Mixed Mode Graphics#
General Information
Author: Karl E. Wiegers
Published: ANALOG
Mixed Mode Graphics Display#
0100 ;Mixed-Mode graphics displays 0110 ;in Atari assembly language 0120 ; 0130 ;by Karl E. Wiegers 0140 ; 0150 .OPT NO LIST 0160 ; 0170 OPEN = $03 ;equates for CIO 0180 PUTREC = $09 ;operations 0190 CLOSE = $0C 0200 DRAW = $11 0210 EOL = $9B ;carriage return 0220 ROWCRS = $54 ;cursor row 0230 COLCRS = $55 ;cursor column 0240 DINDEX = $57 ;graphics mode 0250 SAVMSC = $58 ;screen RAM area 0260 SDMCTL = $022F ;screen on/off 0270 SDLSTL = $0230 ;starting address 0280 ; of display list 0290 CRSINH = $02F0 ;disable cursor 0300 ATACHR = $02FB ;select color reg 0310 ; 0320 ;equates for IOCB #0 0330 ; 0340 ICCOM = $0342 ;command byte 0350 ICBAL = $0344 ;buffer address, 0360 ICBAH = $0345 ;low and high 0370 ICBLL = $0348 ;buffer length, 0380 ICBLH = $0349 ;low and high 0390 ICAX1 = $034A ;auxiliary byte 1 0400 ICAX2 = $034B ;auxiliary byte 2 0410 CIOV = $E456 ;CIO entry point 0420 CONSOL = $D01F ;console buttons 0430 STRGNO = $CB ;work byte I need 0440 SCRRAM = $4000 ;screen RAM start 0450 ; 0460 ;Display list starts at address 0470 ;$3F00, screen RAM at $4000 0480 ; 0490 *= $3F00 0500 DLIST 0510 .BYTE 112,112,112,70,0,$40 0520 .BYTE 6,7,7,7,7,7,7,13,13 0530 .BYTE 13,13,13,13,13,13,13 0540 .BYTE 13,13,13,13,13,13,13 0550 .BYTE 13,13,13,13,13,13,13 0560 .BYTE 13,2,2,2,2,65,0,$3F 0570 ; 0580 ;program begins here 0590 ; 0600 *= $5000 0610 ; 0620 CLD ;binary mode! 0630 LDA #0 ;zero current 0640 STA STRGNO ;text line counter 0650 TAX 0660 ; 0670 ;zero out screen RAM area 0680 ; 0690 ZERO 0700 STA SCRRAM,X ;loop goes 0710 STA SCRRAM+$0100,X ;256 times 0720 STA SCRRAM+$0200,X ;each line 0730 STA SCRRAM+$0300,X ;does one 0740 STA SCRRAM+$0400,X ;page of RAM 0750 INX 0760 BNE ZERO 0770 ; 0780 ;open screen device, "S:" 0790 ; 0800 JSR OPENSCREEN 0810 LDA #1 ;turn off cursor 0820 STA CRSINH 0830 LDA DLIST+4 ;tell ANTIC 0840 STA SAVMSC ;where to find 0850 LDA DLIST+5 ;display memory 0860 STA SAVMSC+1 0870 LDA #0 ;turn off the 0880 STA SDMCTL ;screen briefly, 0890 LDA #DLIST&255 ;tell ANTIC 0900 STA SDLSTL ;where to 0910 LDA #DLIST/256 ;find the 0920 STA SDLSTL+1 ;display list, 0930 LDA #34 ;turn screen 0940 STA SDMCTL ;back on 0950 ; 0960 ;start printing text lines 0970 ; 0980 LDA #1 ;graphics mode 1 0990 STA DINDEX 1000 JSR POSITION ;position cursor 1010 LDX #$60 ;use IOCB #6 1020 LDA #LINE1&255 ;print first 1030 STA ICBAL,X ;line of text, 1040 LDA #LINE1/256 ;in Graphics 1 1050 STA ICBAH,X ;segment 1060 JSR PRINTLINE 1070 LDA #40 ;skip ahead 40 1080 JSR ADDMEM ;bytes in RAM 1090 LDA #2 ;Graphics mode 2 1100 STA DINDEX 1110 JSR POSITION ;position cursor 1120 LDX #$60 ;use IOCB #6 1130 LDA #LINE2&255 ;print all 1140 STA ICBAL,X ;text lines 1150 LDA #LINE2/256 ;in Graphics 2 1160 STA ICBAH,X ;segment 1170 JSR PRINTLINE 1180 LDA #120 ;go up 120 bytes 1190 JSR ADDMEM ;in screen RAM to 1200 LDA #7 ;Graphics 7 1210 STA DINDEX ;segment 1220 ; 1230 ;plot 1st point of rocket ship 1240 ; 1250 LDA #60 ;set coordinates 1260 STA COLCRS ;of first point 1270 LDA #8 ;to plot for 1280 STA ROWCRS ;rocket 1290 LDX #$60 ;use IOCB #6 1300 LDA #REG1&255 ;color register 1 1310 STA ICBAL,X 1320 LDA #REG1/256 1330 STA ICBAH,X 1340 JSR PLOTPOINT 1350 ; 1360 ;routine to draw the rocket 1370 ; 1380 LDA #2 ;color register 1 1390 STA ATACHR 1400 LDY #0 1410 POINT ; loop to plot 1420 LDA XDATA,Y ;points and 1430 STA COLCRS ;connect them 1440 LDA YDATA,Y ;with lines 1450 STA ROWCRS 1460 TYA 1470 PHA 1480 JSR DRAWLINE ;drawing sub. 1490 PLA 1500 TAY 1510 INY 1520 CPY #13 ;done all 13 pts? 1530 BNE POINT ;no, loop 1540 ; 1550 ;plot points for rocket exhaust 1560 ; 1570 LDX #$60 1580 LDA #REG0&255 ;color reg. 0 1590 STA ICBAL,X 1600 LDA #REG0/256 1610 STA ICBAH,X 1620 LDY #0 1630 POINT2 ; loop to get 1640 LDA EXHAUSTX,Y ;coordinates 1650 STA COLCRS ;for points 1660 LDA EXHAUSTY,Y ;from table, 1670 STA ROWCRS 1680 TYA 1690 PHA 1700 JSR PLOTPOINT ;plotting sub. 1710 PLA 1720 TAY 1730 INY 1740 CPY #4 ;done 4 pts? 1750 BNE POINT2 ;no, loop 1760 ; 1770 ;add 960 bytes to current screen 1780 ;RAM starting point, 10*96 1790 ; 1800 LDX #10 1810 ADDEMUP 1820 LDA #96 1830 JSR ADDMEM 1840 DEX 1850 BNE ADDEMUP 1860 ; 1870 ;now in bottom segment, Gr. 0 1880 ; 1890 LDA #0 ;Graphics 0 1900 STA DINDEX 1910 JSR POSITION ;set cursor 1920 LDX #$60 ;use IOCB #6 1930 LDA #LINE3&255 ;print first 1940 STA ICBAL,X ;text line 1950 LDA #LINE3/256 ;in Graphics 0 1960 STA ICBAH,X ;segment 1970 JSR PRINTLINE 1980 JSR POSITION ;print last 1990 LDX #$60 ;text line 2000 LDA #LINE4&255 2010 STA ICBAL,X 2020 LDA #LINE4/256 2030 STA ICBAH,X 2040 JSR PRINTLINE 2050 ; 2060 ;loop until START pressed, then 2070 ;close screen & reopen so blank 2080 ; 2090 LDA #8 ;initialize 2100 STA CONSOL ;buttons 2110 EXIT 2120 LDA CONSOL ;value of 6 here 2130 CMP #6 ;means START 2140 BNE EXIT ;no? try again 2150 LDX #$60 ;close screen 2160 JSR CLOSEANY 2170 JSR OPENSCREEN ;and reopen 2180 END JMP END ;wait for reset 2190 ; 2200 ;subroutine to open the screen 2210 ; 2220 OPENSCREEN 2230 LDX #$60 ;use IOCB #6 2240 LDA #OPEN ;command is OPEN 2250 STA ICCOM,X 2260 LDA #SCREEN&255 ;device to open 2270 STA ICBAL,X 2280 LDA #SCREEN/256 2290 STA ICBAH,X 2300 LDA #12 ;no text window 2310 STA ICAX1,X 2320 LDA #0 ;graphics mode 0 2330 STA ICAX2,X 2340 JSR CIOV ;go do it 2350 RTS 2360 ; 2370 ;subroutine to close any IOCB 2380 ; 2390 CLOSEANY 2400 LDA #CLOSE ;close screen 2410 STA ICCOM,X 2420 JSR CIOV 2430 RTS 2440 ; 2450 ;subroutine to position cursor 2460 ;for next text string to write 2470 ; 2480 POSITION 2490 LDX STRGNO ;get point number 2500 LDA XPOS,X ;get x-coordinate 2510 STA COLCRS ;and store 2520 LDA YPOS,X ;get y-coordinate 2530 STA ROWCRS ;and store 2540 INC STRGNO ;ready for next 2550 RTS ;point, and exit 2560 ; 2570 ;subroutine to print line up to 2580 ;120 chars long at cursor 2590 ; 2600 PRINTLINE 2610 LDA #120 ;maximum length 2620 STA ICBLL,X ;of text string 2630 LDA #0 ;is 120 chars. 2640 STA ICBLH,X 2650 LDA #PUTREC ;operation is to 2660 STA ICCOM,X ;PUT a RECord 2670 JSR CIOV ;go do it 2680 RTS 2690 ; 2700 ;subroutine to add a constant 2710 ;(in accumulator) to current 2720 ;address for start of screen RAM 2730 ; 2740 ADDMEM 2750 CLC 2760 ADC SAVMSC ;add constant to 2770 STA SAVMSC ;low byte & save 2780 BCC NOINC ;if carry set, 2790 INC SAVMSC+1 ;increment high 2800 NOINC RTS ;byte,then exit 2810 ; 2820 ;subroutine to plot a point 2830 ;using current color register 2840 ; 2850 PLOTPOINT 2860 LDA #PUTREC 2870 STA ICCOM,X 2880 LDA #1 2890 STA ICBLL,X 2900 LDA #0 2910 STA ICBLH,X 2920 JSR CIOV 2930 RTS 2940 ; 2950 ;subroutine to draw from last 2960 ;plotted point to current one 2970 ; 2980 DRAWLINE 2990 LDX #$60 3000 LDA #DRAW 3010 STA ICCOM,X 3020 JSR CIOV 3030 RTS 3040 ; 3050 ;data values needed for opening 3060 ;screen and picking color regs. 3070 ; 3080 SCREEN .BYTE "S" 3090 REG0 .BYTE "A" 3100 REG1 .BYTE "B" 3110 ; 3120 ;tables of X- and Y-positions 3130 ;for lines to be printed 3140 ; 3150 XPOS .BYTE 3,0,5,11 3160 YPOS .BYTE 0,0,1,3 3170 ; 3180 ;text strings to print 3190 ; 3200 LINE1 3210 .BYTE "attack of the",EOL 3220 LINE2 3230 .BYTE " SUICIDAL " 3240 .BYTE " " 3250 .BYTE " ROAD-RACING " 3260 .BYTE " " 3270 .BYTE " ALIENS " 3280 .BYTE EOL 3290 LINE3 3300 .BYTE "*** Press START to" 3310 .BYTE " begin ***",EOL 3320 LINE4 3330 .BYTE "Analog" 3340 .BYTE " Productions",EOL 3350 ; 3360 ;tables of coordinates for 3370 ;drawing silly-looking rocket 3380 ; 3390 XDATA 3400 .BYTE 100,130,100,60,60,95 3410 .BYTE 68,81,60,60,95,68,81 3420 YDATA 3430 .BYTE 8,11,14,14,8,8,0,8 3440 .BYTE 8,14,14,22,14 3450 EXHAUSTX .BYTE 40,46,52,58 3460 EXHAUSTY .BYTE 11,11,11,11
