C1/47A0 C2 31         REP #$31    ;16-bit index/16-bit accum
C1/47A2 8A            TXA         ;transfer X to A
C1/47A3 22 C9 16 C2   JSL $C216C9 ;jump to C2/16C9 (0x0218C9)
C1/47A7 A9 00 00      LDA #$0000  ;A = 0000
C1/47AA 60            RTS         ;the end

C2/16C9 C2 31         REP #$31    ;16-bit index/16-bit accum
C2/16CB 22 C6 AB C0   JSL $C0ABC6 ;jump to C0/ABC6 (0x00ADC6)
C2/16CF 6B            RTL         ;go back to the first part, after the jump

C0/ABC6 E2 20         SEP #$20    ;8-bit accum
C0/ABC8 A9 00         LDA #$00    ;A = 00
C0/ABCA 8F 40 21 00   STA $002140 ;A goes to the APU register
C0/ABCE C2 30         REP #$30    ;16-bit index/16-bit accum
C0/ABD0 22 20 AC C0   JSL $C0AC20 ;jump to C0/AC20 (0x00AE20)
C0/ABD4 C9 00 00      CMP #$0000  ;is A equal to 0000?
C0/ABD7 D0 F7         BNE $ABD0   ;if it isn't, go back to C0/ABD0 (0x00ADD0)
C0/ABD9 A9 FF FF      LDA #$FFFF  ;A = FFFF
C0/ABDC 8D 3B B5      STA $B53B   ;A goes to $B53B(?)
C0/ABDF 6B            RTL         ;go back to part 2, after jump

C0/AC20 E2 20         SEP #$20    ;8-bit accum
C0/AC22 AF 40 21 00   LDA $002140 ;load a byte from the APU register
C0/AC26 C2 30         REP #$30    ;16-bit index/16-bit accum
C0/AC28 29 FF 00      AND #$00FF  ;get only the first byte
C0/AC2B 6B            RTL         ;go back to part 3, after jump...