Before getting to the bad stuff (the bugs), here are some goodies about ACTION! which we would like to pass on to you:
A magazine article titled "Lights, Camera, Action!" (by Dave Plotkin) which appeared in the July 1984 issue of ANTIC featured a set of routines to facilitate writing ACTION!-based interrupt handlers.
The article gave the listings for two routines (more properly, two DEFINEs) named "SaveTemps" and "GetTemps". These routines are adequate only if no math beyond addition and subtraction is performed in the interrupt service routine. The following versions of these two routines will work properly in the more general case:
Make the following DEFINEs in your program before you declare your interrupt routine (comments may be omitted-they exist only for clarification):
DEFINE SaveTemps=[ $A2 $07 ; LDX #7 $B5 $C0 ; LOOP LDA $C0,X $48 ; PHA $B5 $A0 ; LDA $A0,X $48 ; PHA $B5 $80 ; LDA $80,X $48 ; PHA $B5 $A8 ; LDA $A8,X $48 ; PHA $CA ; DEX $10 $F1 ; BPL LOOP $A5 $D3 ; LDA $D3 $48 ; PHA ] DEFINE GetTemps=[ $68 ; PLA $85 $D3 ; STA $D3 $A2 $00 ; LDX #0 $68 ; LOOP PLA $95 $A8 ; STA $A8,X $68 ; PLA $95 $80 ; STA $80,X $68 ; PLA $95 $A0 ; STA $A0,X $68 ; PLA $95 $C0 ; STA $C0,X $E8 ; INX $E0 $08 ; CPX #8 $D0 $EF ; BNE LOOP ]"
Use these routines inside your interrupt routine as follows:
PROC InterruptRoutine() ; Local declarations, if any. BYTE a, b, c, etc. ; First line of code within ; procedure SaveTemps ... ; Your interrupt ; code goes here. GetTemps ; Last line of code ; within procedure. [$6C OldVBI] ; A special way to ; end for VBIs- see ; below.
For example, the following program will set up the routine ChangeColor as a vertical blank interrupt routine (hit the START key to exit the program):
DEFINE SaveTemps= [ $A2 $07 $B5 $C0 $48 $B5 $A0 $48 $B5 $80 $48 $B5 $A8 $48 $CA $10 $F1 $A5 $D3 $48 ] DEFINE GetTemps= [ $68 $85 $D3 $A2 $00 $68 $95 $A8 $68 $95 $80 $68 $95 $A0 $68 $95 $C0 $E8 $E0 $08 $D0 $EF ] CARD OldVBI ; Will hold previous ; contents of vertical ; blank interrupt ; vector. ; This procedure will change the background color to random values. ; The main routine will set up this code to operate during the ; deferred vertical blank interrupt. PROC ChangeColor() BYTE hue, lum SaveTemps hue = Rand( 16 ) lum = Rand( 16 ) SetColor(2,hue,lum) GetTemps [ $6C OldVBI ] ; Vertical blank ; interrupts must end ; like this ($6C is a ; 6502 indirect jump ; instruction). PROC Test() ; Main routine BYTE critic=$42, ; Critical I/O flag console=$D01F ; Console key ; hardware location CARD VBIvec=$224 ; Deferred vertical ; blank interrupt vector ; You must install a VBI routine like this: critic = 1 OldVBI = VBIvec VBIvec = ChangeColor critic = 0 ; ChangeColor is now running as the vertical blank interrupt ; routine-- since our mainline code has nothing more to do, ; we just go into a loop waiting for the START key to be ; pressed. WHILE console&1 DO OD ; Now turn off the VBI routine. critic = 1 VBIvec = OldVBI critic = 0 RETURNThis method of saving and restoring ACTION zero page variables may also be used to write BASIC machine language subroutines in ACTION! Your main ACTION routine should then have SaveTemps as the first executable line, and GetTemps as the last executable line before the RETURN statement.
The following is a list of all bugs we currently know exist in the ACTION! cartridge. We list these bugs separately from those in the RunTime library and/or the PAD disk or ToolKit, which occur in following pages. Each bug is described in detail and, when possible, bug fixes are given. Many of these bugs deal only with specific versions of ACTION!. To find out which version of ACTION! you own, type the following from the ACTION! monitor: ?$B000 RETURN Below is an actual copy of what printed following that command for one of our cartridges. 45055,$B000 = 0 $0730 48 1840 ^ To find out the version number, look at the character to the right of the equals sign (here printed with a caret under it). The "0" in this case implies that the cartridge is version 3.0. If yours has a "6", you own version 3.6, etc. As of the date of this bug sheet, the current cartridge version is 3.6.
; Beginning of program -- ; First, declare TYPEs TYPE IOCB = [ BYTE Id, Devnum, Command, Status ] ; Then, if desired, ; change offset SET $B5 = $1000 ; example: offset=4096
t = a(i) ; t is an INTEGER ... ELSEIF t=0 THEN ...This works properly.
X Close( 1 ) [RETURN]You can then erase the file which caused the error.
7. TYPE POINTER ARGUMENTS PROC/FUNC declarations with record pointer arguments other than the first don't compile correctly. For example, the following code generates an error 7 (invalid argument list): TYPE REC=... ... PROC Test( BYTE x, REC POINTER p )
Affects: All versions Fix: Omit the comma in the argument list for the PROC/FUNC, as in: PROC Test( BYTE x REC POINTER p )
As this is just a temporary fix, it may not work in future versions, but the correct declaration (with the comma) will.
8. MONITOR LOCKUP Typing the following command from the monitor will lock up the system: R* RETURN
Affects: All versions Fix: Don't do it! If you do type that command, hit RESET
9. PADDLE FUNCTION The Paddle function does not work properly in all versions of the ACTION! cartridge. Affects: Versions 3.0 to 3.5 Fix: Make the following declaration in your program: BYTE ARRAY Paddle(4) = 624
10. SOUND ON CHANNELS 3 AND 4 If you use a Sound() procedure call after having done any disk I/O, sound channels 3 and 4 will remain silent. This is because Atari's OS does not reset some of the serial control registers completely. Affects: Versions 3.0 to 3.5 Fix: Type in and use the following procedure. You should call this before doing any Sound() calls and/or in place of any SndRst() calls: ; Contributed by Michael Ross PROC SoundOff() BYTE AudCtl = $D208, SSKCtl = $232, SKCtl = $D20F SSKCtl = 3 SKCtl = 3 AudCtl = 0 SndRst() RETURN
11. TYPE FIELDS AS PARAMETERS Using fields of TYPEs as parameters to PROCs or FUNCs generates incorrect code. For example, MoveBlock( rec.addr1, rec.addr2, length ) Affects: Versions 3.0 to 3.5 Fix: Assign the TYPE field to a temporary variable and pass that as a parameter: temp1 = rec.addr1 temp2 = rec.addr2 MoveBlock(temp1,temp2,length)
12. SASSIGN PROBLEMS SAssign does not work properly when the source string has a length of zero. Affects: Versions 3.0 to 3.5 Fix: No fix available at this time.
13. CARD FIELDS IN TYPES Accessing CARD fields of TYPEs generates incorrect code. Affects: Versions 3.0 to 3.2 Fix: No fix available at this time.
14. MOVEBLOCK PROBLEMS MoveBlock does not move more than 256 bytes of data. Affects: Versions 3.0 to 3.2 Fix: No fix at this time. You could write an ACTION! routine to do the equivalent.
15. CONTROL-SHIFT RETURN Using CS RETURN to split a line into two lines generates garbage in the second line. Affects: Versions 3.0 and 3.1 Fix: No fix available, but not a disastrous problem.
16. DIVISION ERRORS On old cartridges, neither the "/" operator nor the "MOD" operator works properly under certain conditions. Affects: Versions 3.0 and 3.1 Fix: Insert the following code into your program before any of your own PROCedure or FUNCtion declarations (this can be done easily using INCLUDE): ; Copyright (c) 1983 by ; Action Computer Services ; ; Permission is granted to ; duplicate and/or distribute ; the contents of this file ; to ACTION! users. Copies of ; this file may not be sold or ; used for monetary gain.
PROC RemI=*() $20 DivI $86A5 $87A6 $60
SET $4EA=DivI SET $4EC=RemI
17. ERROR ROUTINE NOT INITIALIZED The address of the Error PROCedure is not restored by ACTION! if a user program has changed it. Affects: Versions 3.0 and 3.1 Fix: Make sure to restore the original Error vector upon exiting a program, if you changed it.
18. COMPLEX EXPRESSIONS IN UNTIL Complex relational expressions in an UNTIL statement generate incorrect code. For example, DO ... UNTIL a>0 AND b=3 OD
Affects: Versions 3.0 and 3.1 Fix: Assign the expression to a temporary variable and test that variable, instead: DO ... temp = a>0 AND b=3 UNTIL temp OD
19. BANK SWITCH BUG When loading and running compiled ACTION! object files from DOS, the system can crash when using older cartridges. This is because the ACTION! library is not accessible. Affects: Version 3.0 only Fix: Put the following program lines at the VERY BEGINNING of your main procedure (i.e., the last procedure in your program): BYTE bank = $D500 ; This declares the variable ; 'bank' to reside at $D500.
bank = 0 ; This must be the ; first executable statement.
20. .COM PROGRAMS Running compiled ACTION! programs as .COM files under OS/A+ causes those programs to execute twice. Affects: All versions, but only when using a version of OS/A+. DOS XL is not affected. Fix: Insert the following as the first global variable you declare: BYTE RTS=$60 ; This MUST be the first line in your program, ; aside from comments and SET commands.
21. PROC ADDRESSING Under certain conditions, specifying the address of a procedure (e.g., to interface to a machine code routine) causes ACTION! to generate incorrect code which could cause your program to"hang". Affects: Versions 3.1 and 3.4 Fix: Insert an empty code block after the declaration of a procedure whose address is specified. For example: PROC CIO = $E456() ; An empty code block!
22. ERROR #3 If you get an ERROR 3 during a compile, the system hangs when you return to the editor. Affects: All versions Fix: Do not go to the editor until you type the following line to the monitor. This command resets the ACTION! memory pointer. SET $E=$491^
23. STRING INPUT -- When using the string input library functions (InputS, InputSD, and InputMD), there must be room in the string for the termination EOL, even though the resulting string length will not include it. Affects: All versions Fix: Adjust your declaration appropriately.