10 ; COLOR PALETTE INTERRUPTS¢20 ; JOHN W. FELTON¢30 ; (c) 1985, ANTIC PUBLISHING¢40 ;¢50 DRKMSK = $4E ; ATTRACT MODE REDUCED LUMINANCE MASK¢60 COLRSH = $4F ; ATTRACT MODE COLOR SHIFT MASK¢70 WSYNC = $D40A ; WAIT FOR HORIZONTAL SYNCHRONIZATION REGISTER¢80 COLPF0 = $D016 ; COLOR REGISTER FOR PLAYFIELD ZERO¢90 COLPF1 = $D017 ; COLOR REGISTER FOR PLAYFIELD ONE¢0100 COLPF2 = $D018 ; COLOR REGISTER FOR PLAYFIELD TWO¢0110 COLPF3 = $D019 ; COLOR REGISTER FOR PLAYFIELD THREE¢0120 COLOR4 = $02C8 ; BACKGROUND COLOR REGISTER SHADOW¢0130 VDSLST = $0200 ; DISPLAY LIST INTERRUPT VECTOR¢0140 SYSVBV = $E45F ; STAGE ONE VERTICAL BLANK ENTRY¢0150 SETVBV = $E45C ; SET VERTICAL BLANK VECTOR ROUTINE¢0160 CHBASE = $D409 ; CHARACTER BASE ADDRESS¢0170 .ORG $0600 ; POSITION ON PAGE SIX¢0180 COLR0 .DS 1 ; DEFINE STORAGE FOR DISPLAY COLORS¢0190 COLR1 .DS 1¢0200 COLR2 .DS 1¢0210 COLR3 .DS 1¢0220 COLR4 .DS 1¢0230 COLR5 .DS 1¢0240 COLR6 .DS 1¢0250 COLR7 .DS 1¢0260 .DS 4 ; EXTRA STORAGE¢0270 ;¢0280 ; INTERRUPT #1¢0290 ;¢0300 INT1 PHA ; PUSH ACCUMULATOR ON STACK¢0310 LDA COLOR4 ; LOAD BACKGROUND COLOR¢0320 EOR COLRSH ; PERFORM ATTRACT MODE OPERATIONS¢0330 AND DRKMSK¢0340 STA WSYNC ; WAIT FOR HORIZONTAL BLANK¢0350 STA COLPF2 ; STORE IN GR.0 BACKGROUND COLOR REGISTER¢0360 LDA COLR7 ; LOAD DISPLAY COLOR SEVEN¢0370 EOR COLRSH ; PERFORM ATTRACT MODE OPERATIONS¢0380 AND DRKMSK¢0390 STA COLPF1 ; STORE IN GR.0 LUMINANCE COLOR REGISTER¢0400 LDA # <INT2 ; LOAD ADDRESS OF NEXT¢0410 STA VDSLST ; INTERRUPT INTO THE¢0420 LDA # >INT2 ; DISPLAY LIST INTERRUPT¢0430 STA VDSLST+1 ; VECTOR¢0440 PLA ; POP ACCUMULATOR OFF OF STACK¢0450 RTI ; RETURN FROM INTERRUPT¢0460 ;¢0470 ; INTERRUPT #2¢0480 ;¢0490 INT2 PHA ; PUSH ACCUMULATOR ON STACK¢0500 LDA COLR0 ; LOAD DISPLAY COLOR ZERO¢0510 EOR COLRSH ; PERFORM ATTRACT MODE OPERATIONS¢0520 AND DRKMSK¢0530 STA WSYNC ; WAIT FOR HORIZONTAL BLANK¢0540 STA COLPF0 ; STORE IN COLOR REGISTER ZERO¢0550 LDA COLR1 ; LOAD DISPLAY COLOR ONE¢0560 EOR COLRSH ; PERFORM ATTRACT OPERATIONS¢0570 AND DRKMSK¢0580 STA COLPF1 ; STORE IN COLOR REGISTER ONE¢0590 LDA COLR2 ; LOAD DISPLAY COLOR TWO¢0600 EOR COLRSH ; PERFORM ATTRACT OPERATIONS¢0610 AND DRKMSK¢0620 STA COLPF2 ; STORE IN COLOR REGISTER TWO¢0630 LDA COLR3 ; LOAD DISPLAY COLOR 3¢0640 EOR COLRSH ; PERFORM ATTRACT MODE OPERATIONS¢0650 AND DRKMSK¢0660 STA COLPF3 ; STORE IN COLOR REGISTER THREE¢0670 LDA # <INT3 ; LOAD ADDRESS OF NEXT¢0680 STA VDSLST ; INTERRUPT INTO¢0690 LDA # >INT3 ; DISPLAY LIST INTERRUPT¢0700 STA VDSLST+1 ; VECTOR¢0710 PLA ; POP ACCUMULATOR OFF OF STACK¢0720 RTI ; RETURN FROM INTERRUPT¢0730 ;¢0740 ; INTERRUPT #3¢0750 ;¢0760 INT3 PHA ; PUSH ACCUMULATOR ON STACK¢0770 LDA COLOR4 ; LOAD BACKGROUND COLOR¢0780 EOR COLRSH ; PERFORM ATTRACT MODE OPERATIONS¢0790 AND DRKMSK¢0800 STA WSYNC ; WAIT FOR HORIZONTAL BLANK¢0810 STA COLPF2 ; STORE IN GR.0 BACKGROUND COLOR REGISTER¢0820 LDA COLR7 ; LOAD DISPLAY COLOR SEVEN¢0830 EOR COLRSH ; PERFORM ATTRACT MODE OPERATIONS¢0840 AND DRKMSK¢0850 STA COLPF1 ; STORE IN GR.0 LUMINANCE COLOR REGISTER¢0860 LDA # <INT4 ; LOAD ADDRESS OF NEXT¢0870 STA VDSLST ; INTERRUPT INTO THE¢0880 LDA # >INT4 ; DISPLAY LIST INTERRUPT¢0890 STA VDSLST+1 ; VECTOR¢0900 PLA ; POP ACCUMULATOR OFF OF STACK¢0910 RTI ; RETURN FROM INTERRUPT¢0920 ;¢0930 ; INTERRUPT #4¢0940 ;¢0950 INT4 PHA ; PUSH ACCUMULATOR ON STACK¢0960 LDA COLR4 ; LOAD DISPLAY COLOR FOUR¢0970 EOR COLRSH ; PERFORM ATTRACT MODE OPERATIONS¢0980 AND DRKMSK¢0990 STA WSYNC ; WAIT FOR HORIZONTAL BLANK¢1000 STA COLPF0 ; STORE IN COLOR REGISTER ZERO¢1010 LDA COLR5 ; LOAD DISPLAY COLOR FIVE¢1020 EOR COLRSH ; PERFORM ATTRACT OPERATIONS¢1030 AND DRKMSK¢1040 STA COLPF1 ; STORE IN COLOR REGISTER ONE¢1050 LDA COLR6 ; LOAD DISPLAY COLOR SIX¢1060 EOR COLRSH ; PERFORM ATTRACT OPERATIONS¢1070 AND DRKMSK¢1080 STA COLPF2 ; STORE IN COLOR REGISTER TWO¢1090 LDA # <INT5 ; LOAD ADDRESS OF NEXT¢1100 STA VDSLST ; INTERRUPT INTO¢1110 LDA # >INT5 ; DISPLAY LIST INTERRUPT¢1120 STA VDSLST+1 ; VECTOR¢1130 PLA ; POP ACCUMULATOR OFF OF STACK¢1140 RTI ; RETURN FROM INTERRUPT¢1150 ;¢1160 ; INTERRUPT #5¢1170 ;¢1180 INT5 PHA ; PUSH ACCUMULATOR ON STACK¢1190 LDA COLOR4 ; LOAD BACKGROUND COLOR¢1200 EOR COLRSH ; PERFORM ATTRACT MODE OPERATIONS¢1210 AND DRKMSK¢1220 STA WSYNC ; WAIT FOR HORIZONTAL BLANK¢1230 STA COLPF2 ; STORE IN GR.0 BACKGROUND COLOR REGISTER¢1240 LDA #$E0 ; LOAD MSB OF ADDRESS OF CHARACTER SET IN ROM¢1250 STA CHBASE ; STORE IN CHARACTER SET BASE POINTER¢1260 LDA COLR7 ; LOAD DISPLAY COLOR SEVEN¢1270 EOR COLRSH ; PERFORM ATTRACT MODE OPERATIONS¢1280 AND DRKMSK¢1290 STA COLPF1 ; STORE IN GR.0 LUMINANCE COLOR REGISTER¢1300 PLA ; POP ACCUMULATOR OFF OF STACK¢1310 RTI ; RETURN FROM INTERRUPT¢1320 ;¢1330 ; VERTICAL BLANK INTERRUPT¢1340 ;¢1350 VBI LDA # <INT1 ; LOAD ADDRESS OF FIRST¢1360 STA VDSLST ; INTERRUPT INTO THE¢1370 LDA # >INT1 ; DISPLAY LIST INTERRUPT¢1380 STA VDSLST+1 ; VECTOR¢1390 JMP SYSVBV ; JUMP TO OS VERTICAL BLANK ROUTINE¢1400 ;¢1410 ; SET VECTOR TO VERTICAL BLANK INTERRUPT¢1420 ;¢1430 PLA ; DISCARD NUMBER OF PARAMETERS PASSED IN BASIC CALL¢1440 LDY # <VBI ; LOAD Y WITH LSB OF INTERRUPT ADDRESS¢1450 LDX # >VBI ; LOAD X WITH MSB OF INTERRUPT ADDRESS¢1460 LDA #6 ; LOAD ACCUMULATOR WITH SIX FOR IMMEDIATE VBI¢1470 JSR SETVBV ; CALL OS ROUTINE TO SET VECTOR¢1480 RTS ; RETURN FROM SUBROUTINE¢
