10 ; KEYCOMM.ASM›20 ; BY PAUL DRIVER›30 ; ANTIC MAGAZINE›40 ATRACT =  $4D›50 VKEYBD =  $0208›60 SRTIMR =  $022B›70 COLBAK =  $02C8›80 INITAD =  $02E2›90 KEYDEL =  $02F1›0100 CH1 =   $02F2›0110 CH  =   $02FC›0120 SSFLAG = $02FF›0130 CONSOL = $D01F›0140 KBCODE = $D209›0150 SETVBV = $E45C›0160 XITVBV = $E462›0170     *=  $0600›0180 ;INITIALIZATION ROUTINE›0190 INIT LDA #PINIT/256›0200     STA $0D›0210     LDA #PINIT&255›0220     STA $0C›0230     LDA #DVINT/256›0240     STA $0B›0250     LDA #DVINT&255›0260     STA $0A›0270     LDA #60     ; turn off the›0280     STA $D302   ; cassette motor›0290     LDA #7      ; DEFERRED VBLANK›0300     LDX # >VBVRTN›0310     LDY # <VBVRTN›0320     JSR SETVBV›0330     LDA #6      ; INITIALIZE OLD›0340     STA OLD›0350     LDA #0      ; INITIALIZE LOCK›0360     STA LOCK›0370     LDA #7›0380     STA OLD›0390     LDA # <KYBDINT ;point to our›0400     STA VKEYBD  ;   keyboard›0410     LDA # >KYBDINT ;interrupt›0420     STA VKEYBD+1 ;  routine›0430     RTS ›0440 ;KEYBOARD INTERUPT HANDLER›0450 KYBDINT LDA KBCODE›0460     CMP CH1›0470     BNE PIRQ3›0480     LDA KEYDEL›0490     BNE PIRQ4›0500 PIRQ3 LDA KBCODE›0510     CMP #$9F    ;CTRL-1›0520     BNE PIRQ1›0530     LDA SSFLAG›0540     EOR #$FF›0550     STA SSFLAG›0560     BCS PIRQ4›0570 PIRQ1 ORA LOCK  ;OUR CUSTOMIZATION›0580     STA CH›0590     STA CH1›0600     LDA #3›0610     STA KEYDEL›0620     LDA #0›0630     STA ATRACT›0640 PIRQ4 LDA #$30›0650     STA SRTIMR›0660 PIRQ2 PLA ›0670     RTI ›0680 ;VERTICAL BLANK ROUTINE›0690 VBVRTN›0700     LDA CONSOL  ;get console key›0710     AND #6      ;mask SELECT/OPTION›0720     CMP OLD     ;has it changed?›0730     BEQ EXIT    ;branch if not›0740     STA OLD     ;hold new value›0750     EOR #6      ;invert bits›0760     ASL A       ;move to MSB›0770     ASL A›0780     ASL A›0790     ASL A›0800     ASL A›0810     EOR LOCK    ;toggle value›0820     STA LOCK    ;hold onto new val›0830     BEQ SKIP    ;branch if 0›0840     ORA #4      ;turn up luminance›0850 SKIP STA COLBAK›0860 EXIT LDA LOCK   ;Added for repeat›0870     ORA CH      ;feature›0880     STA CH›0890     JMP XITVBV›0900 OLD *=  *+1›0910 LOCK *= *+1›0920 PATCH LDA $0C›0930     STA PINIT+1›0940     LDA $0D›0950     STA PINIT+2›0960     LDA $0A›0970     STA DVINT+1›0980     LDA $0B›0990     STA DVINT+2›1000     JMP INIT›1010 PINIT JSR INIT›1020     JMP INIT›1030 DVINT JSR INIT›1040     JMP INIT›1050     *=  INITAD›1060     .WORD PATCH›