10 POKMSK =    0010›20 KBCODE =    $D209›30 VKEYBD =    $0208›40 IRQEN  =    $D20E›45 IRQST  =    IRQEN›46 VMIRQ  =    $0216›60        *=   $600›80 START  SEI  ;   DISABLE IRQS›90        LDA  VMIRQ ; REPLACE THE IRQ VECTOR›0100      STA  NBRK+1 ;WITH OUR OWN›0110      LDA  VMIRQ+1 ; ALL IRQS WILL›0120  STA  NBRK+2  GO TO NBRK›0130      LDA  #IRQ&255›0140      STA  VMIRQ›0150      LDA  #IRQ/256›0160      STA  VMIRQ+1›0170      CLI  ; ENABLE IRQS›0200      LDA  VKEYBD ; POINT KEY IRQ TO›0210      STA  JUMP+1; REP›0220      LDA  VKEYBD+1›0230      STA  JUMP+2›0240      LDA  #REP&255; VECTOR KEY IRQ›0250      STA  VKEYBD; LOW BYTE OF VECTOR›0260      LDA  #REP/256›0270      STA  VKEYBD+1›0280      RTS›0290      *=$639›0300 REP  LDA  KBCODE ; ALL KEY IRQS COME HERE›0310      AND  #$80 ; CHECK IF CONTROL HIT›0320      BEQ  JUMP ;IF NOT HIT THEN GO›0330      PLA  ; ELSE IGNORE CONTROL KEY›0340      RTI›0360 JUMP JMP  ; JUMP THIS CALLS THE OLD KEY IRQ›0375 IRQ  PHA  ; ALL IRQS COME HERE›0380      LDA  IRQST ; CHECK IF [BREAK]›0390      BPL  BREAK ; IF [BREAK] IRQ,BRANCH›0405      PLA  ; ELSE CALL OLD IRQ VECTOR›0410 NBRK JMP  NBRK ; CALL OLD IRQ VECTOR›0430 BREAK LDA  #$7F ; HERE IF [BREAK]›0440      STA  IRQST ; SHOW NO [BREAK]›0450      LDA  POKMSK›0460      STA  IRQEN›0462      PLA›0464      RTI ; RETURN AS IF NO [BREAK]›0470      *=  $02E2›0480      .WORD START›