coordinate (low byte) := 0
B79B 9D350B 09625 STA YPOSLO,X ; y-coordinate (low byte) := 0
B79E 38 09626 SEC ; z-coordinate (high byte) := -MAX(RNDY,RNDX)
B79F E56A 09627 SBC L.MAXRNDXY ;
B7A1 9D400A 09628 STA ZPOSHI,X ;
B7A4 A980 09629 LDA #$80 ; z-coordinate (low byte) := $80
B7A6 9DD30A 09630 STA ZPOSLO,X ;
09631
B7A9 24D0 09632 SKIP236 BIT SHIPVIEW ; If not in Long-Range Scan view skip to RNDINVXY
B7AB 5011 09633 BVC RNDINVXY ;
09634
09635 ; Long-Range Scan view only:
B7AD AD0AD2 09636 LDA RANDOM ; x-coordinate (high byte) := RND($00..$FF)
B7B0 9D710A 09637 STA XPOSHI,X ;
B7B3 AD0AD2 09638 LDA RANDOM ; z-coordinate (high byte) := RND($00..$FF)
B7B6 9D400A 09639 STA ZPOSHI,X ;
B7B9 2901 09640 AND #$01 ; Invert z-coordinate randomly
B7BB 9DAD09 09641 STA ZPOSSIGN,X ;
09642
09643 ;*******************************************************************************
09644 ;* *
09645 ;* RNDINVXY *
09646 ;* *
09647 ;* Randomly invert the x and y components of a position vector *
09648 ;* *
09649 ;*******************************************************************************
09650
09651 ; DESCRIPTION
09652 ;
09653 ; Randomly inverts the x and y components of a position vector (x and y
09654 ; coordinates). See also subroutine INITPOSVEC ($B764).
09655 ;
09656 ; INPUT
09657 ;
09658 ; X = Position vector index. Used values are: 0..48.
09659
B7BE AD0AD2 09660 RNDINVXY LDA RANDOM ; Set sign of y-coordinate randomly
B7C1 2901 09661 AND #$01 ;
B7C3 9D0F0A 09662 STA YPOSSIGN,X ;
B7C6 D00F 09663 BNE SKIP237 ; Skip if sign positive
09664
B7C8 38 09665 SEC ; Sign negative -> Calc negative y-coordinate
B7C9 FD350B 09666 SBC YPOSLO,X ; (calculate two's-complement of 16-bit value)
B7CC 9D350B 09667 STA YPOSLO,X ;
B7CF A900 09668 LDA #0 ;
B7D1 FDA20A 09669 SBC YPOSHI,X ;
B7D4 9DA20A 09670 STA YPOSHI,X ;
09671
B7D7 AD0AD2 09672 SKIP237 LDA RANDOM ; Set sign of x-coordinate randomly
B7DA 2901 09673 AND #$01 ;
B7DC 9DDE09 09674 STA XPOSSIGN,X ;
B7DF D00F 09675 BNE SKIP238 ; Skip if sign positive
09676
B7E1 38 09677 SEC ; Sign negative -> Calc negative x-coordinate
B7E2 FD040B 09678 SBC XPOSLO,X ; (calculate two's-complement of 16-bit value)
B7E5 9D040B 09679 STA XPOSLO,X ;
B7E8 A900 09680 LDA #0 ;
B7EA FD710A 09681 SBC XPOSHI,X ;
B7ED 9D710A 09682 STA XPOSHI,X ;
B7F0 60 09683 SKIP238 RTS ; Return
09684
09685 ;*******************************************************************************
09686 ;* *
09687 ;* ISSURROUNDED *
09688 ;* *
09689 ;* Check if a sector is surrounded by Zylon units *
09690 ;* *
09691 ;*******************************************************************************
09692
09693 ; DESCRIPTION
09694 ;
09695 ; Checks if a sector of the Galactic Chart is surrounded by Zylon units in the
09696 ; adjacent NORTH, EAST, SOUTH, and WEST sectors.
09697 ;
09698 ; INPUT
09699 ;
09700 ; X = Sector of Galactic Chart. Used values are: $00..$7F with, for example,
09701 ; $00 -> NORTHWEST corner sector
09702 ; $0F -> NORTHEAST corner sector
09703 ; $70 -> SOUTHWEST corner sector
09704 ; $7F -> SOUTHWEST corner sector
09705 ;
09706 ; OUTPUT
09707 ;
09708 ; A = Returns if the sector is surrounded by Zylon units in the adjacent
09709 ; NORTH, EAST, SOUTH, and WEST sectors.
09710 ; 0 -> Sector is not surrounded
09711 ; > 0 -> Sector is surrounded
09712
B7F1 BDC808 09713 ISSURROUNDED LDA GCMEMMAP-1,X ; Check WEST sector
B7F4 F00D 09714 BEQ SKIP239 ;
B7F6 BDCA08 09715 LDA GCMEMMAP+1,X ; Check EAST sector
B7F9 F008 09716 BEQ SKIP239 ;
B7FB BDB908 09717 LDA GCMEMMAP-16,X ; Check NORTH sector
B7FE F003 09718 BEQ SKIP239 ;
B800 BDD908 09719 LDA GCMEMMAP+16,X ; Check SOUTH sector
B803 60 09720 SKIP239 RTS ; Return
09721
09722 ;*******************************************************************************
09723 ;* *
09724 ;* UPDPANEL *
09725 ;* *
09726 ;* Update Control Panel Display *
09727 ;* *
09728 ;*******************************************************************************
09729
09730 ; DESCRIPTION
09731 ;
09732 ; This subroutine executes the following steps:
09733 ;
09734 ; (1) Accelerate or decelerate our starship, update the VELOCITY readout
09735 ;
09736 ; If the new velocity value is different from the current one either
09737 ; increment or decrement the current velocity value toward the new one.
09738 ;
09739 ; If the Engines are damaged or destroyed (and hyperwarp is not engaged)
09740 ; then store a random value (less or equal than the current velocity) as
09741 ; the current velocity.
09742 ;
09743 ; Display the updated velocity by the VELOCITY readout of the Control Panel
09744 ; Display.
09745 ;
09746 ; (2) Update THETA, PHI, and RANGE readouts.
09747 ;
09748 ; If the Attack Computer is working then display the x, y, and z
09749 ; coordinates of the currently tracked space object as THETA, PHI, and
09750 ; RANGE readout values of the Control Panel Display.
09751 ;
09752 ; (3) Calculate overall energy consumption.
09753 ;
09754 ; Add the overall energy consumption per game loop iteration to the energy
09755 ; counter. This value is given in energy subunits (256 energy subunits = 1
09756 ; energy unit displayed by the 4-digit ENERGY readout of the Console Panel
09757 ; Display). It is the total of the following items:
09758 ;
09759 ; (1) 8 energy subunits if the Shields are up
09760 ;
09761 ; (2) 2 energy subunits if the Attack Computer is on
09762 ;
09763 ; (3) 1 energy subunit of the life support system
09764 ;
09765 ; (4) Our starship's Engines energy drain rate (depending on its velocity)
09766 ;
09767 ; If there is a carryover of the energy counter then decrement the ENERGY
09768 ; readout of the Control Panel Display by one energy unit after code
09769 ; execution has continued into subroutine DECENERGY ($B86F).
09770
09771 ;*** Accelerate or decelerate our starship *************************************
B804 A670 09772 UPDPANEL LDX VELOCITYLO ; Skip if new velocity = current velocity
B806 E471 09773 CPX NEWVELOCITY ;
B808 F008 09774 BEQ SKIP241 ;
09775
B80A 9004 09776 BCC SKIP240 ; In/decrement current velocity toward new velocity
B80C C670 09777 DEC VELOCITYLO ;
B80E B012 09778 BCS SKIP242 ;
B810 E670 09779 SKIP240 INC VELOCITYLO ;
09780
B812 A5C0 09781 SKIP241 LDA WARPSTATE ; Skip if hyperwarp engaged
B814 D00C 09782 BNE SKIP242 ;
09783
B816 2C9309 09784 BIT GCSTATENG ; Skip if Engines are OK
B819 1007 09785 BPL SKIP242 ;
09786
B81B A571 09787 LDA NEWVELOCITY ; Store RND(0..current velocity) to current velocity
B81D 2D0AD2 09788 AND RANDOM ;
B820 8570 09789 STA VELOCITYLO ;
09790
B822 A001 09791 SKIP242 LDY #VELOCD1-PANELTXT-1 ; Update digits of VELOCITY readout
B824 20CDB8 09792 JSR SHOWDIGITS ;
09793
09794 ;*** Display coordinates of tracked space object of Control Panel Display ******
B827 2C9509 09795 BIT GCSTATCOM ; Skip if Attack Computer damaged or destroyed
B82A 3030 09796 BMI SKIP243 ;
09797
B82C A931 09798 LDA #$31 ; Update THETA readout (x-coordinate)
B82E A017 09799 LDY #THETAC1-PANELTXT ;
B830 20A7B8 09800 JSR SHOWCOORD ;
09801
B833 A962 09802 LDA #$62 ; Update PHI readout (y-coordinate)
B835 A01D 09803 LDY #PHIC1-PANELTXT ;
B837 20A7B8 09804 JSR SHOWCOORD ;
09805
B83A A900 09806 LDA #$00 ; Update RANGE readout (z-coordinate)
B83C A023 09807 LDY #RANGEC1-PANELTXT ;
B83E 20A7B8 09808 JSR SHOWCOORD ;
09809
B841 AD6E09 09810 LDA RANGEC1+2 ; Hack to clear RANGE digit 3 when in hyperwarp:
B844 8D6F09 09811 STA RANGEC1+3 ; Copy RANGE digit 2 to digit 3
B847 C90A 09812 CMP #CCS.9+1 ; Skip if digit character > '9' (= 'infinity' char)
B849 B011 09813 BCS SKIP243 ;
09814
B84B AE5C09 09815 LDX TRACKDIGIT ; Get z-coordinate (low byte) of tracked space object
B84E BDD30A 09816 LDA ZPOSLO,X ;
B851 4A 09817 LSR A ; ...divide it by 16...
B852 4A 09818 LSR A ;
B853 4A 09819 LSR A ;
B854 4A 09820 LSR A ;
B855 AA 09821 TAX ;
B856 BDE90E 09822 LDA MAPTOBCD99,X ; ...map value of $00..$0F to BCD value 0..9
B859 8D6F09 09823 STA RANGEC1+3 ; ...and store it to RANGE digit 3
09824
09825 ;*** Calculate overall energy consumption **************************************
B85C 18 09826 SKIP243 CLC ;
B85D A57F 09827 LDA ENERGYCNT ; Load energy counter
B85F 657D 09828 ADC DRAINSHIELDS ; Add energy drain rate of Shields
B861 6580 09829 ADC DRAINENGINES ; Add energy drain rate of our starship's Engines
B863 657E 09830 ADC DRAINATTCOMP ; Add energy drain rate of Attack Computer
B865 6901 09831 ADC #$01 ; Add 1 energy subunit of life support system
B867 C57F 09832 CMP ENERGYCNT ;
B869 857F 09833 STA ENERGYCNT ;
B86B B039 09834 BCS SKIP246 ; Return if no energy counter carryover
09835
B86D A203 09836 LDX #3 ; Will decrement third energy digit
09837
09838 ;*******************************************************************************
09839 ;* *
09840 ;* DECENERGY *
09841 ;* *
09842 ;* Decrease energy *
09843 ;* *
09844 ;*******************************************************************************
09845
09846 ; DESCRIPTION
09847 ;
09848 ; When not in demo mode, subtract energy from the 4-digit ENERGY readout of the
09849 ; Control Panel Display. If crossing a 100-energy-unit boundary during
09850 ; subtraction the score is decremented by one unit. If the energy is zero the
09851 ; game is over.
09852 ;
09853 ; INPUT
09854 ;
09855 ; X = ENERGY readout digit to be decremented. Used values are:
09856 ; 1 -> Subtract 100 units from ENERGY readout
09857 ; 2 -> Subtract 10 units from ENERGY readout
09858 ; 3 -> Subtract 1 unit from ENERGY readout
09859
09860 ;*** Display ENERGY readout ****************************************************
B86F 2464 09861 DECENERGY BIT ISDEMOMODE ; Return if in demo mode
B871 7033 09862 BVS SKIP246 ;
09863
B873 DE5509 09864 DEC ENERGYD1,X ; Decrement energy digit character
B876 BD5509 09865 LDA ENERGYD1,X ;
B879 C980 09866 CMP #CCS.COL2!CCS.0 ;
B87B B029 09867 BCS SKIP246 ; Return if digit character >= '0'
B87D A989 09868 LDA #CCS.COL2!CCS.9 ;
B87F 9D5509 09869 STA ENERGYD1,X ; Store digit character '9'
09870
09871 ;*** Decrement score when crossing a 100-energy-unit boundary while subtracting
B882 E002 09872 CPX #2 ; Skip if no crossing of 100-energy-unit boundary
B884 D008 09873 BNE SKIP245 ;
09874
B886 A5CB 09875 LDA SCORE ; SCORE := SCORE - 1
B888 D002 09876 BNE SKIP244 ;
B88A C6CC 09877 DEC SCORE+1 ;
B88C C6CB 09878 SKIP244 DEC SCORE ;
09879
B88E CA 09880 SKIP245 DEX ;
B88F 10DE 09881 BPL DECENERGY ; Next digit
09882
09883 ;*** Energy is zero, game over *************************************************
B891 A20A 09884 LDX #CCS.SPC ; Clear 4-digit ENERGY readout
B893 8A 09885 TXA ;
B894 A003 09886 LDY #3 ;
B896 995509 09887 LOOP079 STA ENERGYD1,Y ;
B899 88 09888 DEY ;
B89A 10FA 09889 BPL LOOP079 ;
09890
B89C 2045B0 09891 JSR SETVIEW ; Set Front view
09892
B89F A031 09893 LDY #$31 ; Set title phrase "MISSION ABORTED ZERO ENERGY"
B8A1 A204 09894 LDX #$04 ; Set mission bonus offset
B8A3 200AB1 09895 JSR GAMEOVER ; Game over
09896
B8A6 60 09897 SKIP246 RTS ; Return
09898
09899 ;*******************************************************************************
09900 ;* *
09901 ;* SHOWCOORD *
09902 ;* *
09903 ;* Display a position vector component (coordinate) in Control Panel Display *
09904 ;* *
09905 ;*******************************************************************************
09906
09907 ; DESCRIPTION
09908 ;
09909 ; Displays a position vector component (coordinate) by one of the THETA, PHI, or
09910 ; RANGE readouts of the Control Panel Display.
09911 ;
09912 ; Write the sign to the Control Panel Display, then map the high byte of the
09913 ; respective coordinate (x -> THETA, y -> PHI, z -> RANGE) to a BCD-value in
09914 ; 00..99. Code execution continues into subroutine SHOWDIGITS ($B8CD) where the
09915 ; digits are actually stored in the Control Panel Display.
09916 ;
09917 ; NOTE: If the digits of either the THETA or PHI readout are to be displayed and
09918 ; the x or y position vector component (high byte) is $FF then tweak the value
09919 ; to $FE. This avoids accessing table MAPTOBCD99 ($0EE9) with an index of $FF
09920 ; that would return the special value $EA. This value represents the CCS.INF
09921 ; ($0E) and CCS.SPC ($0A) characters (see comments in subroutine INITIALIZE
09922 ; ($B3BA)) that are displayed by the RANGE readout only.
09923 ;
09924 ; INPUT
09925 ;
09926 ; A = Position vector component (coordinate) offset. Used values are:
09927 ; $00 -> z-coordinate
09928 ; $31 -> x-coordinate
09929 ; $62 -> y-coordinate
09930 ;
09931 ; Y = Offset into the Control Panel Display memory map. Used values are:
09932 ; $17 -> First character (sign) of THETA readout (x-coordinate of tracked
09933 ; space object)
09934 ; $1D -> First character (sign) of PHI readout (y-coordinate of tracked
09935 ; space object)
09936 ; $23 -> First character (sign) of RANGE readout (z-coordinate of tracked
09937 ; space object)
09938
=006A 09939 L.SIGNCHAR = $6A ; Saves sign character
09940
B8A7 18 09941 SHOWCOORD CLC ; Add index of tracked space object...
B8A8 6D5C09 09942 ADC TRACKDIGIT ; ...to position vector component offset
B8AB AA 09943 TAX ; Save position vector component index
09944
09945 ;*** Display sign in Control Panel Display *************************************
B8AC A910 09946 LDA #CCS.PLUS ; Save '+' (CCS.PLUS) to sign character
B8AE 856A 09947 STA L.SIGNCHAR ;
09948
B8B0 BDAD09 09949 LDA ZPOSSIGN,X ; Prep sign of coordinate
B8B3 4A 09950 LSR A ;
B8B4 BD400A 09951 LDA ZPOSHI,X ; Prep coordinate (high byte)
B8B7 B004 09952 BCS SKIP247 ; Skip if sign is positive
09953
B8B9 49FF 09954 EOR #$FF ; Invert coordinate (high byte)
B8BB C66A 09955 DEC L.SIGNCHAR ; Change saved sign character to '-' (CCS.MINUS)
09956
B8BD AA 09957 SKIP247 TAX ; Save coordinate (high byte)
B8BE A56A 09958 LDA L.SIGNCHAR ; Store sign character in Control Panel Display
B8C0 994909 09959 STA PANELTXT,Y ;
09960
09961 ;*** Get RANGE digits **********************************************************
B8C3 98 09962 TYA ; Skip if RANGE is to be displayed
B8C4 2910 09963 AND #$10 ;
B8C6 F005 09964 BEQ SHOWDIGITS ;
09965
B8C8 E0FF 09966 CPX #$FF ; If coordinate (high byte) = $FF decrement value
B8CA D001 09967 BNE SHOWDIGITS ; This avoids output of CCS.INFINITY in...
B8CC CA 09968 DEX ; ...THETA and PHI readouts
09969
09970 ;*******************************************************************************
09971 ;* *
09972 ;* SHOWDIGITS *
09973 ;* *
09974 ;* Display a value by a readout of the Control Panel Display *
09975 ;* *
09976 ;*******************************************************************************
09977
09978 ; DESCRIPTION
09979 ;
09980 ; Converts a binary value in $00..$FF to a BCD-value in 0..99 and displays it as
09981 ; a 2-digit number in the Control Panel Display.
09982 ;
09983 ; INPUT
09984 ;
09985 ; X = Value to be displayed as a 2-digit BCD-value. Used values are: $00..$FF.
09986 ;
09987 ; Y = Offset into the Control Panel Display memory map relative to the first
09988 ; character of the Control Panel Display (the 'V' of the VELOCITY
09989 ; readout). Used values are:
09990 ; $01 -> Character before first digit of VELOCITY readout
09991 ; $17 -> First character (sign) of THETA readout (x-coordinate of tracked
09992 ; space object)
09993 ; $1D -> First character (sign) of PHI readout (y-coordinate of tracked
09994 ; space object)
09995 ; $23 -> First character (sign) of RANGE readout (z-coordinate of tracked
09996 ; space object)
09997
B8CD BDE90E 09998 SHOWDIGITS LDA MAPTOBCD99,X ; Map binary value to BCD-value
B8D0 AA 09999 TAX ;
B8D1 290F 10000 AND #$0F ;
B8D3 994B09 10001 STA PANELTXT+2,Y ; Store 'ones' digit in Control Panel Display
B8D6 8A 10002 TXA ;
B8D7 4A 10003 LSR A ;
B8D8 4A 10004 LSR A ;
B8D9 4A 10005 LSR A ;
B8DA 4A 10006 LSR A ;
B8DB 994A09 10007 STA PANELTXT+1,Y ; Store 'tens' digit in Control Panel Display
B8DE 60 10008 RTS ; Return
10009
10010 ;*******************************************************************************
10011 ;* *
10012 ;* G A M E D A T A ( P A R T 2 O F 2 ) *
10013 ;* *
10014 ;*******************************************************************************
10015
10016 ;*** Color register offsets of PLAYER0..4 **************************************
B8DF 00 10017 PLCOLOROFFTAB .BYTE 0 ; PLAYER0
B8E0 01 10018 .BYTE 1 ; PLAYER1
B8E1 02 10019 .BYTE 2 ; PLAYER2
B8E2 03 10020 .BYTE 3 ; PLAYER3
B8E3 07 10021 .BYTE 7 ; PLAYER4
10022
10023 ;*** Shape table 1 (PLAYER2..4) ************************************************
B8E4 00 10024 PLSHAP1TAB .BYTE $00 ; ........
B8E5 18 10025 .BYTE $18 ; ...##...
B8E6 3C 10026 .BYTE $3C ; ..####..
B8E7 7E 10027 .BYTE $7E ; .######.
B8E8 7E 10028 .BYTE $7E ; .######.
B8E9 76 10029 .BYTE $76 ; .###.##.
B8EA F7 10030 .BYTE $F7 ; ####.###
B8EB DF 10031 .BYTE $DF ; ##.#####
B8EC DF 10032 .BYTE $DF ; ##.#####
B8ED FF 10033 .BYTE $FF ; ########
B8EE FF 10034 .BYTE $FF ; ########
B8EF F7 10035 .BYTE $F7 ; ####.###
B8F0 76 10036 .BYTE $76 ; .###.##.
B8F1 7E 10037 .BYTE $7E ; .######.
B8F2 7E 10038 .BYTE $7E ; .######.
B8F3 3C 10039 .BYTE $3C ; ..####..
B8F4 18 10040 .BYTE $18 ; ...##...
B8F5 10 10041 .BYTE $10 ; ...#....
B8F6 38 10042 .BYTE $38 ; ..###...
B8F7 7C 10043 .BYTE $7C ; .#####..
B8F8 7C 10044 .BYTE $7C ; .#####..
B8F9 FE 10045 .BYTE $FE ; #######.
B8FA DE 10046 .BYTE $DE ; ##.####.
B8FB DA 10047 .BYTE $DA ; ##.##.#.
B8FC FA 10048 .BYTE $FA ; #####.#.
B8FD EE 10049 .BYTE $EE ; ###.###.
B8FE EE 10050 .BYTE $EE ; ###.###.
B8FF 7C 10051 .BYTE $7C ; .#####..
B900 7C 10052 .BYTE $7C ; .#####..
B901 38 10053 .BYTE $38 ; ..###...
B902 10 10054 .BYTE $10 ; ...#....
B903 18 10055 .BYTE $18 ; ...##...
B904 3C 10056 .BYTE $3C ; ..####..
B905 3C 10057 .BYTE $3C ; ..####..
B906 7E 10058 .BYTE $7E ; .######.
B907 6E 10059 .BYTE $6E ; .##.###.
B908 7A 10060 .BYTE $7A ; .####.#.
B909 7E 10061 .BYTE $7E ; .######.
B90A 76 10062 .BYTE $76 ; .###.##.
B90B 7E 10063 .BYTE $7E ; .######.
B90C 3C 10064 .BYTE $3C ; ..####..
B90D 3C 10065 .BYTE $3C ; ..####..
B90E 18 10066 .BYTE $18 ; ...##...
B90F 10 10067 .BYTE $10 ; ...#....
B910 38 10068 .BYTE $38 ; ..###...
B911 38 10069 .BYTE $38 ; ..###...
B912 7C 10070 .BYTE $7C ; .#####..
B913 74 10071 .BYTE $74 ; .###.#..
B914 7C 10072 .BYTE $7C ; .#####..
B915 6C 10073 .BYTE $6C ; .##.##..
B916 38 10074 .BYTE $38 ; ..###...
B917 38 10075 .BYTE $38 ; ..###...
B918 10 10076 .BYTE $10 ; ...#....
B919 10 10077 .BYTE $10 ; ...#....
B91A 18 10078 .BYTE $18 ; ...##...
B91B 3C 10079 .BYTE $3C ; ..####..
B91C 2C 10080 .BYTE $2C ; ..#.##..
B91D 3C 10081 .BYTE $3C ; ..####..
B91E 3C 10082 .BYTE $3C ; ..####..
B91F 18 10083 .BYTE $18 ; ...##...
B920 08 10084 .BYTE $08 ; ....#...
B921 10 10085 .BYTE $10 ; ...#....
B922 38 10086 .BYTE $38 ; ..###...
B923 38 10087 .BYTE $38 ; ..###...
B924 28 10088 .BYTE $28 ; ..#.#...
B925 38 10089 .BYTE $38 ; ..###...
B926 10 10090 .BYTE $10 ; ...#....
B927 3C 10091 .BYTE $3C ; ..####..
B928 3C 10092 .BYTE $3C ; ..####..
B929 24 10093 .BYTE $24 ; ..#..#..
B92A 3C 10094 .BYTE $3C ; ..####..
B92B 7E 10095 .BYTE $7E ; .######.
B92C 7E 10096 .BYTE $7E ; .######.
B92D 7E 10097 .BYTE $7E ; .######.
B92E 5A 10098 .BYTE $5A ; .#.##.#.
B92F FF 10099 .BYTE $FF ; ########
B930 FF 10100 .BYTE $FF ; ########
B931 42 10101 .BYTE $42 ; .#....#.
B932 42 10102 .BYTE $42 ; .#....#.
B933 42 10103 .BYTE $42 ; .#....#.
B934 42 10104 .BYTE $42 ; .#....#.
B935 42 10105 .BYTE $42 ; .#....#.
B936 42 10106 .BYTE $42 ; .#....#.
B937 1C 10107 .BYTE $1C ; ...###..
B938 1C 10108 .BYTE $1C ; ...###..
B939 14 10109 .BYTE $14 ; ...#.#..
B93A 3E 10110 .BYTE $3E ; ..#####.
B93B 3E 10111 .BYTE $3E ; ..#####.
B93C 3E 10112 .BYTE $3E ; ..#####.
B93D 2A 10113 .BYTE $2A ; ..#.#.#.
B93E 7F 10114 .BYTE $7F ; .#######
B93F 7F 10115 .BYTE $7F ; .#######
B940 22 10116 .BYTE $22 ; ..#...#.
B941 22 10117 .BYTE $22 ; ..#...#.
B942 22 10118 .BYTE $22 ; ..#...#.
B943 22 10119 .BYTE $22 ; ..#...#.
B944 22 10120 .BYTE $22 ; ..#...#.
B945 18 10121 .BYTE $18 ; ...##...
B946 18 10122 .BYTE $18 ; ...##...
B947 3C 10123 .BYTE $3C ; ..####..
B948 3C 10124 .BYTE $3C ; ..####..
B949 3C 10125 .BYTE $3C ; ..####..
B94A 3C 10126 .BYTE $3C ; ..####..
B94B 7E 10127 .BYTE $7E ; .######.
B94C 24 10128 .BYTE $24 ; ..#..#..
B94D 24 10129 .BYTE $24 ; ..#..#..
B94E 24 10130 .BYTE $24 ; ..#..#..
B94F 24 10131 .BYTE $24 ; ..#..#..
B950 10 10132 .BYTE $10 ; ...#....
B951 10 10133 .BYTE $10 ; ...#....
B952 38 10134 .BYTE $38 ; ..###...
B953 38 10135 .BYTE $38 ; ..###...
B954 38 10136 .BYTE $38 ; ..###...
B955 7C 10137 .BYTE $7C ; .#####..
B956 28 10138 .BYTE $28 ; ..#.#...
B957 28 10139 .BYTE $28 ; ..#.#...
B958 28 10140 .BYTE $28 ; ..#.#...
B959 18 10141 .BYTE $18 ; ...##...
B95A 18 10142 .BYTE $18 ; ...##...
B95B 3C 10143 .BYTE $3C ; ..####..
B95C 18 10144 .BYTE $18 ; ...##...
B95D 18 10145 .BYTE $18 ; ...##...
B95E 10 10146 .BYTE $10 ; ...#....
B95F 10 10147 .BYTE $10 ; ...#....
B960 38 10148 .BYTE $38 ; ..###...
B961 10 10149 .BYTE $10 ; ...#....
B962 18 10150 .BYTE $18 ; ...##...
B963 7E 10151 .BYTE $7E ; .######.
B964 FF 10152 .BYTE $FF ; ########
B965 FF 10153 .BYTE $FF ; ########
B966 FF 10154 .BYTE $FF ; ########
B967 FF 10155 .BYTE $FF ; ########
B968 FF 10156 .BYTE $FF ; ########
B969 E7 10157 .BYTE $E7 ; ###..###
B96A E7 10158 .BYTE $E7 ; ###..###
B96B FF 10159 .BYTE $FF ; ########
B96C FF 10160 .BYTE $FF ; ########
B96D FF 10161 .BYTE $FF ; ########
B96E FF 10162 .BYTE $FF ; ########
B96F FF 10163 .BYTE $FF ; ########
B970 7E 10164 .BYTE $7E ; .######.
B971 7E 10165 .BYTE $7E ; .######.
B972 00 10166 .BYTE $00 ; ........
B973 18 10167 .BYTE $18 ; ...##...
B974 3C 10168 .BYTE $3C ; ..####..
B975 7E 10169 .BYTE $7E ; .######.
B976 FF 10170 .BYTE $FF ; ########
B977 FF 10171 .BYTE $FF ; ########
B978 FF 10172 .BYTE $FF ; ########
B979 E7 10173 .BYTE $E7 ; ###..###
B97A 66 10174 .BYTE $66 ; .##..##.
B97B FF 10175 .BYTE $FF ; ########
B97C FF 10176 .BYTE $FF ; ########
B97D FF 10177 .BYTE $FF ; ########
B97E FF 10178 .BYTE $FF ; ########
B97F 7E 10179 .BYTE $7E ; .######.
B980 7E 10180 .BYTE $7E ; .######.
B981 00 10181 .BYTE $00 ; ........
B982 18 10182 .BYTE $18 ; ...##...
B983 3C 10183 .BYTE $3C ; ..####..
B984 7E 10184 .BYTE $7E ; .######.
B985 FF 10185 .BYTE $FF ; ########
B986 FF 10186 .BYTE $FF ; ########
B987 E7 10187 .BYTE $E7 ; ###..###
B988 66 10188 .BYTE $66 ; .##..##.
B989 FF 10189 .BYTE $FF ; ########
B98A FF 10190 .BYTE $FF ; ########
B98B FF 10191 .BYTE $FF ; ########
B98C FF 10192 .BYTE $FF ; ########
B98D 3C 10193 .BYTE $3C ; ..####..
B98E 18 10194 .BYTE $18 ; ...##...
B98F 3C 10195 .BYTE $3C ; ..####..
B990 FF 10196 .BYTE $FF ; ########
B991 FF 10197 .BYTE $FF ; ########
B992 E7 10198 .BYTE $E7 ; ###..###
B993 66 10199 .BYTE $66 ; .##..##.
B994 FF 10200 .BYTE $FF ; ########
B995 FF 10201 .BYTE $FF ; ########
B996 7E 10202 .BYTE $7E ; .######.
B997 3C 10203 .BYTE $3C ; ..####..
B998 00 10204 .BYTE $00 ; ........
B999 18 10205 .BYTE $18 ; ...##...
B99A 3C 10206 .BYTE $3C ; ..####..
B99B FF 10207 .BYTE $FF ; ########
B99C FF 10208 .BYTE $FF ; ########
B99D FF 10209 .BYTE $FF ; ########
B99E 3C 10210 .BYTE $3C ; ..####..
B99F 18 10211 .BYTE $18 ; ...##...
B9A0 18 10212 .BYTE $18 ; ...##...
B9A1 3C 10213 .BYTE $3C ; ..####..
B9A2 FF 10214 .BYTE $FF ; ########
B9A3 3C 10215 .BYTE $3C ; ..####..
B9A4 18 10216 .BYTE $18 ; ...##...
B9A5 28 10217 .BYTE $28 ; ..#.#...
B9A6 28 10218 .BYTE $28 ; ..#.#...
B9A7 28 10219 .BYTE $28 ; ..#.#...
B9A8 28 10220 .BYTE $28 ; ..#.#...
B9A9 EE 10221 .BYTE $EE ; ###.###.
B9AA 00 10222 .BYTE $00 ; ........
B9AB 00 10223 .BYTE $00 ; ........
B9AC EE 10224 .BYTE $EE ; ###.###.
B9AD 28 10225 .BYTE $28 ; ..#.#...
B9AE 28 10226 .BYTE $28 ; ..#.#...
B9AF 28 10227 .BYTE $28 ; ..#.#...
B9B0 28 10228 .BYTE $28 ; ..#.#...
10229
10230 ;*** Shape table 2 (PLAYER0..1) ************************************************
B9B1 00 10231 PLSHAP2TAB .BYTE $00 ; ........
B9B2 81 10232 .BYTE $81 ; #......#
B9B3 81 10233 .BYTE $81 ; #......#
B9B4 81 10234 .BYTE $81 ; #......#
B9B5 81 10235 .BYTE $81 ; #......#
B9B6 BD 10236 .BYTE $BD ; #.####.#
B9B7 FF 10237 .BYTE $FF ; ########
B9B8 FF 10238 .BYTE $FF ; ########
B9B9 BD 10239 .BYTE $BD ; #.####.#
B9BA 81 10240 .BYTE $81 ; #......#
B9BB 81 10241 .BYTE $81 ; #......#
B9BC 81 10242 .BYTE $81 ; #......#
B9BD 81 10243 .BYTE $81 ; #......#
B9BE 82 10244 .BYTE $82 ; #.....#.
B9BF 82 10245 .BYTE $82 ; #.....#.
B9C0 BA 10246 .BYTE $BA ; #.###.#.
B9C1 FE 10247 .BYTE $FE ; #######.
B9C2 FE 10248 .BYTE $FE ; #######.
B9C3 BA 10249 .BYTE $BA ; #.###.#.
B9C4 82 10250 .BYTE $82 ; #.....#.
B9C5 82 10251 .BYTE $82 ; #.....#.
B9C6 42 10252 .BYTE $42 ; .#....#.
B9C7 5A 10253 .BYTE $5A ; .#.##.#.
B9C8 7E 10254 .BYTE $7E ; .######.
B9C9 7E 10255 .BYTE $7E ; .######.
B9CA 5A 10256 .BYTE $5A ; .#.##.#.
B9CB 42 10257 .BYTE $42 ; .#....#.
B9CC 44 10258 .BYTE $44 ; .#...#..
B9CD 54 10259 .BYTE $54 ; .#.#.#..
B9CE 7C 10260 .BYTE $7C ; .#####..
B9CF 7C 10261 .BYTE $7C ; .#####..
B9D0 54 10262 .BYTE $54 ; .#.#.#..
B9D1 44 10263 .BYTE $44 ; .#...#..
B9D2 24 10264 .BYTE $24 ; ..#..#..
B9D3 3C 10265 .BYTE $3C ; ..####..
B9D4 3C 10266 .BYTE $3C ; ..####..
B9D5 24 10267 .BYTE $24 ; ..#..#..
B9D6 28 10268 .BYTE $28 ; ..#.#...
B9D7 38 10269 .BYTE $38 ; ..###...
B9D8 38 10270 .BYTE $38 ; ..###...
B9D9 28 10271 .BYTE $28 ; ..#.#...
B9DA 18 10272 .BYTE $18 ; ...##...
B9DB 18 10273 .BYTE $18 ; ...##...
B9DC 10 10274 .BYTE $10 ; ...#....
B9DD 10 10275 .BYTE $10 ; ...#....
B9DE E0 10276 .BYTE $E0 ; ###.....
B9DF F8 10277 .BYTE $F8 ; #####...
B9E0 F8 10278 .BYTE $F8 ; #####...
B9E1 FE 10279 .BYTE $FE ; #######.
B9E2 57 10280 .BYTE $57 ; .#.#.###
B9E3 FE 10281 .BYTE $FE ; #######.
B9E4 F8 10282 .BYTE $F8 ; #####...
B9E5 F8 10283 .BYTE $F8 ; #####...
B9E6 C0 10284 .BYTE $C0 ; ##......
B9E7 C0 10285 .BYTE $C0 ; ##......
B9E8 F0 10286 .BYTE $F0 ; ####....
B9E9 C0 10287 .BYTE $C0 ; ##......
B9EA F0 10288 .BYTE $F0 ; ####....
B9EB F0 10289 .BYTE $F0 ; ####....
B9EC FC 10290 .BYTE $FC ; ######..
B9ED BE 10291 .BYTE $BE ; #.#####.
B9EE FC 10292 .BYTE $FC ; ######..
B9EF F0 10293 .BYTE $F0 ; ####....
B9F0 80 10294 .BYTE $80 ; #.......
B9F1 80 10295 .BYTE $80 ; #.......
B9F2 C0 10296 .BYTE $C0 ; ##......
B9F3 C0 10297 .BYTE $C0 ; ##......
B9F4 F0 10298 .BYTE $F0 ; ####....
B9F5 BC 10299 .BYTE $BC ; #.####..
B9F6 F0 10300 .BYTE $F0 ; ####....
B9F7 C0 10301 .BYTE $C0 ; ##......
B9F8 07 10302 .BYTE $07 ; .....###
B9F9 1F 10303 .BYTE $1F ; ...#####
B9FA 1F 10304 .BYTE $1F ; ...#####
B9FB 7F 10305 .BYTE $7F ; .#######
B9FC EA 10306 .BYTE $EA ; ###.#.#.
B9FD 7F 10307 .BYTE $7F ; .#######
B9FE 1F 10308 .BYTE $1F ; ...#####
B9FF 1F 10309 .BYTE $1F ; ...#####
BA00 03 10310 .BYTE $03 ; ......##
BA01 03 10311 .BYTE $03 ; ......##
BA02 0F 10312 .BYTE $0F ; ....####
BA03 03 10313 .BYTE $03 ; ......##
BA04 0F 10314 .BYTE $0F ; ....####
BA05 0F 10315 .BYTE $0F ; ....####
BA06 3F 10316 .BYTE $3F ; ..######
BA07 7D 10317 .BYTE $7D ; .#####.#
BA08 3F 10318 .BYTE $3F ; ..######
BA09 0F 10319 .BYTE $0F ; ....####
BA0A 01 10320 .BYTE $01 ; .......#
BA0B 01 10321 .BYTE $01 ; .......#
BA0C 03 10322 .BYTE $03 ; ......##
BA0D 03 10323 .BYTE $03 ; ......##
BA0E 0F 10324 .BYTE $0F ; ....####
BA0F 3D 10325 .BYTE $3D ; ..####.#
BA10 0F 10326 .BYTE $0F ; ....####
BA11 03 10327 .BYTE $03 ; ......##
BA12 18 10328 .BYTE $18 ; ...##...
BA13 3C 10329 .BYTE $3C ; ..####..
BA14 7E 10330 .BYTE $7E ; .######.
BA15 7E 10331 .BYTE $7E ; .######.
BA16 DB 10332 .BYTE $DB ; ##.##.##
BA17 C3 10333 .BYTE $C3 ; ##....##
BA18 81 10334 .BYTE $81 ; #......#
BA19 81 10335 .BYTE $81 ; #......#
BA1A 81 10336 .BYTE $81 ; #......#
BA1B 10 10337 .BYTE $10 ; ...#....
BA1C 38 10338 .BYTE $38 ; ..###...
BA1D 7C 10339 .BYTE $7C ; .#####..
BA1E 7C 10340 .BYTE $7C ; .#####..
BA1F D6 10341 .BYTE $D6 ; ##.#.##.
BA20 C6 10342 .BYTE $C6 ; ##...##.
BA21 82 10343 .BYTE $82 ; #.....#.
BA22 82 10344 .BYTE $82 ; #.....#.
BA23 18 10345 .BYTE $18 ; ...##...
BA24 3C 10346 .BYTE $3C ; ..####..
BA25 3C 10347 .BYTE $3C ; ..####..
BA26 66 10348 .BYTE $66 ; .##..##.
BA27 66 10349 .BYTE $66 ; .##..##.
BA28 42 10350 .BYTE $42 ; .#....#.
BA29 42 10351 .BYTE $42 ; .#....#.
BA2A 10 10352 .BYTE $10 ; ...#....
BA2B 38 10353 .BYTE $38 ; ..###...
BA2C 38 10354 .BYTE $38 ; ..###...
BA2D 6C 10355 .BYTE $6C ; .##.##..
BA2E 44 10356 .BYTE $44 ; .#...#..
BA2F 44 10357 .BYTE $44 ; .#...#..
BA30 18 10358 .BYTE $18 ; ...##...
BA31 3C 10359 .BYTE $3C ; ..####..
BA32 24 10360 .BYTE $24 ; ..#..#..
BA33 24 10361 .BYTE $24 ; ..#..#..
BA34 10 10362 .BYTE $10 ; ...#....
BA35 38 10363 .BYTE $38 ; ..###...
BA36 28 10364 .BYTE $28 ; ..#.#...
BA37 18 10365 .BYTE $18 ; ...##...
BA38 3C 10366 .BYTE $3C ; ..####..
BA39 7E 10367 .BYTE $7E ; .######.
BA3A FF 10368 .BYTE $FF ; ########
BA3B 18 10369 .BYTE $18 ; ...##...
BA3C 18 10370 .BYTE $18 ; ...##...
BA3D FF 10371 .BYTE $FF ; ########
BA3E 7E 10372 .BYTE $7E ; .######.
BA3F 3C 10373 .BYTE $3C ; ..####..
BA40 18 10374 .BYTE $18 ; ...##...
BA41 10 10375 .BYTE $10 ; ...#....
BA42 38 10376 .BYTE $38 ; ..###...
BA43 7C 10377 .BYTE $7C ; .#####..
BA44 FE 10378 .BYTE $FE ; #######.
BA45 38 10379 .BYTE $38 ; ..###...
BA46 38 10380 .BYTE $38 ; ..###...
BA47 FE 10381 .BYTE $FE ; #######.
BA48 7C 10382 .BYTE $7C ; .#####..
BA49 38 10383 .BYTE $38 ; ..###...
BA4A 10 10384 .BYTE $10 ; ...#....
BA4B 18 10385 .BYTE $18 ; ...##...
BA4C 3C 10386 .BYTE $3C ; ..####..
BA4D 7E 10387 .BYTE $7E ; .######.
BA4E 18 10388 .BYTE $18 ; ...##...
BA4F 7E 10389 .BYTE $7E ; .######.
BA50 3C 10390 .BYTE $3C ; ..####..
BA51 18 10391 .BYTE $18 ; ...##...
BA52 10 10392 .BYTE $10 ; ...#....
BA53 38 10393 .BYTE $38 ; ..###...
BA54 7C 10394 .BYTE $7C ; .#####..
BA55 10 10395 .BYTE $10 ; ...#....
BA56 7C 10396 .BYTE $7C ; .#####..
BA57 38 10397 .BYTE $38 ; ..###...
BA58 10 10398 .BYTE $10 ; ...#....
BA59 18 10399 .BYTE $18 ; ...##...
BA5A 3C 10400 .BYTE $3C ; ..####..
BA5B 18 10401 .BYTE $18 ; ...##...
BA5C 3C 10402 .BYTE $3C ; ..####..
BA5D 18 10403 .BYTE $18 ; ...##...
BA5E 10 10404 .BYTE $10 ; ...#....
BA5F 38 10405 .BYTE $38 ; ..###...
BA60 38 10406 .BYTE $38 ; ..###...
BA61 10 10407 .BYTE $10 ; ...#....
10408
10409 ;*** Display List fragments ****************************************************
10410 ;
10411 ; LOCAL VARIABLES
=1000 10412 PFMEM.C0R0 = PFMEM+0*40 ; Start address of PLAYFIELD row 0
=10C8 10413 PFMEM.C0R5 = PFMEM+5*40 ; Start address of PLAYFIELD row 5
=12A8 10414 PFMEM.C0R17 = PFMEM+17*40 ; Start address of PLAYFIELD row 17
10415
10416 ;*** Display List fragment for Control Panel Display (bottom text window) ******
BA62 8D 10417 DLSTFRAG .BYTE $8D ; GR7 + DLI
BA63 00 10418 .BYTE $00 ; BLK1
BA64 464909 10419 .BYTE $46,<PANELTXT,>PANELTXT ; GR1 @ PANELTXT
BA67 20 10420 .BYTE $20 ; BLK3
BA68 06 10421 .BYTE $06 ; GR1
BA69 00 10422 .BYTE $00 ; BLK1
10423
10424 ;*** Display List fragment for Galactic Chart view *****************************
BA6A 012EA1 10425 DLSTFRAGGC .BYTE $01,<DLSTGC,>DLSTGC ; JMP @ DLSTGC
10426
10427 ;*** Display List fragment for Long-Range Scan view ****************************
BA6D 00 10428 DLSTFRAGLRS .BYTE $00 ; BLK1
BA6E 00 10429 .BYTE $00 ; BLK1
BA6F 46F8A0 10430 .BYTE $46,<LRSHEADER,>LRSHEADER ; GR1 @ LRSHEADER
BA72 4DC810 10431 .BYTE $4D,<PFMEM.C0R5,>PFMEM.C0R5 ; GR7 @ PFMEM.C0R5
10432
10433 ;*** Display List fragment for Aft view ****************************************
BA75 00 10434 DLSTFRAGAFT .BYTE $00 ; BLK1
BA76 00 10435 .BYTE $00 ; BLK1
BA77 4609A1 10436 .BYTE $46,<AFTHEADER,>AFTHEADER ; GR1 @ AFTHEADER
BA7A 4DC810 10437 .BYTE $4D,<PFMEM.C0R5,>PFMEM.C0R5 ; GR7 @ PFMEM.C0R5
10438
10439 ;*** Display List fragment for Front view and Title text line ******************
BA7D 4D0010 10440 DLSTFRAGFRONT .BYTE $4D,<PFMEM.C0R0,>PFMEM.C0R0 ; GR7 @ PFMEM.C0R0
BA80 0D 10441 .BYTE $0D ; GR7
BA81 0D 10442 .BYTE $0D ; GR7
BA82 0D 10443 .BYTE $0D ; GR7
BA83 0D 10444 .BYTE $0D ; GR7
BA84 0D 10445 .BYTE $0D ; GR7
BA85 30 10446 .BYTE $30 ; BLK4
BA86 461F0D 10447 .BYTE $46,<TITLETXT,>TITLETXT ; GR1 @ TITLETXT
BA89 4DA812 10448 .BYTE $4D,<PFMEM.C0R17,>PFMEM.C0R17 ; GR7 @ PFMEM.C0R17
10449
10450 ;*** Display List fragment offsets relative to DLSTFRAG ************************
BA8C 1B 10451 DLSTFRAGOFFTAB .BYTE DLSTFRAGFRONT-DLSTFRAG ; Front view
BA8D 13 10452 .BYTE DLSTFRAGAFT-DLSTFRAG ; Aft view
BA8E 0B 10453 .BYTE DLSTFRAGLRS-DLSTFRAG ; Long-Range Scan view
BA8F 08 10454 .BYTE DLSTFRAGGC-DLSTFRAG ; Galactic Chart view
10455
10456 ;*** 1-byte bit patterns for 4 pixels of same color for PLAYFIELD space objects
BA90 FF 10457 FOURCOLORPIXEL .BYTE $FF ; COLOR3
BA91 FF 10458 .BYTE $FF ; COLOR3
BA92 FF 10459 .BYTE $FF ; COLOR3
BA93 FF 10460 .BYTE $FF ; COLOR3
BA94 AA 10461 .BYTE $AA ; COLOR2
BA95 FF 10462 .BYTE $FF ; COLOR3
BA96 AA 10463 .BYTE $AA ; COLOR2
BA97 FF 10464 .BYTE $FF ; COLOR3
BA98 AA 10465 .BYTE $AA ; COLOR2
BA99 AA 10466 .BYTE $AA ; COLOR2
BA9A AA 10467 .BYTE $AA ; COLOR2
BA9B FF 10468 .BYTE $FF ; COLOR3
BA9C AA 10469 .BYTE $AA ; COLOR2
BA9D AA 10470 .BYTE $AA ; COLOR2
BA9E AA 10471 .BYTE $AA ; COLOR2
BA9F AA 10472 .BYTE $AA ; COLOR2
BAA0 AA 10473 .BYTE $AA ; COLOR2
BAA1 AA 10474 .BYTE $AA ; COLOR2
BAA2 AA 10475 .BYTE $AA ; COLOR2
BAA3 55 10476 .BYTE $55 ; COLOR1
BAA4 55 10477 .BYTE $55 ; COLOR1
BAA5 AA 10478 .BYTE $AA ; COLOR2
BAA6 55 10479 .BYTE $55 ; COLOR1
BAA7 AA 10480 .BYTE $AA ; COLOR2
BAA8 55 10481 .BYTE $55 ; COLOR1
BAA9 55 10482 .BYTE $55 ; COLOR1
BAAA 55 10483 .BYTE $55 ; COLOR1
BAAB AA 10484 .BYTE $AA ; COLOR2
BAAC 55 10485 .BYTE $55 ; COLOR1
BAAD 55 10486 .BYTE $55 ; COLOR1
BAAE 55 10487 .BYTE $55 ; COLOR1
BAAF 55 10488 .BYTE $55 ; COLOR1
10489
10490 ;*** Masks to filter 1 pixel (2 bits) from 4 pixels (1 byte of PLAYFIELD memory)
BAB0 C0 10491 PIXELMASKTAB .BYTE $C0 ; ##......
BAB1 30 10492 .BYTE $30 ; ..##....
BAB2 0C 10493 .BYTE $0C ; ....##..
BAB3 03 10494 .BYTE $03 ; ......##
10495
10496 ;*** Velocity table ************************************************************
BAB4 00 10497 VELOCITYTAB .BYTE 0 ; Speed 0 = 0 <KM/H>
BAB5 01 10498 .BYTE 1 ; Speed 1 = 1 <KM/H>
BAB6 02 10499 .BYTE 2 ; Speed 2 = 2 <KM/H>
BAB7 04 10500 .BYTE 4 ; Speed 3 = 4 <KM/H>
BAB8 08 10501 .BYTE 8 ; Speed 4 = 8 <KM/H>
BAB9 10 10502 .BYTE 16 ; Speed 5 = 16 <KM/H>
BABA 20 10503 .BYTE 32 ; Speed 6 = 32 <KM/H>
BABB 40 10504 .BYTE 64 ; Speed 7 = 64 <KM/H>
BABC 60 10505 .BYTE 96 ; Speed 8 = 96 <KM/H>
BABD 70 10506 .BYTE 112 ; Speed 9 = 112 <KM/H>
10507
10508 ;*** Keyboard code lookup table ************************************************
BABE F2 10509 KEYTAB .BYTE $F2 ; '0' - Speed 0
BABF DF 10510 .BYTE $DF ; '1' - Speed 1
BAC0 DE 10511 .BYTE $DE ; '2' - Speed 2
BAC1 DA 10512 .BYTE $DA ; '3' - Speed 3
BAC2 D8 10513 .BYTE $D8 ; '4' - Speed 4
BAC3 DD 10514 .BYTE $DD ; '5' - Speed 5
BAC4 DB 10515 .BYTE $DB ; '6' - Speed 6
BAC5 F3 10516 .BYTE $F3 ; '7' - Speed 7
BAC6 F5 10517 .BYTE $F5 ; '8' - Speed 8
BAC7 F0 10518 .BYTE $F0 ; '9' - Speed 9
BAC8 F8 10519 .BYTE $F8 ; 'F' - Front view
BAC9 FF 10520 .BYTE $FF ; 'A' - Aft view
BACA C0 10521 .BYTE $C0 ; 'L' - Long-Range Scan view
BACB FD 10522 .BYTE $FD ; 'G' - Galactic Chart view
BACC ED 10523 .BYTE $ED ; 'T' - Tracking on/off
BACD FE 10524 .BYTE $FE ; 'S' - Shields on/off
BACE D2 10525 .BYTE $D2 ; 'C' - Attack Computer on/off
BACF F9 10526 .BYTE $F9 ; 'H' - Hyperwarp
BAD0 E5 10527 .BYTE $E5 ; 'M' - Manual Target Selector
BAD1 CA 10528 .BYTE $CA ; 'P' - Pause
BAD2 E7 10529 .BYTE $E7 ; 'INV' - Abort Mission
10530
10531 ;*** Engines energy drain rates per game loop iteration in energy subunits *****
BAD3 00 10532 DRAINRATETAB .BYTE 0 ;
BAD4 04 10533 .BYTE 4 ;
BAD5 06 10534 .BYTE 6 ;
BAD6 08 10535 .BYTE 8 ;
BAD7 0A 10536 .BYTE 10 ;
BAD8 0C 10537 .BYTE 12 ;
BAD9 0E 10538 .BYTE 14 ;
BADA 1E 10539 .BYTE 30 ;
BADB 2D 10540 .BYTE 45 ;
BADC 3C 10541 .BYTE 60 ;
10542
10543 ;*** Hyperwarp energy depending on distance ************************************
BADD 0A 10544 WARPENERGYTAB .BYTE 10 ; = 100 energy units
BADE 0D 10545 .BYTE 13 ; = 130 energy units
BADF 10 10546 .BYTE 16 ; = 160 energy units
BAE0 14 10547 .BYTE 20 ; = 200 energy units
BAE1 17 10548 .BYTE 23 ; = 230 energy units
BAE2 32 10549 .BYTE 50 ; = 500 energy units
BAE3 46 10550 .BYTE 70 ; = 700 energy units
BAE4 50 10551 .BYTE 80 ; = 800 energy units
BAE5 5A 10552 .BYTE 90 ; = 900 energy units
BAE6 78 10553 .BYTE 120 ; = 1200 energy units
BAE7 7D 10554 .BYTE 125 ; = 1250 energy units
BAE8 82 10555 .BYTE 130 ; = 1300 energy units
BAE9 87 10556 .BYTE 135 ; = 1350 energy units
BAEA 8C 10557 .BYTE 140 ; = 1400 energy units
BAEB 9B 10558 .BYTE 155 ; = 1550 energy units
BAEC AA 10559 .BYTE 170 ; = 1700 energy units
BAED B8 10560 .BYTE 184 ; = 1840 energy units
BAEE C8 10561 .BYTE 200 ; = 2000 energy units
BAEF D0 10562 .BYTE 208 ; = 2080 energy units
BAF0 D8 10563 .BYTE 216 ; = 2160 energy units
BAF1 DF 10564 .BYTE 223 ; = 2230 energy units
BAF2 E8 10565 .BYTE 232 ; = 2320 energy units
BAF3 F1 10566 .BYTE 241 ; = 2410 energy units
BAF4 FA 10567 .BYTE 250 ; = 2500 energy units
10568
10569 ;*** Joystick increments *******************************************************
BAF5 00 10570 STICKINCTAB .BYTE 0 ; Centered
BAF6 01 10571 .BYTE 1 ; Right or up
BAF7 FF 10572 .BYTE -1 ; Left or down
BAF8 00 10573 .BYTE 0 ; Centered
10574
10575 ;*** 3-byte elements to draw cross hairs and Attack Computer Display ***********
10576 ; Byte 1 : Pixel column number of line start
10577 ; Byte 2 : Pixel row number of line start
10578 ; Byte 3 : B7 = 0 -> Draw line to the right
10579 ; B7 = 1 -> Draw line down
10580 ; B6..0 -> Length of line in pixels. Possible values are: 0..127.
10581 ;
10582 ; #
10583 ; # 4
10584 ; # ##############################
10585 ; #1 # # #
10586 ; # # #11 #
10587 ; # # # #
10588 ; # #5 # 8 #6
10589 ; # ############### #
10590 ; # # # #
10591 ; 15 16 # 7 # # 10 #
10592 ; ############### ############### ######## #########
10593 ; # #12 # #
10594 ; # # #13 #
10595 ; # ############### #
10596 ; # # 9 # #
10597 ; # # # #
10598 ; # # #14 #
10599 ; # # 3 # #
10600 ; #2 ##############################
10601 ; #
10602 ; #
10603 ;
10604 ; Front/Aft Cross Hairs Attack Computer Display
10605 ;
10606 ; LOCAL VARIABLES
=0080 10607 DOWN = $80
=0000 10608 RIGHT = $00
10609
BAF9 502887 10610 DRAWLINESTAB .BYTE 80,40,DOWN!7 ; Line 1
BAFC 503687 10611 .BYTE 80,54,DOWN!7 ; Line 2
10612
BAFF 77461E 10613 .BYTE 119,70,RIGHT!30 ; Line 3
BB02 77561E 10614 .BYTE 119,86,RIGHT!30 ; Line 4
BB05 774691 10615 .BYTE 119,70,DOWN!17 ; Line 5
BB08 944691 10616 .BYTE 148,70,DOWN!17 ; Line 6
BB0B 784E06 10617 .BYTE 120,78,RIGHT!6 ; Line 7
BB0E 7E4B0F 10618 .BYTE 126,75,RIGHT!15 ; Line 8
BB11 7E510F 10619 .BYTE 126,81,RIGHT!15 ; Line 9
BB14 8D4E07 10620 .BYTE 141,78,RIGHT!7 ; Line 10
BB17 854784 10621 .BYTE 133,71,DOWN!4 ; Line 11
BB1A 7E4C85 10622 .BYTE 126,76,DOWN!5 ; Line 12
BB1D 8C4C85 10623 .BYTE 140,76,DOWN!5 ; Line 13
BB20 855284 10624 .BYTE 133,82,DOWN!4 ; Line 14
10625
BB23 3E320F 10626 .BYTE 62,50,RIGHT!15 ; Line 15
BB26 54320F 10627 .BYTE 84,50,RIGHT!15 ; Line 16
BB29 FE 10628 .BYTE $FE ; End marker
10629
10630 ;*** 3-byte elements to draw our starship's shape in Long-Range Scan view ******
10631 ;
10632 ; Line 17 18 19 20 21
10633 ; ##
10634 ; ##
10635 ; ## ## ##
10636 ; ## ## ## ## ##
10637 ; ## ## ##
10638
BB2A 4E3582 10639 .BYTE 78,53,DOWN!2 ; Line 17
BB2D 4F3482 10640 .BYTE 79,52,DOWN!2 ; Line 18
BB30 503285 10641 .BYTE 80,50,DOWN!5 ; Line 19
BB33 513482 10642 .BYTE 81,52,DOWN!2 ; Line 20
BB36 523582 10643 .BYTE 82,53,DOWN!2 ; Line 21
BB39 FE 10644 .BYTE $FE ; End marker
10645
10646 ;*** Initial x and y coordinates of a star during hyperwarp ********************
10647 ; The following two tables are used to determine the initial x and y coordinates
10648 ; (high byte) of a star during hyperwarp. An index in 0..3 picks both the x and
10649 ; y coordinate, thus 4 pairs of coordinates are possible:
10650 ;
10651 ; Y +-------+----------------------------+----------------------------+
10652 ; ^ | Index | x-coordinate | y-coordinate |
10653 ; | +-------+----------------------------+----------------------------+
10654 ; |.32. | 0 | +1024..+1279 (+$04**) <KM> | +512..+767 (+$02**) <KM> |
10655 ; |...1 | 1 | +1024..+1279 (+$04**) <KM> | +768..+1023 (+$03**) <KM> |
10656 ; |...0 | 2 | +768..+1023 (+$03**) <KM> | +1024..+1279 (+$04**) <KM> |
10657 ; |.... | 3 | +512..+767 (+$02**) <KM> | +1024..+1279 (+$04**) <KM> |
10658 ; 0----->X +-------+----------------------------+----------------------------+
10659
10660 ;*** Initial x-coordinate (high byte) of star in hyperwarp *********************
BB3A 04 10661 WARPSTARXTAB .BYTE $04 ; +1024..+1279 (+$04**) <KM>
BB3B 04 10662 .BYTE $04 ; +1024..+1279 (+$04**) <KM>
BB3C 03 10663 .BYTE $03 ; +768..+1023 (+$03**) <KM>
BB3D 02 10664 .BYTE $02 ; +512..+767 (+$02**) <KM>
10665
10666 ;*** Initial y-coordinate (high byte) of star in hyperwarp *********************
BB3E 02 10667 WARPSTARYTAB .BYTE $02 ; +512..+767 (+$02**) <KM>
BB3F 03 10668 .BYTE $03 ; +768..+1023 (+$03**) <KM>
BB40 04 10669 .BYTE $04 ; +1024..+1279 (+$04**) <KM>
BB41 04 10670 .BYTE $04 ; +1024..+1279 (+$04**) <KM>
10671
10672 ;*** Text of Control Panel Display (encoded in custom character set) ***********
10673 ; Row 1: "V:00 K:00 E:9999 T:0"
10674 ; Row 2: " O:-00 O:-00 R:-000 "
10675
BB42 12 10676 PANELTXTTAB .BYTE CCS.V
BB43 0B 10677 .BYTE CCS.COLON
BB44 00 10678 .BYTE CCS.0
BB45 00 10679 .BYTE CCS.0
BB46 0A 10680 .BYTE CCS.SPC
BB47 55 10681 .BYTE CCS.COL1!CCS.K
BB48 4B 10682 .BYTE CCS.COL1!CCS.COLON
BB49 40 10683 .BYTE CCS.COL1!CCS.0
BB4A 40 10684 .BYTE CCS.COL1!CCS.0
BB4B 0A 10685 .BYTE CCS.SPC
BB4C 8D 10686 .BYTE CCS.COL2!CCS.E
BB4D 8B 10687 .BYTE CCS.COL2!CCS.COLON
BB4E 89 10688 .BYTE CCS.COL2!CCS.9
BB4F 89 10689 .BYTE CCS.COL2!CCS.9
BB50 89 10690 .BYTE CCS.COL2!CCS.9
BB51 89 10691 .BYTE CCS.COL2!CCS.9
BB52 0A 10692 .BYTE CCS.SPC
BB53 16 10693 .BYTE CCS.T
BB54 0B 10694 .BYTE CCS.COLON
BB55 00 10695 .BYTE CCS.0
10696
BB56 0A 10697 .BYTE CCS.SPC
BB57 14 10698 .BYTE CCS.THETA
BB58 0B 10699 .BYTE CCS.COLON
BB59 0F 10700 .BYTE CCS.MINUS
BB5A 00 10701 .BYTE CCS.0
BB5B 00 10702 .BYTE CCS.0
BB5C 0A 10703 .BYTE CCS.SPC
BB5D 51 10704 .BYTE CCS.COL1!CCS.PHI
BB5E 4B 10705 .BYTE CCS.COL1!CCS.COLON
BB5F 0F 10706 .BYTE CCS.MINUS
BB60 00 10707 .BYTE CCS.0
BB61 00 10708 .BYTE CCS.0
BB62 0A 10709 .BYTE CCS.SPC
BB63 93 10710 .BYTE CCS.COL2!CCS.R
BB64 8B 10711 .BYTE CCS.COL2!CCS.COLON
BB65 0F 10712 .BYTE CCS.MINUS
BB66 00 10713 .BYTE CCS.0
BB67 00 10714 .BYTE CCS.0
BB68 00 10715 .BYTE CCS.0
BB69 0A 10716 .BYTE CCS.SPC
10717
10718 ;*** Text of Galactic Chart Panel Display **************************************
10719 ; Row 1: "WARP ENERGY: 0 "
10720 ; Row 2: "TARGETS: DC:PESCLR "
10721 ; Row 3: "STAR DATE:00.00 "
10722
BB6A 37 10723 .BYTE ROM.W
BB6B 21 10724 .BYTE ROM.A
BB6C 32 10725 .BYTE ROM.R
BB6D 30 10726 .BYTE ROM.P
BB6E 00 10727 .BYTE ROM.SPC
BB6F 25 10728 .BYTE ROM.E
BB70 2E 10729 .BYTE ROM.N
BB71 25 10730 .BYTE ROM.E
BB72 32 10731 .BYTE ROM.R
BB73 27 10732 .BYTE ROM.G
BB74 39 10733 .BYTE ROM.Y
BB75 1A 10734 .BYTE ROM.COLON
BB76 00 10735 .BYTE ROM.SPC
BB77 00 10736 .BYTE ROM.SPC
BB78 00 10737 .BYTE ROM.SPC
BB79 10 10738 .BYTE ROM.0
BB7A 00 10739 .BYTE ROM.SPC
BB7B 00 10740 .BYTE ROM.SPC
BB7C 00 10741 .BYTE ROM.SPC
BB7D 00 10742 .BYTE ROM.SPC
10743
BB7E B4 10744 .BYTE CCS.COL2!ROM.T
BB7F A1 10745 .BYTE CCS.COL2!ROM.A
BB80 B2 10746 .BYTE CCS.COL2!ROM.R
BB81 A7 10747 .BYTE CCS.COL2!ROM.G
BB82 A5 10748 .BYTE CCS.COL2!ROM.E
BB83 B4 10749 .BYTE CCS.COL2!ROM.T
BB84 B3 10750 .BYTE CCS.COL2!ROM.S
BB85 9A 10751 .BYTE CCS.COL2!ROM.COLON
BB86 00 10752 .BYTE ROM.SPC
BB87 00 10753 .BYTE ROM.SPC
BB88 24 10754 .BYTE ROM.D
BB89 23 10755 .BYTE ROM.C
BB8A 1A 10756 .BYTE ROM.COLON
BB8B 30 10757 .BYTE ROM.P
BB8C 25 10758 .BYTE ROM.E
BB8D 33 10759 .BYTE ROM.S
BB8E 23 10760 .BYTE ROM.C
BB8F 2C 10761 .BYTE ROM.L
BB90 32 10762 .BYTE ROM.R
BB91 00 10763 .BYTE ROM.SPC
10764
BB92 F3 10765 .BYTE CCS.COL3!ROM.S
BB93 F4 10766 .BYTE CCS.COL3!ROM.T
BB94 E1 10767 .BYTE CCS.COL3!ROM.A
BB95 F2 10768 .BYTE CCS.COL3!ROM.R
BB96 00 10769 .BYTE ROM.SPC
BB97 E4 10770 .BYTE CCS.COL3!ROM.D
BB98 E1 10771 .BYTE CCS.COL3!ROM.A
BB99 F4 10772 .BYTE CCS.COL3!ROM.T
BB9A E5 10773 .BYTE CCS.COL3!ROM.E
BB9B DA 10774 .BYTE CCS.COL3!ROM.COLON
BB9C D0 10775 .BYTE CCS.COL3!ROM.0
BB9D D0 10776 .BYTE CCS.COL3!ROM.0
BB9E CE 10777 .BYTE CCS.COL3!ROM.DOT
BB9F D0 10778 .BYTE CCS.COL3!ROM.0
BBA0 D0 10779 .BYTE CCS.COL3!ROM.0
BBA1 00 10780 .BYTE ROM.SPC
BBA2 00 10781 .BYTE ROM.SPC
BBA3 00 10782 .BYTE ROM.SPC
BBA4 00 10783 .BYTE ROM.SPC
BBA5 00 10784 .BYTE ROM.SPC
10785
10786 ;*** Galactic Chart sector type table ******************************************
BBA6 CF 10787 SECTORTYPETAB .BYTE $CF ; Starbase
BBA7 04 10788 .BYTE $04 ; 4 Zylon ships
BBA8 03 10789 .BYTE $03 ; 3 Zylon ships
BBA9 02 10790 .BYTE $02 ; 1 or 2 Zylon ships
10791
10792 ;*** Phrase table **************************************************************
10793 ; Phrases consist of phrase tokens. These are bytes that encode words, segments
10794 ; (multiple words that fit into a single line of text), and how they are displayed.
10795 ;
10796 ; LOCAL VARIABLES
=0040 10797 EOP = $40 ; End of phrase
=0080 10798 EOS = $80 ; End of segment
=00C0 10799 LONG = $C0 ; Display title phrase for a long time
10800
10801 ; Title Phrase Offset, Text
BBAA 00 10802 PHRASETAB .BYTE $00 ; (unused)
BBAB 050642 10803 .BYTE $05,$06,$02!EOP ; $01 "ATTACK COMPUTER ON"
BBAE 050643 10804 .BYTE $05,$06,$03!EOP ; $04 "ATTACK COMPUTER OFF"
BBB1 0442 10805 .BYTE $04,$02!EOP ; $07 "SHIELDS ON"
BBB3 0443 10806 .BYTE $04,$03!EOP ; $09 "SHIELDS OFF"
BBB5 060742 10807 .BYTE $06,$07,$02!EOP ; $0B "COMPUTER TRACKING ON"
BBB8 0743 10808 .BYTE $07,$03!EOP ; $0E "TRACKING OFF"
BBBA 48 10809 .BYTE $08!EOP ; $10 "WHATS WRONG?"
BBBB 094A 10810 .BYTE $09,$0A!EOP ; $11 "HYPERWARP ENGAGED"
BBBD 0BCD 10811 .BYTE $0B,$0D!LONG ; $13 "STARBASE SURROUNDED"
BBBF 0BCC 10812 .BYTE $0B,$0C!LONG ; $15 "STARBASE DESTROYED"
BBC1 094E 10813 .BYTE $09,$0E!EOP ; $17 "HYPERWARP ABORTED"
BBC3 094F 10814 .BYTE $09,$0F!EOP ; $19 "HYPERWARP COMPLETE"
BBC5 D0 10815 .BYTE $10!LONG ; $1B "HYPERSPACE"
BBC6 1192 10816 .BYTE $11,$12!EOS ; $1C "ORBIT ESTABLISHED"
BBC8 56 10817 .BYTE $16!EOP ; $1E "STANDBY"
BBC9 134E 10818 .BYTE $13,$0E!EOP ; $1F "DOCKING ABORTED"
BBCB 154F 10819 .BYTE $15,$0F!EOP ; $21 "TRANSFER COMPLETE"
BBCD B8 10820 .BYTE $38!EOS ; $23 " "
BBCE 97 10821 .BYTE $17!EOS ; $24 "STAR FLEET TO"
BBCF 99 10822 .BYTE $19!EOS ; $25 "ALL UNITS"
BBD0 98 10823 .BYTE $18!EOS ; $26 "STAR CRUISER 7"
BBD1 8C 10824 .BYTE $0C!EOS ; $27 "DESTROYED"
BBD2 9D 10825 .BYTE $1D!EOS ; $28 "BY ZYLON FIRE"
BBD3 1E9F 10826 .BYTE $1E,$1F!EOS ; $29 "POSTHUMOUS RANK IS:"
BBD5 FD 10827 .BYTE $FD ; $2B "<PLACEHOLDER FOR RANK>"
BBD6 25FC 10828 .BYTE $25,$FC ; $2C "CLASS <PLACEHOLDER FOR CLASS>"
BBD8 78 10829 .BYTE $38!EOP ; $2E " "
BBD9 9B 10830 .BYTE $1B!EOS ; $2F "STAR RAIDERS"
BBDA 60 10831 .BYTE $20!EOP ; $30 "COPYRIGHT ATARI 1979"
BBDB B8 10832 .BYTE $38!EOS ; $31 " "
BBDC 97 10833 .BYTE $17!EOS ; $32 "STAR FLEET TO"
BBDD 98 10834 .BYTE $18!EOS ; $33 "STAR CRUISER 7"
BBDE 1A8E 10835 .BYTE $1A,$0E!EOS ; $34 "MISSION ABORTED"
BBE0 1C94 10836 .BYTE $1C,$14!EOS ; $36 "ZERO ENERGY"
BBE2 249F 10837 .BYTE $24,$1F!EOS ; $38 "NEW RANK IS"
BBE4 FD 10838 .BYTE $FD ; $3A "<PLACEHOLDER FOR RANK>"
BBE5 25FC 10839 .BYTE $25,$FC ; $3B "CLASS <PLACEHOLDER FOR CLASS>"
BBE7 A7 10840 .BYTE $27!EOS ; $3D "REPORT TO BASE"
BBE8 68 10841 .BYTE $28!EOP ; $3E "FOR TRAINING"
BBE9 B8 10842 .BYTE $38!EOS ; $3F " "
BBEA 97 10843 .BYTE $17!EOS ; $40 "STAR FLEET TO"
BBEB 98 10844 .BYTE $18!EOS ; $41 "STAR CRUISER 7"
BBEC 1A8F 10845 .BYTE $1A,$0F!EOS ; $42 "MISSION COMPLETE"
BBEE 249F 10846 .BYTE $24,$1F!EOS ; $44 "NEW RANK IS:"
BBF0 FD 10847 .BYTE $FD ; $46 "<PLACEHOLDER FOR RANK>"
BBF1 25FC 10848 .BYTE $25,$FC ; $47 "CLASS <PLACEHOLDER FOR CLASS>"
BBF3 66 10849 .BYTE $26!EOP ; $49 "CONGRATULATIONS"
BBF4 2C5A 10850 .BYTE $2C,$1A!EOP ; $4A "NOVICE MISSION"
BBF6 2E5A 10851 .BYTE $2E,$1A!EOP ; $4C "PILOT MISSION"
BBF8 315A 10852 .BYTE $31,$1A!EOP ; $4E "WARRIOR MISSION"
BBFA 335A 10853 .BYTE $33,$1A!EOP ; $50 "COMMANDER MISSION"
BBFC B8 10854 .BYTE $38!EOS ; $52 " "
BBFD 3476 10855 .BYTE $34,$36!EOP ; $53 "DAMAGE CONTROL"
BBFF 37B5 10856 .BYTE $37,$35!EOS ; $55 "PHOTONS DAMAGED"
BC01 78 10857 .BYTE $38!EOP ; $57 " "
BC02 378C 10858 .BYTE $37,$0C!EOS ; $58 "PHOTONS DESTROYED"
BC04 78 10859 .BYTE $38!EOP ; $5A " "
BC05 23B5 10860 .BYTE $23,$35!EOS ; $5B "ENGINES DAMAGED"
BC07 78 10861 .BYTE $38!EOP ; $5D " "
BC08 238C 10862 .BYTE $23,$0C!EOS ; $5E "ENGINES DESTROYED"
BC0A 78 10863 .BYTE $38!EOP ; $60 " "
BC0B 04B5 10864 .BYTE $04,$35!EOS ; $61 "SHIELDS DAMAGED"
BC0D 78 10865 .BYTE $38!EOP ; $63 " "
BC0E 048C 10866 .BYTE $04,$0C!EOS ; $64 "SHIELDS DESTROYED"
BC10 78 10867 .BYTE $38!EOP ; $66 " "
BC11 06B5 10868 .BYTE $06,$35!EOS ; $67 "COMPUTER DAMAGED"
BC13 78 10869 .BYTE $38!EOP ; $69 " "
BC14 068C 10870 .BYTE $06,$0C!EOS ; $6A "COMPUTER DESTROYED"
BC16 78 10871 .BYTE $38!EOP ; $6C " "
BC17 A2 10872 .BYTE $22!EOS ; $6D "SECTOR SCAN"
BC18 75 10873 .BYTE $35!EOP ; $6E "DAMAGED"
BC19 A2 10874 .BYTE $22!EOS ; $6F "SECTOR SCAN"
BC1A 4C 10875 .BYTE $0C!EOP ; $70 "DESTROYED"
BC1B A1 10876 .BYTE $21!EOS ; $71 "SUB-SPACE RADIO"
BC1C 75 10877 .BYTE $35!EOP ; $72 "DAMAGED"
BC1D A1 10878 .BYTE $21!EOS ; $73 "SUB-SPACE RADIO"
BC1E 4C 10879 .BYTE $0C!EOP ; $74 "DESTROYED"
BC1F C1 10880 .BYTE $01!LONG ; $75 "RED ALERT"
BC20 B8 10881 .BYTE $38!EOS ; $76 " "
BC21 97 10882 .BYTE $17!EOS ; $77 "STAR FLEET TO"
BC22 98 10883 .BYTE $18!EOS ; $78 "STAR CRUISER 7"
BC23 1A8E 10884 .BYTE $1A,$0E!EOS ; $79 "MISSION ABORTED"
BC25 249F 10885 .BYTE $24,$1F!EOS ; $7B "NEW RANK IS:"
BC27 FD 10886 .BYTE $FD ; $7D "<PLACEHOLDER FOR RANK>"
BC28 25FC 10887 .BYTE $25,$FC ; $7E "CLASS <PLACEHOLDER FOR CLASS>"
BC2A 66 10888 .BYTE $26!EOP ; $80 "CONGRATULATIONS"
10889
10890 ;*** Word table ****************************************************************
10891 ; Bit B7 of the first byte of a word is the end-of-word marker of the preceding
10892 ; word
10893 ;
10894 ; LOCAL VARIABLES
=0080 10895 EOW = $80 ; End of word
10896
BC2B A0202020 10897 WORDTAB .BYTE EOW!$20," RED ALERT" ; Word $01
BC2F 20524544
BC33 20414C45
BC37 5254
BC39 CF4E 10898 .BYTE EOW!'O,"N" ; Word $02
BC3B CF4646 10899 .BYTE EOW!'O,"FF" ; Word $03
BC3E D3484945 10900 .BYTE EOW!'S,"HIELDS" ; Word $04
BC42 4C4453
BC45 C1545441 10901 .BYTE EOW!'A,"TTACK" ; Word $05
BC49 434B
BC4B C34F4D50 10902 .BYTE EOW!'C,"OMPUTER" ; Word $06
BC4F 55544552
BC53 D4524143 10903 .BYTE EOW!'T,"RACKING" ; Word $07
BC57 4B494E47
BC5B D7484154 10904 .BYTE EOW!'W,"HATS WRONG?" ; Word $08
BC5F 53205752
BC63 4F4E473F
BC67 C8595045 10905 .BYTE EOW!'H,"YPERWARP" ; Word $09
BC6B 52574152
BC6F 50
BC70 C54E4741 10906 .BYTE EOW!'E,"NGAGED" ; Word $0A
BC74 474544
BC77 D3544152 10907 .BYTE EOW!'S,"TARBASE" ; Word $0B
BC7B 42415345
BC7F C4455354 10908 .BYTE EOW!'D,"ESTROYED" ; Word $0C
BC83 524F5945
BC87 44
BC88 D3555252 10909 .BYTE EOW!'S,"URROUNDED" ; Word $0D
BC8C 4F554E44
BC90 4544
BC92 C1424F52 10910 .BYTE EOW!'A,"BORTED" ; Word $0E
BC96 544544
BC99 C34F4D50 10911 .BYTE EOW!'C,"OMPLETE" ; Word $0F
BC9D 4C455445
BCA1 C8595045 10912 .BYTE EOW!'H,"YPERSPACE" ; Word $10
BCA5 52535041
BCA9 4345
BCAB CF524249 10913 .BYTE EOW!'O,"RBIT" ; Word $11
BCAF 54
BCB0 C5535441 10914 .BYTE EOW!'E,"STABLISHED" ; Word $12
BCB4 424C4953
BCB8 484544
BCBB C44F434B 10915 .BYTE EOW!'D,"OCKING" ; Word $13
BCBF 494E47
BCC2 C54E4552 10916 .BYTE EOW!'E,"NERGY" ; Word $14
BCC6 4759
BCC8 D452414E 10917 .BYTE EOW!'T,"RANSFER" ; Word $15
BCCC 53464552
BCD0 D354414E 10918 .BYTE EOW!'S,"TANDBY" ; Word $16
BCD4 444259
BCD7 D3544152 10919 .BYTE EOW!'S,"TAR FLEET TO" ; Word $17
BCDB 20464C45
BCDF 45542054
BCE3 4F
BCE4 D3544152 10920 .BYTE EOW!'S,"TAR CRUISER 7" ; Word $18
BCE8 20435255
BCEC 49534552
BCF0 2037
BCF2 C14C4C20 10921 .BYTE EOW!'A,"LL UNITS" ; Word $19
BCF6 554E4954
BCFA 53
BCFB CD495353 10922 .BYTE EOW!'M,"ISSION" ; Word $1A
BCFF 494F4E
BD02 A0202020 10923 .BYTE EOW!$20," STAR RAIDERS" ; Word $1B
BD06 53544152
BD0A 20524149
BD0E 44455253
BD12 DA45524F 10924 .BYTE EOW!'Z,"ERO" ; Word $1C
BD16 C259205A 10925 .BYTE EOW!'B,"Y ZYLON FIRE" ; Word $1D
BD1A 594C4F4E
BD1E 20464952
BD22 45
BD23 D04F5354 10926 .BYTE EOW!'P,"OSTHUMOUS" ; Word $1E
BD27 48554D4F
BD2B 5553
BD2D D2414E4B 10927 .BYTE EOW!'R,"ANK IS:" ; Word $1F
BD31 2049533A
BD35 C34F5059 10928 .BYTE EOW!'C,"OPYRIGHT ATARI 1979" ; Word $20
BD39 52494748
BD3D 54204154
BD41 41524920
BD45 31393739
BD49 D355422D 10929 .BYTE EOW!'S,"UB-SPACE RADIO" ; Word $21
BD4D 53504143
BD51 45205241
BD55 44494F
BD58 D3454354 10930 .BYTE EOW!'S,"ECTOR SCAN" ; Word $22
BD5C 4F522053
BD60 43414E
BD63 C54E4749 10931 .BYTE EOW!'E,"NGINES" ; Word $23
BD67 4E4553
BD6A CE4557 10932 .BYTE EOW!'N,"EW" ; Word $24
BD6D C34C4153 10933 .BYTE EOW!'C,"LASS" ; Word $25
BD71 53
BD72 C34F4E47 10934 .BYTE EOW!'C,"ONGRATULATIONS" ; Word $26
BD76 52415455
BD7A 4C415449
BD7E 4F4E53
BD81 D245504F 10935 .BYTE EOW!'R,"EPORT TO BASE" ; Word $27
BD85 52542054
BD89 4F204241
BD8D 5345
BD8F C64F5220 10936 .BYTE EOW!'F,"OR TRAINING" ; Word $28
BD93 54524149
BD97 4E494E47
BD9B C7414C41 10937 .BYTE EOW!'G,"ALACTIC COOK" ; Word $29
BD9F 43544943
BDA3 20434F4F
BDA7 4B
BDA8 C7415242 10938 .BYTE EOW!'G,"ARBAGE SCOW CAPTAIN" ; Word $2A
BDAC 41474520
BDB0 53434F57
BDB4 20434150
BDB8 5441494E
BDBC D24F4F4B 10939 .BYTE EOW!'R,"OOKIE" ; Word $2B
BDC0 4945
BDC2 CE4F5649 10940 .BYTE EOW!'N,"OVICE" ; Word $2C
BDC6 4345
BDC8 C54E5349 10941 .BYTE EOW!'E,"NSIGN" ; Word $2D
BDCC 474E
BDCE D0494C4F 10942 .BYTE EOW!'P,"ILOT" ; Word $2E
BDD2 54
BDD3 C14345 10943 .BYTE EOW!'A,"CE" ; Word $2F
BDD6 CC494555 10944 .BYTE EOW!'L,"IEUTENANT" ; Word $30
BDDA 54454E41
BDDE 4E54
BDE0 D7415252 10945 .BYTE EOW!'W,"ARRIOR" ; Word $31
BDE4 494F52
BDE7 C3415054 10946 .BYTE EOW!'C,"APTAIN" ; Word $32
BDEB 41494E
BDEE C34F4D4D 10947 .BYTE EOW!'C,"OMMANDER" ; Word $33
BDF2 414E4445
BDF6 52
BDF7 C4414D41 10948 .BYTE EOW!'D,"AMAGE" ; Word $34
BDFB 4745
BDFD C4414D41 10949 .BYTE EOW!'D,"AMAGED" ; Word $35
BE01 474544
BE04 C34F4E54 10950 .BYTE EOW!'C,"ONTROL" ; Word $36
BE08 524F4C
BE0B D0484F54 10951 .BYTE EOW!'P,"HOTONS" ; Word $37
BE0F 4F4E53
BE12 A0 10952 .BYTE EOW!$20 ; Word $38
BE13 D3544152 10953 .BYTE EOW!'S,"TAR COMMANDER" ; Word $39
BE17 20434F4D
BE1B 4D414E44
BE1F 4552
BE21 80 10954 .BYTE EOW!$00 ;
10955
10956 ;*** View modes ****************************************************************
BE22 00 10957 VIEWMODETAB .BYTE $00 ; Front view
BE23 01 10958 .BYTE $01 ; Aft view
BE24 40 10959 .BYTE $40 ; Long-Range Scan view
BE25 80 10960 .BYTE $80 ; Galactic Chart view
10961
10962 ;*** Title phrase offsets of "TRACKING OFF", "SHIELDS OFF", "COMPUTER OFF" *****
BE26 0E 10963 MSGOFFTAB .BYTE $0E ; "TRACKING OFF"
BE27 09 10964 .BYTE $09 ; "SHIELDS OFF"
BE28 04 10965 .BYTE $04 ; "COMPUTER OFF"
10966
10967 ;*** Masks to test if Tracking Computer, Shields, or Attack Computer are on ****
BE29 FF 10968 MSGBITTAB .BYTE $FF ; Mask Tracking Computer
BE2A 08 10969 .BYTE $08 ; Mask Shields
BE2B 02 10970 .BYTE $02 ; Mask Attack Computer
10971
10972 ;*** Title phrase offsets of "COMPUTER TRACKING ON", "SHIELDS ON", "COMPUTER ON"
BE2C 0B 10973 MSGONTAB .BYTE $0B ; "COMPUTER TRACKING ON"
BE2D 07 10974 .BYTE $07 ; "SHIELDS ON"
BE2E 01 10975 .BYTE $01 ; "COMPUTER ON"
10976
10977 ;*** The following two tables encode the PLAYER shapes *************************
10978 ;
10979 ; PHOTON TORPEDO (shape type 0, data in shape table PLSHAP1TAB)
10980 ; Numbers at top indicate the shape table offset of the first and last shape row
10981 ;
10982 ; $01..$10 $11..$1E $1F..$2A $2B..$34 $35..$3C $3D..$42 $75..$76 $7A..$7B
10983 ; ...##... ...#.... ...##... ...#.... ...#.... ...#.... ...##... ...#....
10984 ; ..####.. ..###... ..####.. ..###... ...##... ..###... ...##... ...#....
10985 ; .######. .#####.. ..####.. ..###... ..####.. ..###...
10986 ; .######. .#####.. .######. .#####.. ..#.##.. ..#.#...
10987 ; .###.##. #######. .##.###. .###.#.. ..####.. ..###...
10988 ; ####.### ##.####. .####.#. .#####.. ..####.. ...#....
10989 ; ##.##### ##.##.#. .######. .##.##.. ...##...
10990 ; ##.##### #####.#. .###.##. ..###... ....#...
10991 ; ######## ###.###. .######. ..###...
10992 ; ######## ###.###. ..####.. ...#....
10993 ; ####.### .#####.. ..####..
10994 ; .###.##. .#####.. ...##...
10995 ; .######. ..###...
10996 ; .######. ...#....
10997 ; ..####..
10998 ; ...##...
10999 ;
11000 ; ZYLON FIGHTER (shape type 1, data in shape table PLSHAP2TAB)
11001 ; Numbers at top indicate the shape table offset of the first and last shape row
11002 ;
11003 ; $01..$0C $0D..$14 $15..$1A $1B..$20 $21..$24 $25..$28 $29..$2A $2B..$2C
11004 ; #......# #.....#. .#....#. .#...#.. ..#..#.. ..#.#... ...##... ...#....
11005 ; #......# #.....#. .#.##.#. .#.#.#.. ..####.. ..###... ...##... ...#....
11006 ; #......# #.###.#. .######. .#####.. ..####.. ..###...
11007 ; #......# #######. .######. .#####.. ..#..#.. ..#.#...
11008 ; #.####.# #######. .#.##.#. .#.#.#..
11009 ; ######## #.###.#. .#....#. .#...#..
11010 ; ######## #.....#.
11011 ; #.####.# #.....#.
11012 ; #......#
11013 ; #......#
11014 ; #......#
11015 ; #......#
11016 ;
11017 ; STARBASE RIGHT (shape type 2, data in shape table PLSHAP2TAB)
11018 ; Numbers at top indicate the shape table offset of the first and last shape row
11019 ;
11020 ; $2D..$36 $38..$40 $41..$46 $36..$38 $36 $00 $00 $00
11021 ; ###..... ##...... ##...... ##...... ##...... ........ ........ ........
11022 ; #####... ####.... ##...... ####....
11023 ; #####... ####.... ####.... ##......
11024 ; #######. ######.. #.####..
11025 ; #.#.### #.#####. ####....
11026 ; #######. ######.. ##......
11027 ; #####... ####....
11028 ; #####... #.......
11029 ; ##...... #.......
11030 ; ##......
11031 ;
11032 ; STARBASE CENTER (shape type 3, data in shape table PLSHAP1TAB)
11033 ; Numbers at top indicate the shape table offset of the first and last shape row
11034 ;
11035 ; $7E..$8D $8E..$9C $9D..$A9 $AA..$B3 $B4..$BB $BC..$C0 $7B..$7D $7A..$7B
11036 ; ...##... ........ ........ ...##... ........ ...##... ...#.... ...#....
11037 ; .######. ...##... ...##... ..####.. ...##... ..####.. ..###... ...#....
11038 ; ######## ..####.. ..####.. ######## ..####.. ######## ...#....
11039 ; ######## .######. .######. ######## ######## ..####..
11040 ; ######## ######## ######## ###..### ######## ...##...
11041 ; ######## ######## ######## .##..##. ########
11042 ; ######## ######## ###..### ######## ..####..
11043 ; ###..### ###..### .##..##. ######## ...##...
11044 ; ###..### .##..##. ######## .######.
11045 ; ######## ######## ######## ..####..
11046 ; ######## ######## ########
11047 ; ######## ######## ########
11048 ; ######## ######## ..####..
11049 ; ######## .######.
11050 ; .######. .######.
11051 ; .######.
11052 ;
11053 ; STARBASE LEFT (shape type 4, data in shape table PLSHAP2TAB)
11054 ; Numbers at top indicate the shape table offset of the first and last shape row
11055 ;
11056 ; $47..$50 $52..$5A $5B..$60 $50..$52 $50 $00 $00 $00
11057 ; .....### ......## ......## ......## ......## ........ ........ ........
11058 ; ...##### ....#### ......## ....####
11059 ; ...##### ....#### ....#### ......##
11060 ; .####### ..###### ..####.#
11061 ; ###.#.#. .#####.# ....####
11062 ; .####### ..###### ......##
11063 ; ...##### ....####
11064 ; ...##### .......#
11065 ; ......## .......#
11066 ; ......##
11067 ;
11068 ; TRANSFER VESSEL (shape type 5, data in shape table PLSHAP1TAB)
11069 ; Numbers at top indicate the shape table offset of the first and last shape row
11070 ;
11071 ; $43..$52 $53..$60 $61..$6B $6C..$74 $75..$79 $7A..$7D $75..$76 $7A..$7B
11072 ; ..####.. ...###.. ...##... ...#.... ...##... ...#.... ...##... ...#....
11073 ; ..####.. ...###.. ...##... ...#.... ...##... ...#.... ...##... ...#....
11074 ; ..#..#.. ...#.#.. ..####.. ..###... ..####.. ..###...
11075 ; ..####.. ..#####. ..####.. ..###... ...##... ...#....
11076 ; .######. ..#####. ..####.. ..###... ...##...
11077 ; .######. ..#####. ..####.. .#####..
11078 ; .######. ..#.#.#. .######. ..#.#...
11079 ; .#.##.#. .####### ..#..#.. ..#.#...
11080 ; ######## .####### ..#..#.. ..#.#...
11081 ; ######## ..#...#. ..#..#..
11082 ; .#....#. ..#...#. ..#..#..
11083 ; .#....#. ..#...#.
11084 ; .#....#. ..#...#.
11085 ; .#....#. ..#...#.
11086 ; .#....#.
11087 ; .#....#.
11088 ;
11089 ; METEOR (shape type 6, data in shape table PLSHAP1TAB)
11090 ; Numbers at top indicate the shape table offset of the first and last shape row
11091 ;
11092 ; $01..$10 $11..$1E $1F..$2A $2B..$34 $35..$3C $3D..$42 $75..$76 $7A..$7B
11093 ; ...##... ...#.... ...##... ...#.... ...#.... ...#.... ...##... ...#....
11094 ; ..####.. ..###... ..####.. ..###... ...##... ..###... ...##... ...#....
11095 ; .######. .#####.. ..####.. ..###... ..####.. ..###...
11096 ; .######. .#####.. .######. .#####.. ..#.##.. ..#.#...
11097 ; .###.##. #######. .##.###. .###.#.. ..####.. ..###...
11098 ; ####.### ##.####. .####.#. .#####.. ..####.. ...#....
11099 ; ##.##### ##.##.#. .######. .##.##.. ...##...
11100 ; ##.##### #####.#. .###.##. ..###... ....#...
11101 ; ######## ###.###. .######. ..###...
11102 ; ######## ###.###. ..####.. ...#....
11103 ; ####.### .#####.. ..####..
11104 ; .###.##. .#####.. ...##...
11105 ; .######. ..###...
11106 ; .######. ...#....
11107 ; ..####..
11108 ; ...##...
11109 ;
11110 ; ZYLON CRUISER (shape type 7, data in shape table PLSHAP2TAB)
11111 ; Numbers at top indicate the shape table offset of the first and last shape row
11112 ;
11113 ; $61..$69 $6A..$71 $72..$78 $79..$7E $7F..$82 $83..$85 $29..$2A $2B..$2C
11114 ; ...##... ...#.... ...##... ...#.... ...##... ...#.... ...##... ...#....
11115 ; ..####.. ..###... ..####.. ..###... ..####.. ..###... ...##... ...#....
11116 ; .######. .#####.. ..####.. ..###... ..#..#.. ..#.#...
11117 ; .######. .#####.. .##..##. .##.##.. ..#..#..
11118 ; ##.##.## ##.#.##. .##..##. .#...#..
11119 ; ##....## ##...##. .#....#. .#...#..
11120 ; #......# #.....#. .#....#.
11121 ; #......# #.....#.
11122 ; #......#
11123 ;
11124 ; ZYLON BASESTAR (shape type 8, data in shape table PLSHAP2TAB)
11125 ; Numbers at top indicate the shape table offset of the first and last shape row
11126 ;
11127 ; $86..$8F $90..$99 $9A..$A0 $A1..$A7 $A8..$AC $AD..$B0 $29..$2A $2B..$2C
11128 ; ...##... ...#.... ...##... ...#.... ...##... ...#.... ...##... ...#....
11129 ; ..####.. ..###... ..####.. ..###... ..####.. ..###... ...##... ...#....
11130 ; .######. .#####.. .######. .#####.. ...##... ..###...
11131 ; ######## #######. ...##... ...#.... ..####.. ...#....
11132 ; ...##... ..###... .######. .#####.. ...##...
11133 ; ...##... ..###... ..####.. ..###...
11134 ; ######## #######. ...##... ...#....
11135 ; .######. .#####..
11136 ; ..####.. ..###...
11137 ; ...##... ...#....
11138 ;
11139 ; HYPERWARP TARGET MARKER (shape type 9, data in shape table PLSHAP1TAB)
11140 ; Numbers at top indicate the shape table offset of the first and last shape row
11141 ;
11142 ; $C1..$CC $C1..$CC $C1..$CC $C1..$CC $C1..$CC $C1..$CC $75..$76 $C1..$CC
11143 ; ..#.#... ..#.#... ..#.#... ..#.#... ..#.#... ..#.#... ...##... ..#.#...
11144 ; ..#.#... ..#.#... ..#.#... ..#.#... ..#.#... ..#.#... ...##... ..#.#...
11145 ; ..#.#... ..#.#... ..#.#... ..#.#... ..#.#... ..#.#... ..#.#...
11146 ; ..#.#... ..#.#... ..#.#... ..#.#... ..#.#... ..#.#... ..#.#...
11147 ; ###.###. ###.###. ###.###. ###.###. ###.###. ###.###. ###.###.
11148 ; ........ ........ ........ ........ ........ ........ ........
11149 ; ........ ........ ........ ........ ........ ........ ........
11150 ; ###.###. ###.###. ###.###. ###.###. ###.###. ###.###. ###.###.
11151 ; ..#.#... ..#.#... ..#.#... ..#.#... ..#.#... ..#.#... ..#.#...
11152 ; ..#.#... ..#.#... ..#.#... ..#.#... ..#.#... ..#.#... ..#.#...
11153 ; ..#.#... ..#.#... ..#.#... ..#.#... ..#.#... ..#.#... ..#.#...
11154 ; ..#.#... ..#.#... ..#.#... ..#.#... ..#.#... ..#.#... ..#.#...
11155
11156 ;*** Shape type 0..9 offset table (10 shape cell offsets of shape type...) *****
BE2F 01111F2B 11157 PLSHAPOFFTAB .BYTE $01,$11,$1F,$2B,$35,$3D,$75,$7A ; ...0 into PLSHAP1TAB
BE33 353D757A
BE37 010D151B 11158 .BYTE $01,$0D,$15,$1B,$21,$25,$29,$2B ; ...1 into PLSHAP2TAB
BE3B 2125292B
BE3F 2D384136 11159 .BYTE $2D,$38,$41,$36,$36,$00,$00,$00 ; ...2 into PLSHAP2TAB
BE43 36000000
BE47 7E8E9DAA 11160 .BYTE $7E,$8E,$9D,$AA,$B4,$BC,$7B,$7A ; ...3 into PLSHAP1TAB
BE4B B4BC7B7A
BE4F 47525B50 11161 .BYTE $47,$52,$5B,$50,$50,$00,$00,$00 ; ...4 into PLSHAP2TAB
BE53 50000000
BE57 4353616C 11162 .BYTE $43,$53,$61,$6C,$75,$7A,$75,$7A ; ...5 into PLSHAP1TAB
BE5B 757A757A
BE5F 01111F2B 11163 .BYTE $01,$11,$1F,$2B,$35,$3D,$75,$7A ; ...6 into PLSHAP1TAB
BE63 353D757A
BE67 616A7279 11164 .BYTE $61,$6A,$72,$79,$7F,$83,$29,$2B ; ...7 into PLSHAP2TAB
BE6B 7F83292B
BE6F 86909AA1 11165 .BYTE $86,$90,$9A,$A1,$A8,$AD,$29,$2B ; ...8 into PLSHAP2TAB
BE73 A8AD292B
BE77 C1C1C1C1 11166 .BYTE $C1,$C1,$C1,$C1,$C1,$C1,$75,$C1 ; ...9 into PLSHAP1TAB
BE7B C1C175C1
11167
11168 ;*** Shape type 0..9 height table (10 shape cell heights of shape type...) *****
BE7F 0F0D0B09 11169 PLSHAPHEIGHTTAB .BYTE $0F,$0D,$0B,$09,$07,$05,$01,$01 ; ...0
BE83 07050101
BE87 0B070505 11170 .BYTE $0B,$07,$05,$05,$03,$03,$01,$01 ; ...1
BE8B 03030101
BE8F 09080502 11171 .BYTE $09,$08,$05,$02,$00,$00,$00,$00 ; ...2
BE93 00000000
BE97 0F0E0C09 11172 .BYTE $0F,$0E,$0C,$09,$07,$04,$02,$01 ; ...3
BE9B 07040201
BE9F 09080502 11173 .BYTE $09,$08,$05,$02,$00,$00,$00,$00 ; ...4
BEA3 00000000
BEA7 0F0D0A08 11174 .BYTE $0F,$0D,$0A,$08,$04,$03,$01,$01 ; ...5
BEAB 04030101
BEAF 0F0D0B09 11175 .BYTE $0F,$0D,$0B,$09,$07,$05,$01,$01 ; ...6
BEB3 07050101
BEB7 08070605 11176 .BYTE $08,$07,$06,$05,$03,$02,$01,$01 ; ...7
BEBB 03020101
BEBF 09090606 11177 .BYTE $09,$09,$06,$06,$04,$03,$01,$01 ; ...8
BEC3 04030101
BEC7 0B0B0B0B 11178 .BYTE $0B,$0B,$0B,$0B,$0B,$0B,$01,$0B ; ...9
BECB 0B0B010B
11179
11180 ;*** Keyboard codes to switch to Front or Aft view when Tracking Computer is on
BECF F8 11181 TRACKKEYSTAB .BYTE $F8 ; 'F' - Front view
BED0 FF 11182 .BYTE $FF ; 'A' - Aft view
11183
11184 ;*** Galactic Chart sector character codes (encoded in custom character set) ***
BED1 0C 11185 SECTORCHARTAB .BYTE CCS.BORDERSW ; Empty sector
BED2 1E 11186 .BYTE CCS.2ZYLONS ; Sector contains 1 Zylon ship
BED3 1E 11187 .BYTE CCS.2ZYLONS ; Sector contains 2 Zylon ships
BED4 1D 11188 .BYTE CCS.3ZYLONS ; Sector contains 3 Zylon ships
BED5 1C 11189 .BYTE CCS.4ZYLONS ; Sector contains 4 Zylon ships
BED6 1B 11190 .BYTE CCS.STARBASE ; Sector contains starbase
11191
11192 ;*** Mask to limit veer-off velocity of Hyperwarp Target Marker in hyperwarp ***
BED7 9F 11193 VEERMASKTAB .BYTE NEG!31 ; -31..+31 <KM/H> (unused)
BED8 BF 11194 .BYTE NEG!63 ; -63..+63 <KM/H> PILOT mission
BED9 DF 11195 .BYTE NEG!95 ; -95..+95 <KM/H> WARRIOR mission
BEDA FF 11196 .BYTE NEG!127 ; -127..+127 <KM/H> COMMANDER mission
11197
11198 ;*** Horizontal PLAYER offsets for PLAYER0..1 (STARBASE LEFT, STARBASE RIGHT) **
BEDB F8 11199 PLSTARBAOFFTAB .BYTE -8 ; -8 Player/Missile pixels
BEDC 08 11200 .BYTE 8 ; +8 Player/Missile pixels
11201
11202 ;*** Mission bonus table *******************************************************
BEDD 50 11203 BONUSTAB .BYTE 80 ; Mission complete NOVICE mission
BEDE 4C 11204 .BYTE 76 ; Mission complete PILOT mission
BEDF 3C 11205 .BYTE 60 ; Mission complete WARRIOR mission
BEE0 6F 11206 .BYTE 111 ; Mission complete COMMANDER mission
11207
BEE1 3C 11208 .BYTE 60 ; Mission aborted NOVICE mission
BEE2 3C 11209 .BYTE 60 ; Mission aborted PILOT mission
BEE3 32 11210 .BYTE 50 ; Mission aborted WARRIOR mission
BEE4 64 11211 .BYTE 100 ; Mission aborted COMMANDER mission
11212
BEE5 28 11213 .BYTE 40 ; Starship destroyed NOVICE mission
BEE6 32 11214 .BYTE 50 ; Starship destroyed PILOT mission
BEE7 28 11215 .BYTE 40 ; Starship destroyed WARRIOR mission
BEE8 5A 11216 .BYTE 90 ; Starship destroyed COMMANDER mission
11217
11218 ;*** Title phrase offsets of scored class rank *********************************
BEE9 A9 11219 RANKTAB .BYTE $29!EOS ; "GALACTIC COOK"
BEEA AA 11220 .BYTE $2A!EOS ; "GARBAGE SCOW CAPTAIN"
BEEB AA 11221 .BYTE $2A!EOS ; "GARBAGE SCOW CAPTAIN"
BEEC AB 11222 .BYTE $2B!EOS ; "ROOKIE"
BEED AB 11223 .BYTE $2B!EOS ; "ROOKIE"
BEEE AC 11224 .BYTE $2C!EOS ; "NOVICE"
BEEF AC 11225 .BYTE $2C!EOS ; "NOVICE"
BEF0 AD 11226 .BYTE $2D!EOS ; "ENSIGN"
BEF1 AD 11227 .BYTE $2D!EOS ; "ENSIGN"
BEF2 AE 11228 .BYTE $2E!EOS ; "PILOT"
BEF3 AE 11229 .BYTE $2E!EOS ; "PILOT"
BEF4 AF 11230 .BYTE $2F!EOS ; "ACE"
BEF5 B0 11231 .BYTE $30!EOS ; "LIEUTENANT"
BEF6 B1 11232 .BYTE $31!EOS ; "WARRIOR"
BEF7 B2 11233 .BYTE $32!EOS ; "CAPTAIN"
BEF8 B3 11234 .BYTE $33!EOS ; "COMMANDER"
BEF9 B3 11235 .BYTE $33!EOS ; "COMMANDER"
BEFA B9 11236 .BYTE $39!EOS ; "STAR COMMANDER"
BEFB B9 11237 .BYTE $39!EOS ; "STAR COMMANDER"
11238
11239 ;*** Scored class number table *************************************************
BEFC 95 11240 CLASSTAB .BYTE CCS.COL2!ROM.5 ; Class 5
BEFD 95 11241 .BYTE CCS.COL2!ROM.5 ; Class 5
BEFE 95 11242 .BYTE CCS.COL2!ROM.5 ; Class 5
BEFF 94 11243 .BYTE CCS.COL2!ROM.4 ; Class 4
BF00 94 11244 .BYTE CCS.COL2!ROM.4 ; Class 4
BF01 94 11245 .BYTE CCS.COL2!ROM.4 ; Class 4
BF02 94 11246 .BYTE CCS.COL2!ROM.4 ; Class 4
BF03 93 11247 .BYTE CCS.COL2!ROM.3 ; Class 3
BF04 93 11248 .BYTE CCS.COL2!ROM.3 ; Class 3
BF05 93 11249 .BYTE CCS.COL2!ROM.3 ; Class 3
BF06 92 11250 .BYTE CCS.COL2!ROM.2 ; Class 2
BF07 92 11251 .BYTE CCS.COL2!ROM.2 ; Class 2
BF08 92 11252 .BYTE CCS.COL2!ROM.2 ; Class 2
BF09 91 11253 .BYTE CCS.COL2!ROM.1 ; Class 1
BF0A 91 11254 .BYTE CCS.COL2!ROM.1 ; Class 1
BF0B 91 11255 .BYTE CCS.COL2!ROM.1 ; Class 1
11256
11257 ;*** Title phrase offsets of mission level *************************************
BF0C 4A 11258 MISSIONPHRTAB .BYTE $4A ; "NOVICE MISSION"
BF0D 4C 11259 .BYTE $4C ; "PILOT MISSION"
BF0E 4E 11260 .BYTE $4E ; "WARRIOR MISSION"
BF0F 50 11261 .BYTE $50 ; "COMMANDER MISSION"
11262
11263 ;*** Damage probability of subsystems depending on mission level ***************
BF10 00 11264 DAMAGEPROBTAB .BYTE 0 ; 0% ( 0:256) NOVICE mission
BF11 50 11265 .BYTE 80 ; 31% ( 80:256) PILOT mission
BF12 B4 11266 .BYTE 180 ; 70% (180:256) WARRIOR mission
BF13 FE 11267 .BYTE 254 ; 99% (254:256) COMMANDER mission
11268
11269 ;*** Title phrase offsets of damaged subsystems ********************************
BF14 55 11270 DAMAGEPHRTAB .BYTE $55 ; "PHOTON TORPEDOS DAMAGED"
BF15 5B 11271 .BYTE $5B ; "ENGINES DAMAGED"
BF16 61 11272 .BYTE $61 ; "SHIELDS DAMAGED"
BF17 67 11273 .BYTE $67 ; "COMPUTER DAMAGED"
BF18 6D 11274 .BYTE $6D ; "LONG RANGE SCAN DAMAGED"
BF19 71 11275 .BYTE $71 ; "SUB-SPACE RADIO DAMAGED"
11276
11277 ;*** Title phrase offsets of destroyed subsystems ******************************
BF1A 58 11278 DESTROYPHRTAB .BYTE $58 ; "PHOTON TORPEDOS DESTROYED"
BF1B 5E 11279 .BYTE $5E ; "ENGINES DESTROYED"
BF1C 64 11280 .BYTE $64 ; "SHIELDS DESTROYED"
BF1D 6A 11281 .BYTE $6A ; "COMPUTER DESTROYED"
BF1E 6F 11282 .BYTE $6F ; "LONG RANGE SCAN DESTROYED"
BF1F 73 11283 .BYTE $73 ; "SUB-SPACE RADIO DESTROYED"
11284
11285 ;*** 3 x 10-byte noise sound patterns (bytes 0..7 stored in reverse order) *****
11286 ;
11287 ; (9) AUDCTL ($D208) POKEY: Audio control
11288 ; (8) AUDF3 ($D204) POKEY: Audio channel 3 frequency
11289 ; (7) NOISETORPTIM ($DA) Timer for PHOTON TORPEDO LAUNCHED noise sound patterns
11290 ; (6) NOISEEXPLTIM ($DB) Timer for SHIELD and ZYLON EXPLOSION noise sound patterns
11291 ; (5) NOISEAUDC2 ($DC) Audio channel 1/2 control shadow register
11292 ; (4) NOISEAUDC3 ($DD) Audio channel 3 control shadow register
11293 ; (3) NOISEAUDF1 ($DE) Audio channel 1 frequency shadow register
11294 ; (2) NOISEAUDF2 ($DF) Audio channel 2 frequency shadow register
11295 ; (1) NOISEFRQINC ($E0) Audio channel 1/2 frequency increment
11296 ; (0) NOISELIFE ($E1) Noise sound pattern lifetime
11297 ;
11298 ; (0),(1),(2),(3),(4),(5),(6),(7),(8),(9)
BF20 18FF0200 11299 NOISEPATTAB .BYTE $18,$FF,$02,$00,$8A,$A0,$00,$08,$50,$00; PHOTON TORPEDO LAUNCHED
BF24 8AA00008
BF28 5000
BF2A 40400103 11300 .BYTE $40,$40,$01,$03,$88,$AF,$08,$00,$50,$04; SHIELD EXPLOSION
BF2E 88AF0800
BF32 5004
BF34 30400103 11301 .BYTE $30,$40,$01,$03,$84,$A8,$04,$00,$50,$04; ZYLON EXPLOSION
BF38 84A80400
BF3C 5004
11302
11303 ;*** 5 x 6-byte beeper sound patterns (bytes 0..5 stored in reverse order) *****
11304 ;
11305 ; (5) BEEPFRQIND ($D2) Running index into frequency table BEEPFRQTAB ($BF5C)
11306 ; (4) BEEPREPEAT ($D3) Number of times the beeper sound pattern sequence is repeated - 1
11307 ; (3) BEEPTONELIFE ($D4) Lifetime of tone in TICKs - 1
11308 ; (2) BEEPPAUSELIFE ($D5) Lifetime of pause in TICKs - 1 ($FF -> No pause)
11309 ; (1) BEEPPRIORITY ($D6) Beeper sound pattern priority. A playing beeper sound pattern is
11310 ; stopped if a beeper sound pattern of higher priority is about to be
11311 ; played. A value of 0 indicates that no beeper sound pattern is
11312 ; playing at the moment.
11313 ; (0) BEEPFRQSTART ($D7) Index to first byte of the beeper sound pattern frequency in table
11314 ; BEEPFRQTAB ($BF5C)
11315 ;
11316 ; Frequency-over-TICKs diagrams for all beeper sound patterns:
11317 ;
11318 ; HYPERWARP TRANSIT
11319 ;
11320 ; FRQ
11321 ; |
11322 ; $18 |-4--
11323 ; |
11324 ; $00 | -3-
11325 ; +-------> TICKS
11326 ; <13 x >
11327 ;
11328 ; RED ALERT
11329 ;
11330 ; FRQ
11331 ; |
11332 ; $60 | --------17-------
11333 ; |
11334 ; $40 |--------17-------
11335 ; |
11336 ; +----------------------------------> TICKS
11337 ; <-------------- 8 x ------------->
11338 ;
11339 ; ACKNOWLEDGE
11340 ;
11341 ; FRQ
11342 ; |
11343 ; $10 |-3- -3- -3-
11344 ; |
11345 ; $00 | -3- -3- -3-
11346 ; +------------------> TICKS
11347 ; <------ 1 x ----->
11348 ;
11349 ; DAMAGE REPORT (not to scale)
11350 ;
11351 ; FRQ
11352 ; |
11353 ; $40 |------------33-------------
11354 ; |
11355 ; $20 | ------------33-------------
11356 ; |
11357 ; +------------------------------------------------------> TICKS
11358 ; <------------------------ 3 x ----------------------->
11359 ;
11360 ; MESSAGE FROM STARBASE (not to scale)
11361 ;
11362 ; FRQ
11363 ; |
11364 ; $51 | -----33-----
11365 ; $48 |-----33-----
11366 ; $40 | -----33-----
11367 ; |
11368 ; $00 | --9-- --9-- --9--
11369 ; +----------------------------------------------------> TICKS
11370 ; <---------------------- 1 x ---------------------->
11371 ;
11372 ; (0),(1),(2),(3),(4),(5)
BF3E 02020203 11373 BEEPPATTAB .BYTE $02,$02,$02,$03,$0C,$02 ; HYPERWARP TRANSIT
BF42 0C02
BF44 0403FF10 11374 .BYTE $04,$03,$FF,$10,$07,$04 ; RED ALERT
BF48 0704
BF4A 07040202 11375 .BYTE $07,$04,$02,$02,$00,$07 ; ACKNOWLEDGE
BF4E 0007
BF50 0B05FF20 11376 .BYTE $0B,$05,$FF,$20,$02,$0B ; DAMAGE REPORT
BF54 020B
BF56 0E060820 11377 .BYTE $0E,$06,$08,$20,$00,$0E ; MESSAGE FROM STARBASE
BF5A 000E
11378
11379 ;*** Beeper sound pattern frequency table **************************************
BF5C 10FF 11380 BEEPFRQTAB .BYTE $10,$FF ; (unused) (!)
BF5E 18FF 11381 .BYTE $18,$FF ; HYPERWARP TRANSIT
BF60 4060FF 11382 .BYTE $40,$60,$FF ; RED ALERT
BF63 101010FF 11383 .BYTE $10,$10,$10,$FF ; ACKNOWLEDGE
BF67 4020FF 11384 .BYTE $40,$20,$FF ; DAMAGE REPORT
BF6A 484051FF 11385 .BYTE $48,$40,$51,$FF ; MESSAGE FROM STARBASE
11386
11387 ;*** Shape of blip in Attack Computer Display **********************************
BF6E 84 11388 BLIPSHAPTAB .BYTE $84 ; #....#..
BF6F B4 11389 .BYTE $B4 ; #.##.#..
BF70 FC 11390 .BYTE $FC ; ######..
BF71 B4 11391 .BYTE $B4 ; #.##.#..
BF72 84 11392 .BYTE $84 ; #....#..
11393
11394 ;*** Initial x-coordinate (high byte) of our starship's photon torpedo *********
BF73 FF 11395 BARRELXTAB .BYTE $FF ; Left barrel = -256 (-$FF00) <KM>
BF74 01 11396 .BYTE $01 ; Right barrel = +256 (+$0100) <KM>
11397
11398 ;*** Maximum photon torpedo hit z-coordinate (high byte) ***********************
BF75 0C 11399 HITMAXZTAB .BYTE $0C ; < 3328 ($0C**) <KM>
BF76 0C 11400 .BYTE $0C ; < 3328 ($0C**) <KM>
BF77 0C 11401 .BYTE $0C ; < 3328 ($0C**) <KM>
BF78 0C 11402 .BYTE $0C ; < 3328 ($0C**) <KM>
BF79 0E 11403 .BYTE $0E ; < 3840 ($0E**) <KM>
BF7A 0E 11404 .BYTE $0E ; < 3840 ($0E**) <KM>
BF7B 0E 11405 .BYTE $0E ; < 3840 ($0E**) <KM>
BF7C 20 11406 .BYTE $20 ; < 8448 ($20**) <KM>
11407
11408 ;*** Minimum photon torpedo hit z-coordinate (high byte) ***********************
BF7D 00 11409 HITMINZTAB .BYTE $00 ; >= 0 ($00**) <KM>
BF7E 00 11410 .BYTE $00 ; >= 0 ($00**) <KM>
BF7F 00 11411 .BYTE $00 ; >= 0 ($00**) <KM>
BF80 02 11412 .BYTE $02 ; >= 512 ($02**) <KM>
BF81 04 11413 .BYTE $04 ; >= 1024 ($04**) <KM>
BF82 06 11414 .BYTE $06 ; >= 1536 ($06**) <KM>
BF83 08 11415 .BYTE $08 ; >= 2048 ($08**) <KM>
BF84 0C 11416 .BYTE $0C ; >= 3072 ($0C**) <KM>
11417
11418 ;*** Velocity of homing Zylon photon torpedo ***********************************
BF85 81 11419 ZYLONHOMVELTAB .BYTE NEG!1 ; -1 <KM/H> NOVICE mission
BF86 84 11420 .BYTE NEG!4 ; -4 <KM/H> PILOT mission
BF87 88 11421 .BYTE NEG!8 ; -8 <KM/H> WARRIOR mission
BF88 94 11422 .BYTE NEG!20 ; -20 <KM/H> COMMANDER mission
11423
11424 ;*** Zylon shape type table ****************************************************
BF89 80 11425 ZYLONSHAPTAB .BYTE SHAP.ZBASESTAR ; ZYLON BASESTAR
BF8A 10 11426 .BYTE SHAP.ZFIGHTER ; ZYLON FIGHTER
BF8B 10 11427 .BYTE SHAP.ZFIGHTER ; ZYLON FIGHTER
BF8C 10 11428 .BYTE SHAP.ZFIGHTER ; ZYLON FIGHTER
BF8D 70 11429 .BYTE SHAP.ZCRUISER ; ZYLON CRUISER
BF8E 70 11430 .BYTE SHAP.ZCRUISER ; ZYLON CRUISER
BF8F 70 11431 .BYTE SHAP.ZCRUISER ; ZYLON CRUISER
BF90 10 11432 .BYTE SHAP.ZFIGHTER ; ZYLON FIGHTER
11433
11434 ;*** Zylon flight pattern table ************************************************
BF91 04 11435 ZYLONFLPATTAB .BYTE 4 ; Flight pattern 4
BF92 04 11436 .BYTE 4 ; Flight pattern 4
BF93 00 11437 .BYTE 0 ; Attack Flight Pattern 0
BF94 00 11438 .BYTE 0 ; Attack Flight Pattern 0
BF95 00 11439 .BYTE 0 ; Attack Flight Pattern 0
BF96 01 11440 .BYTE 1 ; Flight pattern 1
BF97 00 11441 .BYTE 0 ; Attack Flight Pattern 0
BF98 00 11442 .BYTE 0 ; Attack Flight Pattern 0
11443
11444 ;*** Zylon velocity table ******************************************************
BF99 3E 11445 ZYLONVELTAB .BYTE 62 ; +62 <KM/H>
BF9A 1E 11446 .BYTE 30 ; +30 <KM/H>
BF9B 10 11447 .BYTE 16 ; +16 <KM/H>
BF9C 08 11448 .BYTE 8 ; +8 <KM/H>
BF9D 04 11449 .BYTE 4 ; +4 <KM/H>
BF9E 02 11450 .BYTE 2 ; +2 <KM/H>
BF9F 01 11451 .BYTE 1 ; +1 <KM/H>
BFA0 00 11452 .BYTE 0 ; 0 <KM/H>
BFA1 00 11453 .BYTE 0 ; 0 <KM/H>
BFA2 81 11454 .BYTE NEG!1 ; -1 <KM/H>
BFA3 82 11455 .BYTE NEG!2 ; -2 <KM/H>
BFA4 84 11456 .BYTE NEG!4 ; -4 <KM/H>
BFA5 88 11457 .BYTE NEG!8 ; -8 <KM/H>
BFA6 90 11458 .BYTE NEG!16 ; -16 <KM/H>
BFA7 9E 11459 .BYTE NEG!30 ; -30 <KM/H>
BFA8 BE 11460 .BYTE NEG!62 ; -62 <KM/H>
11461
11462 ;*** PLAYFIELD colors (including PLAYFIELD colors during DLI) ******************
BFA9 A6 11463 PFCOLORTAB .BYTE $A6 ; PF0COLOR = {GREEN}
BFAA AA 11464 .BYTE $AA ; PF1COLOR = {LIGHT GREEN}
BFAB AF 11465 .BYTE $AF ; PF2COLOR = {VERY LIGHT GREEN}
BFAC 00 11466 .BYTE $00 ; PF3COLOR = {BLACK}
BFAD 00 11467 .BYTE $00 ; BGRCOLOR = {BLACK}
BFAE B8 11468 .BYTE $B8 ; PF0COLORDLI = {LIGHT MINT}
BFAF 5A 11469 .BYTE $5A ; PF1COLORDLI = {MEDIUM PINK}
BFB0 FC 11470 .BYTE $FC ; PF2COLORDLI = {LIGHT ORANGE}
BFB1 5E 11471 .BYTE $5E ; PF3COLORDLI = {LIGHT PINK}
BFB2 90 11472 .BYTE $90 ; BGRCOLORDLI = {DARK BLUE}
11473
11474 ;*** Vicinity mask table. Confines coordinates of space objects in sector ******
BFB3 FF 11475 VICINITYMASKTAB .BYTE $FF ; <= 65535 ($FF**) <KM>
BFB4 FF 11476 .BYTE $FF ; <= 65535 ($FF**) <KM>
BFB5 3F 11477 .BYTE $3F ; <= 16383 ($3F**) <KM>
BFB6 0F 11478 .BYTE $0F ; <= 4095 ($0F**) <KM>
BFB7 3F 11479 .BYTE $3F ; <= 16383 ($3F**) <KM>
BFB8 7F 11480 .BYTE $7F ; <= 32767 ($7F**) <KM>
BFB9 FF 11481 .BYTE $FF ; <= 65535 ($FF**) <KM>
BFBA FF 11482 .BYTE $FF ; <= 65535 ($FF**) <KM>
11483
11484 ;*** Movement probability of sector types in Galactic Chart ********************
BFBB 00 11485 MOVEPROBTAB .BYTE 0 ; Empty sector 0% ( 0:256)
BFBC FF 11486 .BYTE 255 ; 1 Zylon ship 100% (255:256)
BFBD FF 11487 .BYTE 255 ; 2 Zylon ships 100% (255:256)
BFBE C0 11488 .BYTE 192 ; 3 Zylon ships 75% (192:256)
BFBF 20 11489 .BYTE 32 ; 4 Zylon ships 13% ( 32:256)
11490
11491 ;*** Galactic Chart sector offset to adjacent sector ***************************
BFC0 F0 11492 COMPASSOFFTAB .BYTE -16 ; NORTH
BFC1 EF 11493 .BYTE -17 ; NORTHWEST
BFC2 FF 11494 .BYTE -1 ; WEST
BFC3 0F 11495 .BYTE 15 ; SOUTHWEST
BFC4 10 11496 .BYTE 16 ; SOUTH
BFC5 11 11497 .BYTE 17 ; SOUTHEAST
BFC6 01 11498 .BYTE 1 ; EAST
BFC7 F1 11499 .BYTE -15 ; NORTHEAST
BFC8 00 11500 .BYTE 0 ; CENTER
11501
11502 ;*** Homing velocities of photon torpedoes 0..1 depending on distance to target
BFC9 00 11503 HOMVELTAB .BYTE 0 ; +0 <KM/H>
BFCA 08 11504 .BYTE 8 ; +8 <KM/H>
BFCB 10 11505 .BYTE 16 ; +16 <KM/H>
BFCC 18 11506 .BYTE 24 ; +24 <KM/H>
BFCD 28 11507 .BYTE 40 ; +40 <KM/H>
BFCE 30 11508 .BYTE 48 ; +48 <KM/H>
BFCF 38 11509 .BYTE 56 ; +56 <KM/H>
BFD0 40 11510 .BYTE 64 ; +64 <KM/H>
11511
11512 ;*** PLAYER shape color table (bits B7..4 of color/brightness) *****************
BFD1 50 11513 PLSHAPCOLORTAB .BYTE $50 ; PHOTON TORPEDO = {PURPLE}
BFD2 00 11514 .BYTE $00 ; ZYLON FIGHTER = {GRAY}
BFD3 20 11515 .BYTE $20 ; STARBASE RIGHT = {ORANGE}
BFD4 20 11516 .BYTE $20 ; STARBASE CENTER = {ORANGE}
BFD5 20 11517 .BYTE $20 ; STARBASE LEFT = {ORANGE}
BFD6 00 11518 .BYTE $00 ; TRANSFER VESSEL = {GRAY}
BFD7 A0 11519 .BYTE $A0 ; METEOR = {GREEN}
BFD8 00 11520 .BYTE $00 ; ZYLON CRUISER = {GRAY}
BFD9 00 11521 .BYTE $00 ; ZYLON BASESTAR = {GRAY}
BFDA 9F 11522 .BYTE $9F ; HYPERWARP TARGET MARKER = {SKY BLUE}
11523
11524 ;*** PLAYER shape brightness table (bits B3..0 of color/brightness) ************
BFDB 0E 11525 PLSHAPBRITTAB .BYTE $0E ; ##############..
BFDC 0E 11526 .BYTE $0E ; ##############..
BFDD 0E 11527 .BYTE $0E ; ##############..
BFDE 0C 11528 .BYTE $0C ; ############....
BFDF 0C 11529 .BYTE $0C ; ############....
BFE0 0C 11530 .BYTE $0C ; ############....
BFE1 0A 11531 .BYTE $0A ; ##########......
BFE2 0A 11532 .BYTE $0A ; ##########......
BFE3 0A 11533 .BYTE $0A ; ##########......
BFE4 08 11534 .BYTE $08 ; ########........
BFE5 08 11535 .BYTE $08 ; ########........
BFE6 08 11536 .BYTE $08 ; ########........
BFE7 06 11537 .BYTE $06 ; ######..........
BFE8 06 11538 .BYTE $06 ; ######..........
BFE9 04 11539 .BYTE $04 ; ####............
BFEA 04 11540 .BYTE $04 ; ####............
11541
11542 ;*** PHOTON TORPEDO LAUNCHED noise bit and volume (stored in reverse order) ****
BFEB 8A 11543 NOISETORPVOLTAB .BYTE $8A ; ##########.....
BFEC 8F 11544 .BYTE $8F ; ###############
BFED 8D 11545 .BYTE $8D ; #############..
BFEE 8B 11546 .BYTE $8B ; ###########....
BFEF 89 11547 .BYTE $89 ; #########......
BFF0 87 11548 .BYTE $87 ; #######........
BFF1 85 11549 .BYTE $85 ; ######.........
BFF2 83 11550 .BYTE $83 ; ###............
11551
11552 ;*** PHOTON TORPEDO LAUNCHED noise frequency table (stored in reverse order) ***
BFF3 00 11553 NOISETORPFRQTAB .BYTE $00 ;
BFF4 04 11554 .BYTE $04 ;
BFF5 01 11555 .BYTE $01 ;
BFF6 04 11556 .BYTE $04 ;
BFF7 01 11557 .BYTE $01 ;
BFF8 04 11558 .BYTE $04 ;
BFF9 01 11559 .BYTE $01 ;
BFFA 04 11560 .BYTE $04 ;
11561
BFFB 07 11562 .BYTE $07 ; (unused)
11563
BFFC 00 11564 .BYTE $00 ; Always 0 for cartridges
BFFD 80 11565 .BYTE $80 ; On SYSTEM RESET jump to INITCOLD via
BFFE 4AA1 11566 .WORD INITCOLD ; Cartridge Initialization Address
SYMBOLS (SORTED BY NAME): 898
A980 ABORTWARP
A109 AFTHEADER
=0092 ARRVSECTOR
=D203 AUDC2
=D205 AUDC3
=D207 AUDC4
=D208 AUDCTL
=D200 AUDF1
=D202 AUDF2
=D204 AUDF3
=D206 AUDF4
=0087 BARRELNR
BF73 BARRELXTAB
B3A6 BEEP
=00D2 BEEPFRQIND
=00D7 BEEPFRQSTART
BF5C BEEPFRQTAB
=00D8 BEEPLIFE
BF3E BEEPPATTAB
=00D5 BEEPPAUSELIFE
=00D6 BEEPPRIORITY
=00D3 BEEPREPEAT
=00D9 BEEPTOGGLE
=00D4 BEEPTONELIFE
=00F6 BGRCOLOR
=00FB BGRCOLORDLI
=00A0 BLIPCOLUMN
=00A2 BLIPCYCLECNT
=00A1 BLIPROW
BF6E BLIPSHAPTAB
BEDD BONUSTAB
B1A7 CALCWARP
=0000 CCS.0
=0001 ?CCS.1
=0002 ?CCS.2
=001E CCS.2ZYLONS
=0003 ?CCS.3
=001D CCS.3ZYLONS
=0004 ?CCS.4
=001C CCS.4ZYLONS
=0005 ?CCS.5
=0006 ?CCS.6
=0007 ?CCS.7
=0008 ?CCS.8
=0009 CCS.9
=0018 CCS.BORDERS
=000C CCS.BORDERSW
=0019 CCS.BORDERW
=0017 ?CCS.C
=0040 CCS.COL1
=0080 CCS.COL2
=00C0 CCS.COL3
=000B CCS.COLON
=001A CCS.CORNERSW
=000D CCS.E
=000E CCS.INF
=0015 CCS.K
=000F CCS.MINUS
=0011 CCS.PHI
=0010 CCS.PLUS
=0013 CCS.R
=000A CCS.SPC
=001B CCS.STARBASE
=0016 CCS.T
=0014 CCS.THETA
=0012 CCS.V
A000 CHARSET
=D409 CHBASE
BEFC CLASSTAB
A98D CLEANUPWARP
=0074 CLOCKTIM
AE0F CLRMEM
AE0D CLRPLAYFIELD
AF3D COLLISION
=D016 COLPF0
=D012 COLPM0
BFC0 COMPASSOFFTAB
=D01F CONSOL
ACAF COPYPOSVEC
ACC1 COPYPOSXY
=0076 COUNT256
=0072 COUNT8
=00A7 CTRLDZYLON
=0090 CURRSECTOR
AEE1 DAMAGE
BF14 DAMAGEPHRTAB
BF10 DAMAGEPROBTAB
B86F DECENERGY
BF1A DESTROYPHRTAB
=00A4 DIRLEN
=006A DIVIDEND
=D402 DLIST
BA62 DLSTFRAG
BA75 DLSTFRAGAFT
BA7D DLSTFRAGFRONT
BA6A DLSTFRAGGC
BA6D DLSTFRAGLRS
BA8C DLSTFRAGOFFTAB
A12E DLSTGC
A718 DLSTHNDLR
=D400 DMACTL
ACE6 DOCKING
=0075 DOCKSTATE
=0080 DOWN
=007E DRAINATTCOMP
=0080 DRAINENGINES
BAD3 DRAINRATETAB
=007D DRAINSHIELDS
B4B9 DRAWGC
A782 DRAWLINE
A784 DRAWLINE2
A76F DRAWLINES
BAF9 DRAWLINESTAB
=0280 DSPLST
A987 ENDWARP
=007F ENERGYCNT
=0955 ENERGYD1
=0040 EOP
=0080 EOS
=0080 EOW
=0073 EXPLLIFE
=0063 FKEYCODE
B4E4 FLUSHGAMELOOP
BA90 FOURCOLORPIXEL
A1F3 GAMELOOP
B10A GAMEOVER
B121 GAMEOVER2
A11A GCHEADER
=08C9 GCMEMMAP
=0D35 GCPFMEM
=09A3 GCSTARDAT
=0995 GCSTATCOM
=0993 GCSTATENG
=0996 GCSTATLRS
=0992 GCSTATPHO
=0997 GCSTATRAD
=0994 GCSTATSHL
=098D GCTRGCNT
=0971 GCTXT
=097D GCWARPD1
=D01D GRACTL
=008A HITBADNESS
=D01E HITCLR
BF75 HITMAXZTAB
BF7D HITMINZTAB
AECA HOMINGVEL
BFC9 HOMVELTAB
=D004 HPOSM0
=D005 HPOSM1
=D006 HPOSM2
=D007 HPOSM3
=D000 HPOSP0
=D001 HPOSP1
=D002 HPOSP2
=D003 HPOSP3
=0094 HUNTSECTCOLUMN
=0093 HUNTSECTOR
=0095 HUNTSECTROW
=009F HUNTTIM
A89B HYPERWARP
=0066 IDLECNTHI
=0077 IDLECNTLO
A14A INITCOLD
A15C INITDEMO
AC6B INITEXPL
B3BA INITIALIZE
B764 INITPOSVEC
A15A INITSELECT
A15E INITSTART
A9B4 INITTRAIL
=D20E IRQEN
A751 IRQHNDLR
=00B8 ISBACKATTACK0
=00B9 ?ISBACKATTACK1
=0064 ISDEMOMODE
=00A3 ISINLOCKON
=007B ISSTARBASESECT
B7F1 ISSURROUNDED
=007C ISTRACKCOMPON
=0086 ISTRACKING
=0067 ISVBISYNC
=006D JOYSTICKDELTA
=00C8 JOYSTICKX
=00C9 JOYSTICKY
A47D JUMP001
A4A4 JUMP002
A579 JUMP003
A74B JUMP004
=D209 KBCODE
AFFE KEYBOARD
=00CA KEYCODE
BABE KEYTAB
=0950 KILLCNTD1
=006B L.ABSDIFFCOLUMN
=006B L.BITPAT
=006B L.COLORMASK
=006B L.COLUMNPOS
=006A L.CTRLDZYLON
=006A L.DELTAC
=006A L.DIRECTIONIND
=006E L.DIRSAV
=0068 L.DIVISOR
=006A L.FOURCOLORPIX
=006A L.GCMEMMAPIND
=006A L.HEIGHTCNT
=006A L.ISDESTROYED
=006A L.KEYCODE
=006E L.LOOPCNT
=006B L.LOOPCNT2
=006A L.MAXRNDXY
=0068 L.MEMPTR1
=006A L.MEMPTR2
=006A L.NEWSECTOR
=006A L.NUMBYTES
=006A L.PIXELBYTEOFF
=006D L.PIXELCOLUMN
=006D L.PIXELROW
=006B L.PLHIT
=006D L.QUOTIENT
=0068 L.RANGE
=006A L.RANGEINDEX
=006B L.SECTORCNT
=006A L.SECTORTYPE
=006C L.SHIFTSHAP
=006A L.SIGNCHAR
=006B L.TERM3HI
=006A L.TERM3LO
=006C L.TERM3SIGN
=006C L.TOKEN
=006E L.TRAILCNT
=006A L.VECCOMPIND
=006B L.VELOCITYHI
=006A L.VELSIGN
=006C L.VIEWDIR
=006A L.WARPARRVCOL
=006A L.WORD
=006E L.ZPOSOFF
=0088 LOCKONLIFE
=00C0 LONG
A165 LOOP001
A201 LOOP002
A227 LOOP003
A26A LOOP004
A277 LOOP005
A284 LOOP006
A291 LOOP007
A29E LOOP008
A2BA LOOP009
A2E0 LOOP010
A306 LOOP011
A327 LOOP012
A343 LOOP013
A389 LOOP014
A3A6 LOOP015
A3BD LOOP016
A3E4 LOOP017
A3EB LOOP018
A422 LOOP019
A428 LOOP020
A453 LOOP021
A4C0 LOOP022
A4E7 LOOP023
A4FC LOOP024
A593 LOOP025
A6F6 LOOP026
A730 LOOP027
A765 LOOP028
A78E LOOP029
A7CF LOOP030
A83A LOOP031
A83C LOOP032
A947 LOOP033
A9E5 LOOP034
AA52 LOOP035
AAB5 LOOP036
ABB3 LOOP037
ABCA LOOP038
ABFC LOOP039
AC73 LOOP040
ADCA LOOP041
ADD7 LOOP042
ADF4 LOOP043
ADFB LOOP044
AE1A LOOP045
AEB3 LOOP046
AEE7 LOOP047
AF3F LOOP048
AFD5 LOOP049
AFEC LOOP050
B011 LOOP051
B056 LOOP052
B1FE LOOP053
B200 LOOP054
B234 LOOP055
B276 LOOP056
B286 LOOP057
B2C1 LOOP058
B3AF LOOP059
B3BC LOOP060
B3EE LOOP061
B41B LOOP062
B441 LOOP063
B44C LOOP064
B488 LOOP065
B492 LOOP066
B4BD LOOP067
B51C LOOP068
B54E LOOP069
B57C LOOP070
B5C1 LOOP071
B5D1 LOOP072
B5EA LOOP073
B5EF LOOP074
B601 LOOP075
B632 LOOP076
B662 LOOP077
B664 LOOP078
B896 LOOP079
A0F8 LRSHEADER
=D008 M0PL
=D009 M1PL
=D00A M2PL
=D00B M3PL
AA79 MANEUVER
=0DE9 MAPTO80
=0EE9 MAPTOBCD99
=0079 MAXSPCOBJIND
=0068 MEMPTR
=00AA MILESTTIM0
=00AB ?MILESTTIM1
=00AE ?MILESTVELINDX0
=00AF ?MILESTVELINDX1
=00B0 ?MILESTVELINDY0
=00B1 ?MILESTVELINDY1
=00AC MILESTVELINDZ0
=00AD ?MILESTVELINDZ1
=0062 MISSIONLEVEL
BF0C MISSIONPHRTAB
ADF1 MODDLST
BFBB MOVEPROBTAB
BE29 MSGBITTAB
BE26 MSGOFFTAB
BE2C MSGONTAB
=0080 NEG
=0065 NEWTITLEPHR
=0071 NEWVELOCITY
=0096 NEWZYLONDIST
=D40E NMIEN
AEA8 NOISE
=00DC NOISEAUDC2
=00DD NOISEAUDC3
=00DE NOISEAUDF1
=00DF NOISEAUDF2
=00DB NOISEEXPLTIM
=00E0 NOISEFRQINC
=00E3 NOISEHITLIFE
=00E1 NOISELIFE
BF20 NOISEPATTAB
BFF3 NOISETORPFRQTAB
=00DA NOISETORPTIM
BFEB NOISETORPVOLTAB
=00E2 NOISEZYLONTIM
=0031 NUMSPCOBJ.ALL
=0011 NUMSPCOBJ.NORM
=0005 NUMSPCOBJ.PL
=000C NUMSPCOBJ.STARS
=007A OLDMAXSPCOBJIND
=0084 OLDTRIG0
=009E OLDZYLONDIST
=D00F P3PL
=D302 PACTL
=0949 PANELTXT
BB42 PANELTXTTAB
=00A6 PENCOLUMN
=00A5 PENROW
=00F2 PF0COLOR
=00F7 PF0COLORDLI
=00F3 ?PF1COLOR
=00F8 ?PF1COLORDLI
=00F4 PF2COLOR
=00F9 ?PF2COLORDLI
=00F5 ?PF3COLOR
=00FA ?PF3COLORDLI
BFA9 PFCOLORTAB
=1000 PFMEM
=1000 PFMEM.C0R0
=12A8 PFMEM.C0R17
=10C8 PFMEM.C0R5
=1B36 PFMEM.C120R71
=1BFE PFMEM.C120R76
=1C9E PFMEM.C120R80
=1D40 PFMEM.C128R84
=1D68 PFMEM.C128R85
=1D42 PFMEM.C136R84
=1D6A PFMEM.C136R85
=1C04 PFMEM.C144R76
=1CA4 PFMEM.C144R80
=17BB PFMEM.C76R49
=17E3 PFMEM.C76R50
=17BC PFMEM.C80R49
=17E4 PFMEM.C80R50
=0864 PFMEMROWHI
=0800 PFMEMROWLO
=0966 PHIC1
BBAA PHRASETAB
=0CEE PIXELBYTE
=0C8C PIXELBYTEOFF
=0C2A PIXELCOLUMN
BAB0 PIXELMASKTAB
=0C5B PIXELROW
=0BF9 PIXELROWNEW
=0CBD PIXELSAVE
=00EE PL0COLOR
=0C2A PL0COLUMN
=0400 PL0DATA
=0CBD PL0HEIGHT
=0CEE PL0HEIGHTNEW
=00E9 PL0LIFE
=0C5B PL0ROW
=0BF9 PL0ROWNEW
=00E4 PL0SHAPOFF
=0C8C PL0SHAPTYPE
=0B97 ?PL0XVEL
=0BC8 ?PL0YVEL
=0A40 PL0ZPOSHI
=0B66 ?PL0ZVEL
=00EF ?PL1COLOR
=0C2B PL1COLUMN
=0500 PL1DATA
=0CBE PL1HEIGHT
=0CEF PL1HEIGHTNEW
=00EA PL1LIFE
=0C5C PL1ROW
=0BFA PL1ROWNEW
=00E5 PL1SHAPOFF
=0C8D PL1SHAPTYPE
=0B98 ?PL1XVEL
=0BC9 ?PL1YVEL
=0B67 ?PL1ZVEL
=00F0 ?PL2COLOR
=0C2C PL2COLUMN
=0600 PL2DATA
=0CBF PL2HEIGHT
=0CF0 PL2HEIGHTNEW
=00EB PL2LIFE
=0C5D PL2ROW
=0BFB PL2ROWNEW
=00E6 PL2SHAPOFF
=0C8E PL2SHAPTYPE
=0A73 PL2XPOSHI
=0B06 ?PL2XPOSLO
=09E0 ?PL2XPOSSIGN
=0B99 PL2XVEL
=0AA4 PL2YPOSHI
=0B37 ?PL2YPOSLO
=0A11 PL2YPOSSIGN
=0BCA PL2YVEL
=0A42 PL2ZPOSHI
=0AD5 PL2ZPOSLO
=09AF PL2ZPOSSIGN
=0B68 PL2ZVEL
=00F1 ?PL3COLOR
=0C2D PL3COLUMN
=0700 PL3DATA
=0CC0 PL3HEIGHT
=0CF1 PL3HEIGHTNEW
=0082 PL3HIT
=00EC PL3LIFE
=0C5E PL3ROW
=0BFC PL3ROWNEW
=00E7 PL3SHAPOFF
=0C8F PL3SHAPTYPE
=0A74 PL3XPOSHI
=0B07 PL3XPOSLO
=09E1 PL3XPOSSIGN
=0B9A PL3XVEL
=0AA5 PL3YPOSHI
=0B38 PL3YPOSLO
=0A12 PL3YPOSSIGN
=0BCB PL3YVEL
=0A43 PL3ZPOSHI
=0AD6 PL3ZPOSLO
=09B0 PL3ZPOSSIGN
=0B69 PL3ZVEL
=0C2E PL4COLUMN
=0300 PL4DATA
=0CC1 PL4HEIGHT
=0CF2 PL4HEIGHTNEW
=0083 PL4HIT
=00ED PL4LIFE
=0C5F PL4ROW
=0BFD PL4ROWNEW
=00E8 PL4SHAPOFF
=0C90 PL4SHAPTYPE
=0A75 PL4XPOSHI
=0B08 ?PL4XPOSLO
=09E2 PL4XPOSSIGN
=0B9B PL4XVEL
=0AA6 PL4YPOSHI
=0B39 ?PL4YPOSLO
=0A13 PL4YPOSSIGN
=0BCC PL4YVEL
=0A44 PL4ZPOSHI
=0AD7 ?PL4ZPOSLO
=09B1 PL4ZPOSSIGN
=0B6A PL4ZVEL
B8DF PLCOLOROFFTAB
B8E4 PLSHAP1TAB
B9B1 PLSHAP2TAB
BFDB PLSHAPBRITTAB
BFD1 PLSHAPCOLORTAB
BE7F PLSHAPHEIGHTTAB
BE2F PLSHAPOFFTAB
BEDB PLSTARBAOFFTAB
=0089 PLTRACKED
=D407 PMBASE
=D300 PORTA
=D01B PRIOR
AA21 PROJECTION
=D20A RANDOM
=096C RANGEC1
BEE9 RANKTAB
=008B REDALERTLIFE
=0000 RIGHT
B7BE RNDINVXY
=0010 ROM.0
=0011 ROM.1
=0012 ROM.2
=0013 ROM.3
=0014 ROM.4
=0015 ROM.5
=0019 ROM.9
=0021 ROM.A
=0023 ROM.C
=001A ROM.COLON
=0024 ROM.D
=000E ROM.DOT
=0025 ROM.E
=0027 ROM.G
=002C ROM.L
=002E ROM.N
=0030 ROM.P
=0032 ROM.R
=0033 ROM.S
=0000 ROM.SPC
=0034 ROM.T
=0037 ROM.W
=0039 ROM.Y
=E000 ROMCHARSET
B69B ROTATE
=00CB SCORE
=00CE SCOREDCLASSIND
=00CD SCOREDRANKIND
B6FB SCREENCOLUMN
B71E SCREENROW
BED1 SECTORCHARTAB
BBA6 SECTORTYPETAB
B162 SELECTWARP
B223 SETTITLE
B045 SETVIEW
=0090 SHAP.HYPERWARP
=0060 SHAP.METEOR
=0030 SHAP.STARBASEC
=0020 SHAP.STARBASEL
=0040 SHAP.STARBASER
=0000 ?SHAP.TORPEDO
=0050 SHAP.TRANSVSSL
=0080 SHAP.ZBASESTAR
=0070 SHAP.ZCRUISER
=0010 SHAP.ZFIGHTER
=0081 SHIELDSCOLOR
=00D0 SHIPVIEW
B8A7 SHOWCOORD
B8CD SHOWDIGITS
=D20F SKCTL
A172 SKIP001
A21F SKIP002
A250 SKIP003
A262 SKIP004
A2C2 SKIP005
A2E8 SKIP006
A30E SKIP007
A39E SKIP008
A3BB SKIP009
A3C6 SKIP010
A3DF SKIP011
A3EA SKIP012
A3FE SKIP013
A43C SKIP014
A43F SKIP015
A473 SKIP016
A49A SKIP017
A4A7 SKIP018
A4AD SKIP019
A4CA SKIP020
A4DB SKIP021
A4E5 SKIP022
A4ED SKIP023
A503 SKIP024
A52A SKIP025
A52E SKIP026
A53E SKIP027
A548 SKIP028
A569 SKIP029
A58D SKIP030
A5A3 SKIP031
A5A5 SKIP032
A5AB SKIP033
A5D0 SKIP034
A600 SKIP035
A60C SKIP036
A61B SKIP037
A635 SKIP038
A687 SKIP039
A69B SKIP040
A6B7 SKIP041
A6C2 SKIP042
A6E9 SKIP043
A6EA SKIP044
A6F2 SKIP045
A715 SKIP046
A728 SKIP047
A77A SKIP048
A781 SKIP049
A7B8 SKIP050
A7BA SKIP051
A7E1 SKIP052
A7E9 SKIP053
A7EC SKIP054
A804 SKIP055
A80A SKIP056
A821 SKIP057
A827 SKIP058
A830 SKIP059
A850 SKIP060
A85F SKIP061
A898 SKIP062
A8AC SKIP063
A8E8 SKIP064
A8EC SKIP065
A900 SKIP066
A901 SKIP067
A915 SKIP068
A91E SKIP069
A96F SKIP070
A97F SKIP071
A9A6 SKIP072
AA1A SKIP073
AA20 SKIP074
AA40 SKIP075
AA66 SKIP076
AA6F SKIP077
AA78 SKIP078
AA90 SKIP079
AAB3 SKIP080
AAC8 SKIP081
AACF SKIP082
AAD5 SKIP083
AADD SKIP084
AAE0 SKIP085
AAF4 SKIP086
AB00 SKIP087
AB03 SKIP088
AB09 SKIP089
AB11 SKIP090
AB36 SKIP091
AB37 SKIP092
AB66 SKIP093
AB84 SKIP094
AB98 SKIP095
AB9C SKIP096
ABAE SKIP097
ABBA SKIP098
ABC4 SKIP099
ABDD SKIP100
ABE1 SKIP101
ABE5 SKIP102
ABE9 SKIP103
ABEB SKIP104
ABFA SKIP105
AC08 SKIP106
AC0A SKIP107
AC31 SKIP108
AC32 SKIP109
AC4F SKIP110
ACE5 SKIP111
ACF3 SKIP112
AD12 SKIP113
AD26 SKIP114
AD35 SKIP115
AD61 SKIP116
AD6C SKIP117
AD70 SKIP118
AD71 SKIP119
AD82 SKIP120
ADB8 SKIP121
ADB9 SKIP122
AE03 SKIP123
AE40 SKIP124
AE41 SKIP125
AE56 SKIP126
AE58 SKIP127
AE66 SKIP128
AEB1 SKIP129
AEC9 SKIP130
AED2 SKIP131
AEDA SKIP132
AF10 SKIP133
AF19 SKIP134
AF1E SKIP135
AF32 SKIP136
AF3C SKIP137
AF43 SKIP138
AF58 SKIP139
AF64 SKIP140
AF6F SKIP141
AF94 SKIP142
AFC6 SKIP143
AFE7 SKIP144
AFF3 SKIP145
AFFD SKIP146
B020 SKIP147
B02B SKIP148
B036 SKIP149
B040 SKIP150
B041 SKIP151
B060 SKIP152
B073 SKIP153
B082 SKIP154
B096 SKIP155
B099 SKIP156
B0E6 SKIP157
B0ED SKIP158
B0FB SKIP159
B0FC SKIP160
B106 SKIP161
B14A SKIP162
B15A SKIP163
B15D SKIP164
B161 SKIP165
B16A SKIP166
B16B SKIP167
B173 SKIP168
B1BE SKIP169
B1C8 SKIP170
B1D3 SKIP171
B1E0 SKIP172
B212 SKIP173
B21E SKIP174
B21F SKIP175
B22E SKIP176
B23A SKIP177
B249 SKIP178
B25F SKIP179
B268 SKIP180
B27C SKIP181
B2A2 SKIP182
B2A8 SKIP183
B2E1 SKIP184
B2E6 SKIP185
B2F3 SKIP186
B32B SKIP187
B337 SKIP188
B349 SKIP189
B357 SKIP190
B369 SKIP191
B397 SKIP192
B39F SKIP193
B3B9 SKIP194
B3CA SKIP195
B47C SKIP196
B4C6 SKIP197
B4F5 SKIP198
B50F SKIP199
B511 SKIP200
B516 SKIP201
B51A SKIP202
B527 SKIP203
B536 SKIP204
B53E SKIP205
B544 SKIP206
B562 SKIP207
B565 SKIP208
B569 SKIP209
B56A SKIP210
B574 SKIP211
B59A SKIP212
B5B0 SKIP213
B5BB SKIP214
B5DA SKIP215
B619 SKIP216
B61C SKIP217
B61D SKIP218
B644 SKIP219
B655 SKIP220
B68D SKIP221
B68F SKIP222
B698 SKIP223
B6A4 SKIP224
B6E1 SKIP225
B709 SKIP226
B717 SKIP227
B72E SKIP228
B73E SKIP229
B745 SKIP230
B74A SKIP231
B753 SKIP232
B75A SKIP233
B763 SKIP234
B785 SKIP235
B7A9 SKIP236
B7D7 SKIP237
B7F0 SKIP238
B803 SKIP239
B810 SKIP240
B812 SKIP241
B822 SKIP242
B85C SKIP243
B88C SKIP244
B88E SKIP245
B8A6 SKIP246
B8BD SKIP247
B2AB SOUND
BAF5 STICKINCTAB
=D209 STIMER
=0960 THETAC1
=00CF TITLELIFE
=00D1 TITLEPHR
=0D1F TITLETXT
=00BE TORPEDODELAY
=095A TRACKC1
=095C TRACKDIGIT
BECF TRACKKEYSTAB
=00C2 TRAILDELAY
=00C3 TRAILIND
=D010 TRIG0
AE29 TRIGGER
A7BF UPDATTCOMP
B804 UPDPANEL
B07B UPDSCREEN
B216 UPDTITLE
A6D1 VBIHNDLR
=D40B VCOUNT
=0200 VDSLST
=00C6 VEERMASK
BED7 VEERMASKTAB
=094B VELOCD1
=00C1 VELOCITYHI
=0070 VELOCITYLO
BAB4 VELOCITYTAB
=00C7 VICINITYMASK
BFB3 VICINITYMASKTAB
BE22 VIEWMODETAB
=0216 VIMIRQ
=0222 VVBLKI
=008F WARPARRVCOLUMN
=008E WARPARRVROW
=008D WARPDEPRCOLUMN
=008C WARPDEPRROW
=0091 WARPENERGY
BADD WARPENERGYTAB
BB3A WARPSTARXTAB
BB3E WARPSTARYTAB
=00C0 WARPSTATE
=00C4 WARPTEMPCOLUMN
=00C5 WARPTEMPROW
BC2B WORDTAB
=D40A WSYNC
=0A71 XPOSHI
=0B04 XPOSLO
=09DE XPOSSIGN
=0B97 XVEL
=0AA2 YPOSHI
=0B35 YPOSLO
=0A0F YPOSSIGN
=0BC8 YVEL
=0A40 ZPOSHI
=0AD3 ZPOSLO
=09AD ZPOSSIGN
=0B66 ZVEL
=00BF ZYLONATTACKER
=00A8 ZYLONFLPAT0
=00A9 ?ZYLONFLPAT1
BF91 ZYLONFLPATTAB
BF85 ZYLONHOMVELTAB
BF89 ZYLONSHAPTAB
=00BA ZYLONTIMX0
=00BB ?ZYLONTIMX1
=00BC ?ZYLONTIMY0
=00BD ?ZYLONTIMY1
=0078 ZYLONUNITTIM
=00B4 ZYLONVELINDX0
=00B5 ?ZYLONVELINDX1
=00B6 ?ZYLONVELINDY0
=00B7 ?ZYLONVELINDY1
=00B2 ZYLONVELINDZ0
=00B3 ?ZYLONVELINDZ1
BF99 ZYLONVELTAB
SYMBOLS (SORTED BY VALUE): 898
=0000 CCS.0
=0000 RIGHT
=0000 ROM.SPC
=0000 ?SHAP.TORPEDO
=0001 ?CCS.1
=0002 ?CCS.2
=0003 ?CCS.3
=0004 ?CCS.4
=0005 ?CCS.5
=0005 NUMSPCOBJ.PL
=0006 ?CCS.6
=0007 ?CCS.7
=0008 ?CCS.8
=0009 CCS.9
=000A CCS.SPC
=000B CCS.COLON
=000C CCS.BORDERSW
=000C NUMSPCOBJ.STARS
=000D CCS.E
=000E CCS.INF
=000E ROM.DOT
=000F CCS.MINUS
=0010 CCS.PLUS
=0010 ROM.0
=0010 SHAP.ZFIGHTER
=0011 CCS.PHI
=0011 NUMSPCOBJ.NORM
=0011 ROM.1
=0012 CCS.V
=0012 ROM.2
=0013 CCS.R
=0013 ROM.3
=0014 CCS.THETA
=0014 ROM.4
=0015 CCS.K
=0015 ROM.5
=0016 CCS.T
=0017 ?CCS.C
=0018 CCS.BORDERS
=0019 CCS.BORDERW
=0019 ROM.9
=001A CCS.CORNERSW
=001A ROM.COLON
=001B CCS.STARBASE
=001C CCS.4ZYLONS
=001D CCS.3ZYLONS
=001E CCS.2ZYLONS
=0020 SHAP.STARBASEL
=0021 ROM.A
=0023 ROM.C
=0024 ROM.D
=0025 ROM.E
=0027 ROM.G
=002C ROM.L
=002E ROM.N
=0030 ROM.P
=0030 SHAP.STARBASEC
=0031 NUMSPCOBJ.ALL
=0032 ROM.R
=0033 ROM.S
=0034 ROM.T
=0037 ROM.W
=0039 ROM.Y
=0040 CCS.COL1
=0040 EOP
=0040 SHAP.STARBASER
=0050 SHAP.TRANSVSSL
=0060 SHAP.METEOR
=0062 MISSIONLEVEL
=0063 FKEYCODE
=0064 ISDEMOMODE
=0065 NEWTITLEPHR
=0066 IDLECNTHI
=0067 ISVBISYNC
=0068 L.DIVISOR
=0068 L.MEMPTR1
=0068 L.RANGE
=0068 MEMPTR
=006A DIVIDEND
=006A L.CTRLDZYLON
=006A L.DELTAC
=006A L.DIRECTIONIND
=006A L.FOURCOLORPIX
=006A L.GCMEMMAPIND
=006A L.HEIGHTCNT
=006A L.ISDESTROYED
=006A L.KEYCODE
=006A L.MAXRNDXY
=006A L.MEMPTR2
=006A L.NEWSECTOR
=006A L.NUMBYTES
=006A L.PIXELBYTEOFF
=006A L.RANGEINDEX
=006A L.SECTORTYPE
=006A L.SIGNCHAR
=006A L.TERM3LO
=006A L.VECCOMPIND
=006A L.VELSIGN
=006A L.WARPARRVCOL
=006A L.WORD
=006B L.ABSDIFFCOLUMN
=006B L.BITPAT
=006B L.COLORMASK
=006B L.COLUMNPOS
=006B L.LOOPCNT2
=006B L.PLHIT
=006B L.SECTORCNT
=006B L.TERM3HI
=006B L.VELOCITYHI
=006C L.SHIFTSHAP
=006C L.TERM3SIGN
=006C L.TOKEN
=006C L.VIEWDIR
=006D JOYSTICKDELTA
=006D L.PIXELCOLUMN
=006D L.PIXELROW
=006D L.QUOTIENT
=006E L.DIRSAV
=006E L.LOOPCNT
=006E L.TRAILCNT
=006E L.ZPOSOFF
=0070 SHAP.ZCRUISER
=0070 VELOCITYLO
=0071 NEWVELOCITY
=0072 COUNT8
=0073 EXPLLIFE
=0074 CLOCKTIM
=0075 DOCKSTATE
=0076 COUNT256
=0077 IDLECNTLO
=0078 ZYLONUNITTIM
=0079 MAXSPCOBJIND
=007A OLDMAXSPCOBJIND
=007B ISSTARBASESECT
=007C ISTRACKCOMPON
=007D DRAINSHIELDS
=007E DRAINATTCOMP
=007F ENERGYCNT
=0080 CCS.COL2
=0080 DOWN
=0080 DRAINENGINES
=0080 EOS
=0080 EOW
=0080 NEG
=0080 SHAP.ZBASESTAR
=0081 SHIELDSCOLOR
=0082 PL3HIT
=0083 PL4HIT
=0084 OLDTRIG0
=0086 ISTRACKING
=0087 BARRELNR
=0088 LOCKONLIFE
=0089 PLTRACKED
=008A HITBADNESS
=008B REDALERTLIFE
=008C WARPDEPRROW
=008D WARPDEPRCOLUMN
=008E WARPARRVROW
=008F WARPARRVCOLUMN
=0090 CURRSECTOR
=0090 SHAP.HYPERWARP
=0091 WARPENERGY
=0092 ARRVSECTOR
=0093 HUNTSECTOR
=0094 HUNTSECTCOLUMN
=0095 HUNTSECTROW
=0096 NEWZYLONDIST
=009E OLDZYLONDIST
=009F HUNTTIM
=00A0 BLIPCOLUMN
=00A1 BLIPROW
=00A2 BLIPCYCLECNT
=00A3 ISINLOCKON
=00A4 DIRLEN
=00A5 PENROW
=00A6 PENCOLUMN
=00A7 CTRLDZYLON
=00A8 ZYLONFLPAT0
=00A9 ?ZYLONFLPAT1
=00AA MILESTTIM0
=00AB ?MILESTTIM1
=00AC MILESTVELINDZ0
=00AD ?MILESTVELINDZ1
=00AE ?MILESTVELINDX0
=00AF ?MILESTVELINDX1
=00B0 ?MILESTVELINDY0
=00B1 ?MILESTVELINDY1
=00B2 ZYLONVELINDZ0
=00B3 ?ZYLONVELINDZ1
=00B4 ZYLONVELINDX0
=00B5 ?ZYLONVELINDX1
=00B6 ?ZYLONVELINDY0
=00B7 ?ZYLONVELINDY1
=00B8 ISBACKATTACK0
=00B9 ?ISBACKATTACK1
=00BA ZYLONTIMX0
=00BB ?ZYLONTIMX1
=00BC ?ZYLONTIMY0
=00BD ?ZYLONTIMY1
=00BE TORPEDODELAY
=00BF ZYLONATTACKER
=00C0 CCS.COL3
=00C0 LONG
=00C0 WARPSTATE
=00C1 VELOCITYHI
=00C2 TRAILDELAY
=00C3 TRAILIND
=00C4 WARPTEMPCOLUMN
=00C5 WARPTEMPROW
=00C6 VEERMASK
=00C7 VICINITYMASK
=00C8 JOYSTICKX
=00C9 JOYSTICKY
=00CA KEYCODE
=00CB SCORE
=00CD SCOREDRANKIND
=00CE SCOREDCLASSIND
=00CF TITLELIFE
=00D0 SHIPVIEW
=00D1 TITLEPHR
=00D2 BEEPFRQIND
=00D3 BEEPREPEAT
=00D4 BEEPTONELIFE
=00D5 BEEPPAUSELIFE
=00D6 BEEPPRIORITY
=00D7 BEEPFRQSTART
=00D8 BEEPLIFE
=00D9 BEEPTOGGLE
=00DA NOISETORPTIM
=00DB NOISEEXPLTIM
=00DC NOISEAUDC2
=00DD NOISEAUDC3
=00DE NOISEAUDF1
=00DF NOISEAUDF2
=00E0 NOISEFRQINC
=00E1 NOISELIFE
=00E2 NOISEZYLONTIM
=00E3 NOISEHITLIFE
=00E4 PL0SHAPOFF
=00E5 PL1SHAPOFF
=00E6 PL2SHAPOFF
=00E7 PL3SHAPOFF
=00E8 PL4SHAPOFF
=00E9 PL0LIFE
=00EA PL1LIFE
=00EB PL2LIFE
=00EC PL3LIFE
=00ED PL4LIFE
=00EE PL0COLOR
=00EF ?PL1COLOR
=00F0 ?PL2COLOR
=00F1 ?PL3COLOR
=00F2 PF0COLOR
=00F3 ?PF1COLOR
=00F4 PF2COLOR
=00F5 ?PF3COLOR
=00F6 BGRCOLOR
=00F7 PF0COLORDLI
=00F8 ?PF1COLORDLI
=00F9 ?PF2COLORDLI
=00FA ?PF3COLORDLI
=00FB BGRCOLORDLI
=0200 VDSLST
=0216 VIMIRQ
=0222 VVBLKI
=0280 DSPLST
=0300 PL4DATA
=0400 PL0DATA
=0500 PL1DATA
=0600 PL2DATA
=0700 PL3DATA
=0800 PFMEMROWLO
=0864 PFMEMROWHI
=08C9 GCMEMMAP
=0949 PANELTXT
=094B VELOCD1
=0950 KILLCNTD1
=0955 ENERGYD1
=095A TRACKC1
=095C TRACKDIGIT
=0960 THETAC1
=0966 PHIC1
=096C RANGEC1
=0971 GCTXT
=097D GCWARPD1
=098D GCTRGCNT
=0992 GCSTATPHO
=0993 GCSTATENG
=0994 GCSTATSHL
=0995 GCSTATCOM
=0996 GCSTATLRS
=0997 GCSTATRAD
=09A3 GCSTARDAT
=09AD ZPOSSIGN
=09AF PL2ZPOSSIGN
=09B0 PL3ZPOSSIGN
=09B1 PL4ZPOSSIGN
=09DE XPOSSIGN
=09E0 ?PL2XPOSSIGN
=09E1 PL3XPOSSIGN
=09E2 PL4XPOSSIGN
=0A0F YPOSSIGN
=0A11 PL2YPOSSIGN
=0A12 PL3YPOSSIGN
=0A13 PL4YPOSSIGN
=0A40 PL0ZPOSHI
=0A40 ZPOSHI
=0A42 PL2ZPOSHI
=0A43 PL3ZPOSHI
=0A44 PL4ZPOSHI
=0A71 XPOSHI
=0A73 PL2XPOSHI
=0A74 PL3XPOSHI
=0A75 PL4XPOSHI
=0AA2 YPOSHI
=0AA4 PL2YPOSHI
=0AA5 PL3YPOSHI
=0AA6 PL4YPOSHI
=0AD3 ZPOSLO
=0AD5 PL2ZPOSLO
=0AD6 PL3ZPOSLO
=0AD7 ?PL4ZPOSLO
=0B04 XPOSLO
=0B06 ?PL2XPOSLO
=0B07 PL3XPOSLO
=0B08 ?PL4XPOSLO
=0B35 YPOSLO
=0B37 ?PL2YPOSLO
=0B38 PL3YPOSLO
=0B39 ?PL4YPOSLO
=0B66 ?PL0ZVEL
=0B66 ZVEL
=0B67 ?PL1ZVEL
=0B68 PL2ZVEL
=0B69 PL3ZVEL
=0B6A PL4ZVEL
=0B97 ?PL0XVEL
=0B97 XVEL
=0B98 ?PL1XVEL
=0B99 PL2XVEL
=0B9A PL3XVEL
=0B9B PL4XVEL
=0BC8 ?PL0YVEL
=0BC8 YVEL
=0BC9 ?PL1YVEL
=0BCA PL2YVEL
=0BCB PL3YVEL
=0BCC PL4YVEL
=0BF9 PIXELROWNEW
=0BF9 PL0ROWNEW
=0BFA PL1ROWNEW
=0BFB PL2ROWNEW
=0BFC PL3ROWNEW
=0BFD PL4ROWNEW
=0C2A PIXELCOLUMN
=0C2A PL0COLUMN
=0C2B PL1COLUMN
=0C2C PL2COLUMN
=0C2D PL3COLUMN
=0C2E PL4COLUMN
=0C5B PIXELROW
=0C5B PL0ROW
=0C5C PL1ROW
=0C5D PL2ROW
=0C5E PL3ROW
=0C5F PL4ROW
=0C8C PIXELBYTEOFF
=0C8C PL0SHAPTYPE
=0C8D PL1SHAPTYPE
=0C8E PL2SHAPTYPE
=0C8F PL3SHAPTYPE
=0C90 PL4SHAPTYPE
=0CBD PIXELSAVE
=0CBD PL0HEIGHT
=0CBE PL1HEIGHT
=0CBF PL2HEIGHT
=0CC0 PL3HEIGHT
=0CC1 PL4HEIGHT
=0CEE PIXELBYTE
=0CEE PL0HEIGHTNEW
=0CEF PL1HEIGHTNEW
=0CF0 PL2HEIGHTNEW
=0CF1 PL3HEIGHTNEW
=0CF2 PL4HEIGHTNEW
=0D1F TITLETXT
=0D35 GCPFMEM
=0DE9 MAPTO80
=0EE9 MAPTOBCD99
=1000 PFMEM
=1000 PFMEM.C0R0
=10C8 PFMEM.C0R5
=12A8 PFMEM.C0R17
=17BB PFMEM.C76R49
=17BC PFMEM.C80R49
=17E3 PFMEM.C76R50
=17E4 PFMEM.C80R50
=1B36 PFMEM.C120R71
=1BFE PFMEM.C120R76
=1C04 PFMEM.C144R76
=1C9E PFMEM.C120R80
=1CA4 PFMEM.C144R80
=1D40 PFMEM.C128R84
=1D42 PFMEM.C136R84
=1D68 PFMEM.C128R85
=1D6A PFMEM.C136R85
A000 CHARSET
A0F8 LRSHEADER
A109 AFTHEADER
A11A GCHEADER
A12E DLSTGC
A14A INITCOLD
A15A INITSELECT
A15C INITDEMO
A15E INITSTART
A165 LOOP001
A172 SKIP001
A1F3 GAMELOOP
A201 LOOP002
A21F SKIP002
A227 LOOP003
A250 SKIP003
A262 SKIP004
A26A LOOP004
A277 LOOP005
A284 LOOP006
A291 LOOP007
A29E LOOP008
A2BA LOOP009
A2C2 SKIP005
A2E0 LOOP010
A2E8 SKIP006
A306 LOOP011
A30E SKIP007
A327 LOOP012
A343 LOOP013
A389 LOOP014
A39E SKIP008
A3A6 LOOP015
A3BB SKIP009
A3BD LOOP016
A3C6 SKIP010
A3DF SKIP011
A3E4 LOOP017
A3EA SKIP012
A3EB LOOP018
A3FE SKIP013
A422 LOOP019
A428 LOOP020
A43C SKIP014
A43F SKIP015
A453 LOOP021
A473 SKIP016
A47D JUMP001
A49A SKIP017
A4A4 JUMP002
A4A7 SKIP018
A4AD SKIP019
A4C0 LOOP022
A4CA SKIP020
A4DB SKIP021
A4E5 SKIP022
A4E7 LOOP023
A4ED SKIP023
A4FC LOOP024
A503 SKIP024
A52A SKIP025
A52E SKIP026
A53E SKIP027
A548 SKIP028
A569 SKIP029
A579 JUMP003
A58D SKIP030
A593 LOOP025
A5A3 SKIP031
A5A5 SKIP032
A5AB SKIP033
A5D0 SKIP034
A600 SKIP035
A60C SKIP036
A61B SKIP037
A635 SKIP038
A687 SKIP039
A69B SKIP040
A6B7 SKIP041
A6C2 SKIP042
A6D1 VBIHNDLR
A6E9 SKIP043
A6EA SKIP044
A6F2 SKIP045
A6F6 LOOP026
A715 SKIP046
A718 DLSTHNDLR
A728 SKIP047
A730 LOOP027
A74B JUMP004
A751 IRQHNDLR
A765 LOOP028
A76F DRAWLINES
A77A SKIP048
A781 SKIP049
A782 DRAWLINE
A784 DRAWLINE2
A78E LOOP029
A7B8 SKIP050
A7BA SKIP051
A7BF UPDATTCOMP
A7CF LOOP030
A7E1 SKIP052
A7E9 SKIP053
A7EC SKIP054
A804 SKIP055
A80A SKIP056
A821 SKIP057
A827 SKIP058
A830 SKIP059
A83A LOOP031
A83C LOOP032
A850 SKIP060
A85F SKIP061
A898 SKIP062
A89B HYPERWARP
A8AC SKIP063
A8E8 SKIP064
A8EC SKIP065
A900 SKIP066
A901 SKIP067
A915 SKIP068
A91E SKIP069
A947 LOOP033
A96F SKIP070
A97F SKIP071
A980 ABORTWARP
A987 ENDWARP
A98D CLEANUPWARP
A9A6 SKIP072
A9B4 INITTRAIL
A9E5 LOOP034
AA1A SKIP073
AA20 SKIP074
AA21 PROJECTION
AA40 SKIP075
AA52 LOOP035
AA66 SKIP076
AA6F SKIP077
AA78 SKIP078
AA79 MANEUVER
AA90 SKIP079
AAB3 SKIP080
AAB5 LOOP036
AAC8 SKIP081
AACF SKIP082
AAD5 SKIP083
AADD SKIP084
AAE0 SKIP085
AAF4 SKIP086
AB00 SKIP087
AB03 SKIP088
AB09 SKIP089
AB11 SKIP090
AB36 SKIP091
AB37 SKIP092
AB66 SKIP093
AB84 SKIP094
AB98 SKIP095
AB9C SKIP096
ABAE SKIP097
ABB3 LOOP037
ABBA SKIP098
ABC4 SKIP099
ABCA LOOP038
ABDD SKIP100
ABE1 SKIP101
ABE5 SKIP102
ABE9 SKIP103
ABEB SKIP104
ABFA SKIP105
ABFC LOOP039
AC08 SKIP106
AC0A SKIP107
AC31 SKIP108
AC32 SKIP109
AC4F SKIP110
AC6B INITEXPL
AC73 LOOP040
ACAF COPYPOSVEC
ACC1 COPYPOSXY
ACE5 SKIP111
ACE6 DOCKING
ACF3 SKIP112
AD12 SKIP113
AD26 SKIP114
AD35 SKIP115
AD61 SKIP116
AD6C SKIP117
AD70 SKIP118
AD71 SKIP119
AD82 SKIP120
ADB8 SKIP121
ADB9 SKIP122
ADCA LOOP041
ADD7 LOOP042
ADF1 MODDLST
ADF4 LOOP043
ADFB LOOP044
AE03 SKIP123
AE0D CLRPLAYFIELD
AE0F CLRMEM
AE1A LOOP045
AE29 TRIGGER
AE40 SKIP124
AE41 SKIP125
AE56 SKIP126
AE58 SKIP127
AE66 SKIP128
AEA8 NOISE
AEB1 SKIP129
AEB3 LOOP046
AEC9 SKIP130
AECA HOMINGVEL
AED2 SKIP131
AEDA SKIP132
AEE1 DAMAGE
AEE7 LOOP047
AF10 SKIP133
AF19 SKIP134
AF1E SKIP135
AF32 SKIP136
AF3C SKIP137
AF3D COLLISION
AF3F LOOP048
AF43 SKIP138
AF58 SKIP139
AF64 SKIP140
AF6F SKIP141
AF94 SKIP142
AFC6 SKIP143
AFD5 LOOP049
AFE7 SKIP144
AFEC LOOP050
AFF3 SKIP145
AFFD SKIP146
AFFE KEYBOARD
B011 LOOP051
B020 SKIP147
B02B SKIP148
B036 SKIP149
B040 SKIP150
B041 SKIP151
B045 SETVIEW
B056 LOOP052
B060 SKIP152
B073 SKIP153
B07B UPDSCREEN
B082 SKIP154
B096 SKIP155
B099 SKIP156
B0E6 SKIP157
B0ED SKIP158
B0FB SKIP159
B0FC SKIP160
B106 SKIP161
B10A GAMEOVER
B121 GAMEOVER2
B14A SKIP162
B15A SKIP163
B15D SKIP164
B161 SKIP165
B162 SELECTWARP
B16A SKIP166
B16B SKIP167
B173 SKIP168
B1A7 CALCWARP
B1BE SKIP169
B1C8 SKIP170
B1D3 SKIP171
B1E0 SKIP172
B1FE LOOP053
B200 LOOP054
B212 SKIP173
B216 UPDTITLE
B21E SKIP174
B21F SKIP175
B223 SETTITLE
B22E SKIP176
B234 LOOP055
B23A SKIP177
B249 SKIP178
B25F SKIP179
B268 SKIP180
B276 LOOP056
B27C SKIP181
B286 LOOP057
B2A2 SKIP182
B2A8 SKIP183
B2AB SOUND
B2C1 LOOP058
B2E1 SKIP184
B2E6 SKIP185
B2F3 SKIP186
B32B SKIP187
B337 SKIP188
B349 SKIP189
B357 SKIP190
B369 SKIP191
B397 SKIP192
B39F SKIP193
B3A6 BEEP
B3AF LOOP059
B3B9 SKIP194
B3BA INITIALIZE
B3BC LOOP060
B3CA SKIP195
B3EE LOOP061
B41B LOOP062
B441 LOOP063
B44C LOOP064
B47C SKIP196
B488 LOOP065
B492 LOOP066
B4B9 DRAWGC
B4BD LOOP067
B4C6 SKIP197
B4E4 FLUSHGAMELOOP
B4F5 SKIP198
B50F SKIP199
B511 SKIP200
B516 SKIP201
B51A SKIP202
B51C LOOP068
B527 SKIP203
B536 SKIP204
B53E SKIP205
B544 SKIP206
B54E LOOP069
B562 SKIP207
B565 SKIP208
B569 SKIP209
B56A SKIP210
B574 SKIP211
B57C LOOP070
B59A SKIP212
B5B0 SKIP213
B5BB SKIP214
B5C1 LOOP071
B5D1 LOOP072
B5DA SKIP215
B5EA LOOP073
B5EF LOOP074
B601 LOOP075
B619 SKIP216
B61C SKIP217
B61D SKIP218
B632 LOOP076
B644 SKIP219
B655 SKIP220
B662 LOOP077
B664 LOOP078
B68D SKIP221
B68F SKIP222
B698 SKIP223
B69B ROTATE
B6A4 SKIP224
B6E1 SKIP225
B6FB SCREENCOLUMN
B709 SKIP226
B717 SKIP227
B71E SCREENROW
B72E SKIP228
B73E SKIP229
B745 SKIP230
B74A SKIP231
B753 SKIP232
B75A SKIP233
B763 SKIP234
B764 INITPOSVEC
B785 SKIP235
B7A9 SKIP236
B7BE RNDINVXY
B7D7 SKIP237
B7F0 SKIP238
B7F1 ISSURROUNDED
B803 SKIP239
B804 UPDPANEL
B810 SKIP240
B812 SKIP241
B822 SKIP242
B85C SKIP243
B86F DECENERGY
B88C SKIP244
B88E SKIP245
B896 LOOP079
B8A6 SKIP246
B8A7 SHOWCOORD
B8BD SKIP247
B8CD SHOWDIGITS
B8DF PLCOLOROFFTAB
B8E4 PLSHAP1TAB
B9B1 PLSHAP2TAB
BA62 DLSTFRAG
BA6A DLSTFRAGGC
BA6D DLSTFRAGLRS
BA75 DLSTFRAGAFT
BA7D DLSTFRAGFRONT
BA8C DLSTFRAGOFFTAB
BA90 FOURCOLORPIXEL
BAB0 PIXELMASKTAB
BAB4 VELOCITYTAB
BABE KEYTAB
BAD3 DRAINRATETAB
BADD WARPENERGYTAB
BAF5 STICKINCTAB
BAF9 DRAWLINESTAB
BB3A WARPSTARXTAB
BB3E WARPSTARYTAB
BB42 PANELTXTTAB
BBA6 SECTORTYPETAB
BBAA PHRASETAB
BC2B WORDTAB
BE22 VIEWMODETAB
BE26 MSGOFFTAB
BE29 MSGBITTAB
BE2C MSGONTAB
BE2F PLSHAPOFFTAB
BE7F PLSHAPHEIGHTTAB
BECF TRACKKEYSTAB
BED1 SECTORCHARTAB
BED7 VEERMASKTAB
BEDB PLSTARBAOFFTAB
BEDD BONUSTAB
BEE9 RANKTAB
BEFC CLASSTAB
BF0C MISSIONPHRTAB
BF10 DAMAGEPROBTAB
BF14 DAMAGEPHRTAB
BF1A DESTROYPHRTAB
BF20 NOISEPATTAB
BF3E BEEPPATTAB
BF5C BEEPFRQTAB
BF6E BLIPSHAPTAB
BF73 BARRELXTAB
BF75 HITMAXZTAB
BF7D HITMINZTAB
BF85 ZYLONHOMVELTAB
BF89 ZYLONSHAPTAB
BF91 ZYLONFLPATTAB
BF99 ZYLONVELTAB
BFA9 PFCOLORTAB
BFB3 VICINITYMASKTAB
BFBB MOVEPROBTAB
BFC0 COMPASSOFFTAB
BFC9 HOMVELTAB
BFD1 PLSHAPCOLORTAB
BFDB PLSHAPBRITTAB
BFEB NOISETORPVOLTAB
BFF3 NOISETORPFRQTAB
=D000 HPOSP0
=D001 HPOSP1
=D002 HPOSP2
=D003 HPOSP3
=D004 HPOSM0
=D005 HPOSM1
=D006 HPOSM2
=D007 HPOSM3
=D008 M0PL
=D009 M1PL
=D00A M2PL
=D00B M3PL
=D00F P3PL
=D010 TRIG0
=D012 COLPM0
=D016 COLPF0
=D01B PRIOR
=D01D GRACTL
=D01E HITCLR
=D01F CONSOL
=D200 AUDF1
=D202 AUDF2
=D203 AUDC2
=D204 AUDF3
=D205 AUDC3
=D206 AUDF4
=D207 AUDC4
=D208 AUDCTL
=D209 KBCODE
=D209 STIMER
=D20A RANDOM
=D20E IRQEN
=D20F SKCTL
=D300 PORTA
=D302 PACTL
=D400 DMACTL
=D402 DLIST
=D407 PMBASE
=D409 CHBASE
=D40A WSYNC
=D40B VCOUNT
=D40E NMIEN
=E000 ROMCHARSET