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6502 Newbie...Help Me Understand Backtracking a Value.

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MiDKnighT

Post subject: 6502 Newbie...Help Me Understand Backtracking a Value.

Posted: Sun Oct 09, 2011 2:54 pm

Joined: Sun Oct 09, 2011 2:50 pm
Posts: 6

Hi All,

I'm trying to figure out how this code came up with the value in bold. Any thoughts? Scroll down to the end to see the bolded value.

$CFCC:B1 F3 LDA ($F3),Y @ $B8F4 = #$00 A:00 X:01 Y:0A P:nVUbdIZc
$CFCE:A9 02 LDA #$02 A:00 X:01 Y:0A P:nVUbdIZc
$CFD0:85 F1 STA $00F1 = #$FF A:02 X:01 Y:0A P:nVUbdIzc
$CFD2:B1 F3 LDA ($F3),Y @ $B8F4 = #$00 A:02 X:01 Y:0A P:nVUbdIzc
$CFD4:10 04 BPL $CFDA A:00 X:01 Y:0A P:nVUbdIZc
$CFDA:85 15 STA $0015 = #$0A A:00 X:01 Y:0A P:nVUbdIZc
$CFDC:A9 00 LDA #$00 A:00 X:01 Y:0A P:nVUbdIZc
$CFDE:85 11 STA $0011 = #$08 A:00 X:01 Y:0A P:nVUbdIZc
$CFE0:A9 60 LDA #$60 A:00 X:01 Y:0A P:nVUbdIZc
$CFE2:85 12 STA $0012 = #$00 A:60 X:01 Y:0A P:nVUbdIzc
$CFE4:85 10 STA $0010 = #$CA A:60 X:01 Y:0A P:nVUbdIzc
$CFE6:20 5B C1 JSR $C15B A:60 X:01 Y:0A P:nVUbdIzc
$C15B:A9 00 LDA #$00 A:60 X:01 Y:0A P:nVUbdIzc
$C15D:85 14 STA $0014 = #$00 A:00 X:01 Y:0A P:nVUbdIZc
$C15F:A9 00 LDA #$00 A:00 X:01 Y:0A P:nVUbdIZc
$C161:85 12 STA $0012 = #$60 A:00 X:01 Y:0A P:nVUbdIZc
$C163:A5 16 LDA $0016 = #$E8 A:00 X:01 Y:0A P:nVUbdIZc
$C165:48 PHA A:E8 X:01 Y:0A P:NVUbdIzc
$C166:A5 12 LDA $0012 = #$00 A:E8 X:01 Y:0A P:NVUbdIzc
$C168:85 16 STA $0016 = #$E8 A:00 X:01 Y:0A P:nVUbdIZc
$C16A:A5 11 LDA $0011 = #$00 A:00 X:01 Y:0A P:nVUbdIZc
$C16C:85 13 STA $0013 = #$00 A:00 X:01 Y:0A P:nVUbdIZc
$C16E:A5 10 LDA $0010 = #$60 A:00 X:01 Y:0A P:nVUbdIZc
$C170:85 12 STA $0012 = #$00 A:60 X:01 Y:0A P:nVUbdIzc
$C172:98 TYA A:60 X:01 Y:0A P:nVUbdIzc
$C173:48 PHA A:0A X:01 Y:0A P:nVUbdIzc
$C174:A9 00 LDA #$00 A:0A X:01 Y:0A P:nVUbdIzc
$C176:85 10 STA $0010 = #$60 A:00 X:01 Y:0A P:nVUbdIZc
$C178:85 11 STA $0011 = #$00 A:00 X:01 Y:0A P:nVUbdIZc
$C17A:A0 18 LDY #$18 A:00 X:01 Y:0A P:nVUbdIZc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:18 P:nVUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:18 P:nVUbdIZc
$C180:26 12 ROL $0012 = #$60 A:00 X:01 Y:18 P:nVUbdIZc
$C182:26 13 ROL $0013 = #$00 A:00 X:01 Y:18 P:NVUbdIzc
$C184:26 16 ROL $0016 = #$00 A:00 X:01 Y:18 P:nVUbdIZc
$C186:90 11 BCC $C199 A:00 X:01 Y:18 P:nVUbdIZc
$C199:88 DEY A:00 X:01 Y:18 P:nVUbdIZc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:17 P:nVUbdIzc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:17 P:nVUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:17 P:nVUbdIZc
$C180:26 12 ROL $0012 = #$C0 A:00 X:01 Y:17 P:nVUbdIZc
$C182:26 13 ROL $0013 = #$00 A:00 X:01 Y:17 P:NVUbdIzC
$C184:26 16 ROL $0016 = #$00 A:00 X:01 Y:17 P:nVUbdIzc
$C186:90 11 BCC $C199 A:00 X:01 Y:17 P:nVUbdIZc
$C199:88 DEY A:00 X:01 Y:17 P:nVUbdIZc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:16 P:nVUbdIzc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:16 P:nVUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:16 P:nVUbdIZc
$C180:26 12 ROL $0012 = #$80 A:00 X:01 Y:16 P:nVUbdIZc
$C182:26 13 ROL $0013 = #$01 A:00 X:01 Y:16 P:nVUbdIZC
$C184:26 16 ROL $0016 = #$00 A:00 X:01 Y:16 P:nVUbdIzc
$C186:90 11 BCC $C199 A:00 X:01 Y:16 P:nVUbdIZc
$C199:88 DEY A:00 X:01 Y:16 P:nVUbdIZc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:15 P:nVUbdIzc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:15 P:nVUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:15 P:nVUbdIZc
$C180:26 12 ROL $0012 = #$00 A:00 X:01 Y:15 P:nVUbdIZc
$C182:26 13 ROL $0013 = #$03 A:00 X:01 Y:15 P:nVUbdIZc
$C184:26 16 ROL $0016 = #$00 A:00 X:01 Y:15 P:nVUbdIzc
$C186:90 11 BCC $C199 A:00 X:01 Y:15 P:nVUbdIZc
$C199:88 DEY A:00 X:01 Y:15 P:nVUbdIZc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:14 P:nVUbdIzc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:14 P:nVUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:14 P:nVUbdIZc
$C180:26 12 ROL $0012 = #$00 A:00 X:01 Y:14 P:nVUbdIZc
$C182:26 13 ROL $0013 = #$06 A:00 X:01 Y:14 P:nVUbdIZc
$C184:26 16 ROL $0016 = #$00 A:00 X:01 Y:14 P:nVUbdIzc
$C186:90 11 BCC $C199 A:00 X:01 Y:14 P:nVUbdIZc
$C199:88 DEY A:00 X:01 Y:14 P:nVUbdIZc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:13 P:nVUbdIzc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:13 P:nVUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:13 P:nVUbdIZc
$C180:26 12 ROL $0012 = #$00 A:00 X:01 Y:13 P:nVUbdIZc
$C182:26 13 ROL $0013 = #$0C A:00 X:01 Y:13 P:nVUbdIZc
$C184:26 16 ROL $0016 = #$00 A:00 X:01 Y:13 P:nVUbdIzc
$C186:90 11 BCC $C199 A:00 X:01 Y:13 P:nVUbdIZc
$C199:88 DEY A:00 X:01 Y:13 P:nVUbdIZc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:12 P:nVUbdIzc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:12 P:nVUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:12 P:nVUbdIZc
$C180:26 12 ROL $0012 = #$00 A:00 X:01 Y:12 P:nVUbdIZc
$C182:26 13 ROL $0013 = #$18 A:00 X:01 Y:12 P:nVUbdIZc
$C184:26 16 ROL $0016 = #$00 A:00 X:01 Y:12 P:nVUbdIzc
$C186:90 11 BCC $C199 A:00 X:01 Y:12 P:nVUbdIZc
$C199:88 DEY A:00 X:01 Y:12 P:nVUbdIZc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:11 P:nVUbdIzc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:11 P:nVUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:11 P:nVUbdIZc
$C180:26 12 ROL $0012 = #$00 A:00 X:01 Y:11 P:nVUbdIZc
$C182:26 13 ROL $0013 = #$30 A:00 X:01 Y:11 P:nVUbdIZc
$C184:26 16 ROL $0016 = #$00 A:00 X:01 Y:11 P:nVUbdIzc
$C186:90 11 BCC $C199 A:00 X:01 Y:11 P:nVUbdIZc
$C199:88 DEY A:00 X:01 Y:11 P:nVUbdIZc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:10 P:nVUbdIzc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:10 P:nVUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:10 P:nVUbdIZc
$C180:26 12 ROL $0012 = #$00 A:00 X:01 Y:10 P:nVUbdIZc
$C182:26 13 ROL $0013 = #$60 A:00 X:01 Y:10 P:nVUbdIZc
$C184:26 16 ROL $0016 = #$00 A:00 X:01 Y:10 P:NVUbdIzc
$C186:90 11 BCC $C199 A:00 X:01 Y:10 P:nVUbdIZc
$C199:88 DEY A:00 X:01 Y:10 P:nVUbdIZc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:0F P:nVUbdIzc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:0F P:nVUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:0F P:nVUbdIZc
$C180:26 12 ROL $0012 = #$00 A:00 X:01 Y:0F P:nVUbdIZc
$C182:26 13 ROL $0013 = #$C0 A:00 X:01 Y:0F P:nVUbdIZc
$C184:26 16 ROL $0016 = #$00 A:00 X:01 Y:0F P:NVUbdIzC
$C186:90 11 BCC $C199 A:00 X:01 Y:0F P:nVUbdIzc
$C199:88 DEY A:00 X:01 Y:0F P:nVUbdIzc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:0E P:nVUbdIzc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:0E P:nVUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:0E P:nVUbdIZc
$C180:26 12 ROL $0012 = #$00 A:00 X:01 Y:0E P:nVUbdIZc
$C182:26 13 ROL $0013 = #$80 A:00 X:01 Y:0E P:nVUbdIZc
$C184:26 16 ROL $0016 = #$01 A:00 X:01 Y:0E P:nVUbdIZC
$C186:90 11 BCC $C199 A:00 X:01 Y:0E P:nVUbdIzc
$C199:88 DEY A:00 X:01 Y:0E P:nVUbdIzc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:0D P:nVUbdIzc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:0D P:nVUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:0D P:nVUbdIZc
$C180:26 12 ROL $0012 = #$00 A:00 X:01 Y:0D P:nVUbdIZc
$C182:26 13 ROL $0013 = #$00 A:00 X:01 Y:0D P:nVUbdIZc
$C184:26 16 ROL $0016 = #$03 A:00 X:01 Y:0D P:nVUbdIZc
$C186:90 11 BCC $C199 A:00 X:01 Y:0D P:nVUbdIzc
$C199:88 DEY A:00 X:01 Y:0D P:nVUbdIzc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:0C P:nVUbdIzc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:0C P:nVUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:0C P:nVUbdIZc
$C180:26 12 ROL $0012 = #$00 A:00 X:01 Y:0C P:nVUbdIZc
$C182:26 13 ROL $0013 = #$00 A:00 X:01 Y:0C P:nVUbdIZc
$C184:26 16 ROL $0016 = #$06 A:00 X:01 Y:0C P:nVUbdIZc
$C186:90 11 BCC $C199 A:00 X:01 Y:0C P:nVUbdIzc
$C199:88 DEY A:00 X:01 Y:0C P:nVUbdIzc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:0B P:nVUbdIzc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:0B P:nVUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:0B P:nVUbdIZc
$C180:26 12 ROL $0012 = #$00 A:00 X:01 Y:0B P:nVUbdIZc
$C182:26 13 ROL $0013 = #$00 A:00 X:01 Y:0B P:nVUbdIZc
$C184:26 16 ROL $0016 = #$0C A:00 X:01 Y:0B P:nVUbdIZc
$C186:90 11 BCC $C199 A:00 X:01 Y:0B P:nVUbdIzc
$C199:88 DEY A:00 X:01 Y:0B P:nVUbdIzc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:0A P:nVUbdIzc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:0A P:nVUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:0A P:nVUbdIZc
$C180:26 12 ROL $0012 = #$00 A:00 X:01 Y:0A P:nVUbdIZc
$C182:26 13 ROL $0013 = #$00 A:00 X:01 Y:0A P:nVUbdIZc
$C184:26 16 ROL $0016 = #$18 A:00 X:01 Y:0A P:nVUbdIZc
$C186:90 11 BCC $C199 A:00 X:01 Y:0A P:nVUbdIzc
$C199:88 DEY A:00 X:01 Y:0A P:nVUbdIzc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:09 P:nVUbdIzc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:09 P:nVUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:09 P:nVUbdIZc
$C180:26 12 ROL $0012 = #$00 A:00 X:01 Y:09 P:nVUbdIZc
$C182:26 13 ROL $0013 = #$00 A:00 X:01 Y:09 P:nVUbdIZc
$C184:26 16 ROL $0016 = #$30 A:00 X:01 Y:09 P:nVUbdIZc
$C186:90 11 BCC $C199 A:00 X:01 Y:09 P:nVUbdIzc
$C199:88 DEY A:00 X:01 Y:09 P:nVUbdIzc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:08 P:nVUbdIzc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:08 P:nVUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:08 P:nVUbdIZc
$C180:26 12 ROL $0012 = #$00 A:00 X:01 Y:08 P:nVUbdIZc
$C182:26 13 ROL $0013 = #$00 A:00 X:01 Y:08 P:nVUbdIZc
$C184:26 16 ROL $0016 = #$60 A:00 X:01 Y:08 P:nVUbdIZc
$C186:90 11 BCC $C199 A:00 X:01 Y:08 P:NVUbdIzc
$C199:88 DEY A:00 X:01 Y:08 P:NVUbdIzc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:07 P:nVUbdIzc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:07 P:nVUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:07 P:nVUbdIZc
$C180:26 12 ROL $0012 = #$00 A:00 X:01 Y:07 P:nVUbdIZc
$C182:26 13 ROL $0013 = #$00 A:00 X:01 Y:07 P:nVUbdIZc
$C184:26 16 ROL $0016 = #$C0 A:00 X:01 Y:07 P:nVUbdIZc
$C186:90 11 BCC $C199 A:00 X:01 Y:07 P:NVUbdIzC
$C188:A5 10 LDA $0010 = #$00 A:00 X:01 Y:07 P:NVUbdIzC
$C18A:18 CLC A:00 X:01 Y:07 P:nVUbdIZC
$C18B:65 14 ADC $0014 = #$00 A:00 X:01 Y:07 P:nVUbdIZc
$C18D:85 10 STA $0010 = #$00 A:00 X:01 Y:07 P:nvUbdIZc
$C18F:A5 11 LDA $0011 = #$00 A:00 X:01 Y:07 P:nvUbdIZc
$C191:65 15 ADC $0015 = #$00 A:00 X:01 Y:07 P:nvUbdIZc
$C193:85 11 STA $0011 = #$00 A:00 X:01 Y:07 P:nvUbdIZc
$C195:90 02 BCC $C199 A:00 X:01 Y:07 P:nvUbdIZc
$C199:88 DEY A:00 X:01 Y:07 P:nvUbdIZc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:06 P:nvUbdIzc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:06 P:nvUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:06 P:nvUbdIZc
$C180:26 12 ROL $0012 = #$00 A:00 X:01 Y:06 P:nvUbdIZc
$C182:26 13 ROL $0013 = #$00 A:00 X:01 Y:06 P:nvUbdIZc
$C184:26 16 ROL $0016 = #$80 A:00 X:01 Y:06 P:nvUbdIZc
$C186:90 11 BCC $C199 A:00 X:01 Y:06 P:nvUbdIZC
$C188:A5 10 LDA $0010 = #$00 A:00 X:01 Y:06 P:nvUbdIZC
$C18A:18 CLC A:00 X:01 Y:06 P:nvUbdIZC
$C18B:65 14 ADC $0014 = #$00 A:00 X:01 Y:06 P:nvUbdIZc
$C18D:85 10 STA $0010 = #$00 A:00 X:01 Y:06 P:nvUbdIZc
$C18F:A5 11 LDA $0011 = #$00 A:00 X:01 Y:06 P:nvUbdIZc
$C191:65 15 ADC $0015 = #$00 A:00 X:01 Y:06 P:nvUbdIZc
$C193:85 11 STA $0011 = #$00 A:00 X:01 Y:06 P:nvUbdIZc
$C195:90 02 BCC $C199 A:00 X:01 Y:06 P:nvUbdIZc
$C199:88 DEY A:00 X:01 Y:06 P:nvUbdIZc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:05 P:nvUbdIzc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:05 P:nvUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:05 P:nvUbdIZc
$C180:26 12 ROL $0012 = #$00 A:00 X:01 Y:05 P:nvUbdIZc
$C182:26 13 ROL $0013 = #$00 A:00 X:01 Y:05 P:nvUbdIZc
$C184:26 16 ROL $0016 = #$00 A:00 X:01 Y:05 P:nvUbdIZc
$C186:90 11 BCC $C199 A:00 X:01 Y:05 P:nvUbdIZc
$C199:88 DEY A:00 X:01 Y:05 P:nvUbdIZc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:04 P:nvUbdIzc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:04 P:nvUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:04 P:nvUbdIZc
$C180:26 12 ROL $0012 = #$00 A:00 X:01 Y:04 P:nvUbdIZc
$C182:26 13 ROL $0013 = #$00 A:00 X:01 Y:04 P:nvUbdIZc
$C184:26 16 ROL $0016 = #$00 A:00 X:01 Y:04 P:nvUbdIZc
$C186:90 11 BCC $C199 A:00 X:01 Y:04 P:nvUbdIZc
$C199:88 DEY A:00 X:01 Y:04 P:nvUbdIZc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:03 P:nvUbdIzc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:03 P:nvUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:03 P:nvUbdIZc
$C180:26 12 ROL $0012 = #$00 A:00 X:01 Y:03 P:nvUbdIZc
$C182:26 13 ROL $0013 = #$00 A:00 X:01 Y:03 P:nvUbdIZc
$C184:26 16 ROL $0016 = #$00 A:00 X:01 Y:03 P:nvUbdIZc
$C186:90 11 BCC $C199 A:00 X:01 Y:03 P:nvUbdIZc
$C199:88 DEY A:00 X:01 Y:03 P:nvUbdIZc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:02 P:nvUbdIzc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:02 P:nvUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:02 P:nvUbdIZc
$C180:26 12 ROL $0012 = #$00 A:00 X:01 Y:02 P:nvUbdIZc
$C182:26 13 ROL $0013 = #$00 A:00 X:01 Y:02 P:nvUbdIZc
$C184:26 16 ROL $0016 = #$00 A:00 X:01 Y:02 P:nvUbdIZc
$C186:90 11 BCC $C199 A:00 X:01 Y:02 P:nvUbdIZc
$C199:88 DEY A:00 X:01 Y:02 P:nvUbdIZc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:01 P:nvUbdIzc
$C17C:06 10 ASL $0010 = #$00 A:00 X:01 Y:01 P:nvUbdIzc
$C17E:26 11 ROL $0011 = #$00 A:00 X:01 Y:01 P:nvUbdIZc
$C180:26 12 ROL $0012 = #$00 A:00 X:01 Y:01 P:nvUbdIZc
$C182:26 13 ROL $0013 = #$00 A:00 X:01 Y:01 P:nvUbdIZc
$C184:26 16 ROL $0016 = #$00 A:00 X:01 Y:01 P:nvUbdIZc
$C186:90 11 BCC $C199 A:00 X:01 Y:01 P:nvUbdIZc
$C199:88 DEY A:00 X:01 Y:01 P:nvUbdIZc
$C19A:D0 E0 BNE $C17C A:00 X:01 Y:00 P:nvUbdIZc
$C19C:A5 11 LDA $0011 = #$00 A:00 X:01 Y:00 P:nvUbdIZc
$C19E:85 10 STA $0010 = #$00 A:00 X:01 Y:00 P:nvUbdIZc
$C1A0:A5 12 LDA $0012 = #$00 A:00 X:01 Y:00 P:nvUbdIZc
$C1A2:85 11 STA $0011 = #$00 A:00 X:01 Y:00 P:nvUbdIZc
$C1A4:A5 13 LDA $0013 = #$00 A:00 X:01 Y:00 P:nvUbdIZc
$C1A6:85 12 STA $0012 = #$00 A:00 X:01 Y:00 P:nvUbdIZc
$C1A8:68 PLA A:00 X:01 Y:00 P:nvUbdIZc
$C1A9:A8 TAY A:0A X:01 Y:00 P:nvUbdIzc
$C1AA:68 PLA A:0A X:01 Y:0A P:nvUbdIzc
$C1AB:85 16 STA $0016 = #$00 A:E8 X:01 Y:0A P:NvUbdIzc
$C1AD:60 RTS A:E8 X:01 Y:0A P:NvUbdIzc
$CFE9:A5 F1 LDA $00F1 = #$02 A:E8 X:01 Y:0A P:NvUbdIzc
$CFEB:20 82 C4 JSR $C482 A:02 X:01 Y:0A P:nvUbdIzc
$C482:85 44 STA $0044 = #$0C A:02 X:01 Y:0A P:nvUbdIzc
$C484:85 ED STA $00ED = #$0C A:02 X:01 Y:0A P:nvUbdIzc
$C486:A9 01 LDA #$01 A:02 X:01 Y:0A P:nvUbdIzc
$C488:85 EB STA $00EB = #$00 A:01 X:01 Y:0A P:nvUbdIzc
$C48A:A5 ED LDA $00ED = #$02 A:01 X:01 Y:0A P:nvUbdIzc
$C48C:20 B7 C4 JSR $C4B7 A:02 X:01 Y:0A P:nvUbdIzc
$C4B7:8D F9 FF STA $FFF9 = #$AC A:02 X:01 Y:0A P:nvUbdIzc
$C4BA:4A LSR A:02 X:01 Y:0A P:nvUbdIzc
$C4BB:8D F9 FF STA $FFF9 = #$AC A:01 X:01 Y:0A P:nvUbdIzc
$C4BE:4A LSR A:01 X:01 Y:0A P:nvUbdIzc
$C4BF:8D F9 FF STA $FFF9 = #$AC A:00 X:01 Y:0A P:nvUbdIZC
$C4C2:4A LSR A:00 X:01 Y:0A P:nvUbdIZC
$C4C3:8D F9 FF STA $FFF9 = #$AC A:00 X:01 Y:0A P:nvUbdIZc
$C4C6:4A LSR A:00 X:01 Y:0A P:nvUbdIZc
$C4C7:8D F9 FF STA $FFF9 = #$AC A:00 X:01 Y:0A P:nvUbdIZc
$C4CA:60 RTS A:00 X:01 Y:0A P:nvUbdIZc
$C48F:A5 EB LDA $00EB = #$01 A:00 X:01 Y:0A P:nvUbdIZc
$C491:D0 06 BNE $C499 A:01 X:01 Y:0A P:nvUbdIzc
$C499:A9 00 LDA #$00 A:01 X:01 Y:0A P:nvUbdIzc
$C49B:85 EB STA $00EB = #$01 A:00 X:01 Y:0A P:nvUbdIZc
$C49D:60 RTS A:00 X:01 Y:0A P:nvUbdIZc
$CFEE:A9 00 LDA #$00 A:00 X:01 Y:0A P:nvUbdIZc
$CFF0:18 CLC A:00 X:01 Y:0A P:nvUbdIZc
$CFF1:65 10 ADC $0010 = #$00 A:00 X:01 Y:0A P:nvUbdIZc
$CFF3:85 1C STA $001C = #$09 A:00 X:01 Y:0A P:nvUbdIZc
$CFF5:A9 88 LDA #$88 A:00 X:01 Y:0A P:nvUbdIZc
$CFF7:65 11 ADC $0011 = #$00 A:88 X:01 Y:0A P:NvUbdIzc
$CFF9:85 1D STA $001D = #$17 A:88 X:01 Y:0A P:NvUbdIzc
$CFFB:A5 F1 LDA $00F1 = #$02 A:88 X:01 Y:0A P:NvUbdIzc
$CFFD:20 82 C4 JSR $C482 A:02 X:01 Y:0A P:nvUbdIzc
$C482:85 44 STA $0044 = #$02 A:02 X:01 Y:0A P:nvUbdIzc
$C484:85 ED STA $00ED = #$02 A:02 X:01 Y:0A P:nvUbdIzc
$C486:A9 01 LDA #$01 A:02 X:01 Y:0A P:nvUbdIzc
$C488:85 EB STA $00EB = #$00 A:01 X:01 Y:0A P:nvUbdIzc
$C48A:A5 ED LDA $00ED = #$02 A:01 X:01 Y:0A P:nvUbdIzc
$C48C:20 B7 C4 JSR $C4B7 A:02 X:01 Y:0A P:nvUbdIzc
$C4B7:8D F9 FF STA $FFF9 = #$AC A:02 X:01 Y:0A P:nvUbdIzc
$C4BA:4A LSR A:02 X:01 Y:0A P:nvUbdIzc
$C4BB:8D F9 FF STA $FFF9 = #$AC A:01 X:01 Y:0A P:nvUbdIzc
$C4BE:4A LSR A:01 X:01 Y:0A P:nvUbdIzc
$C4BF:8D F9 FF STA $FFF9 = #$AC A:00 X:01 Y:0A P:nvUbdIZC
$C4C2:4A LSR A:00 X:01 Y:0A P:nvUbdIZC
$C4C3:8D F9 FF STA $FFF9 = #$AC A:00 X:01 Y:0A P:nvUbdIZc
$C4C6:4A LSR A:00 X:01 Y:0A P:nvUbdIZc
$C4C7:8D F9 FF STA $FFF9 = #$AC A:00 X:01 Y:0A P:nvUbdIZc
$C4CA:60 RTS A:00 X:01 Y:0A P:nvUbdIZc
$C48F:A5 EB LDA $00EB = #$01 A:00 X:01 Y:0A P:nvUbdIZc
$C491:D0 06 BNE $C499 A:01 X:01 Y:0A P:nvUbdIzc
$C499:A9 00 LDA #$00 A:01 X:01 Y:0A P:nvUbdIzc
$C49B:85 EB STA $00EB = #$01 A:00 X:01 Y:0A P:nvUbdIZc
$C49D:60 RTS A:00 X:01 Y:0A P:nvUbdIZc
$D000:A6 40 LDX $0040 = #$8E A:00 X:01 Y:0A P:nvUbdIZc
$D002:A5 1F LDA $001F = #$18 A:00 X:8E Y:0A P:NvUbdIzc
$D004:9D 00 04 STA $0400,X @ $048E = #$00 A:18 X:8E Y:0A P:nvUbdIzc
$D007:E8 INX A:18 X:8E Y:0A P:nvUbdIzc
$D008:A5 1E LDA $001E = #$00 A:18 X:8F Y:0A P:NvUbdIzc
$D00A:9D 00 04 STA $0400,X @ $048F = #$10 A:00 X:8F Y:0A P:nvUbdIZc
$D00D:E8 INX A:00 X:8F Y:0A P:nvUbdIZc
$D00E:A9 60 LDA #$60 A:00 X:90 Y:0A P:NvUbdIzc
$D010:9D 00 04 STA $0400,X @ $0490 = #$FF A:60 X:90 Y:0A P:nvUbdIzc
$D013:E8 INX A:60 X:90 Y:0A P:nvUbdIzc
$D014:A5 7A LDA $007A = #$00 A:60 X:91 Y:0A P:NvUbdIzc
$D016:F0 06 BEQ $D01E A:00 X:91 Y:0A P:nvUbdIZc
$D01E:A0 00 LDY #$00 A:00 X:91 Y:0A P:nvUbdIZc
$D020:B1 1C LDA ($1C),Y @ $8800 = #$3C A:00 X:91 Y:00 P:nvUbdIZc
$D022:9D 00 04 STA $0400,X @ $0491 = #$F9 A:3C X:91 Y:00 P:nvUbdIzc

I don't understand how it came up with 8800? Does anybody know?

Last edited by MiDKnighT on Sun Oct 09, 2011 7:30 pm, edited 4 times in total.

Top

8BIT

Post subject:

Posted: Sun Oct 09, 2011 3:11 pm

Joined: Fri Aug 30, 2002 9:02 pm
Posts: 1748
Location: Sacramento, CA

LDA ($1C),Y means get the value stored at $001c and $001d, consider that a 16 bit address, then add the value of y to it, and put the contents of that address in the A register.

An example: let $001c=$34 and $001d=$12. The effective address from that is $1234. The 6502 stores the least significant byte first. Now, if Y=5, the effective address is $1234 + 5, or $1239.

Location $001c must have been set to $00 and $001d must have been set to $88, either in previous code or it is the random value that the RAM powered up with. The Y register is set to $00 in the instruction just above. That is why the $8800 is referenced.

Hope that helps.

Daryl

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MiDKnighT

Post subject:

Posted: Sun Oct 09, 2011 4:04 pm

Joined: Sun Oct 09, 2011 2:50 pm
Posts: 6

You are correct! I ran it through a debugger and indeed $001C is 00 and $001D is 88.

Now have to figure out how THOSE values got set...

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Dr Jefyll

Post subject:

Posted: Sun Oct 09, 2011 4:24 pm

Joined: Fri Dec 11, 2009 3:50 pm
Posts: 3367
Location: Ontario, Canada

Welcome to the forum, MiDKnighT !

If you like, you can share some of your background with us on the Introduce yourself thread -- although so far, it seems, most of our existing members have been too busy or too shy to do so!

BTW - re: the heading "6502 Newbie...Help Me Understand...," please try if you can (in future) to name the topic in a way that's more informative, just for the convenience of anyone scanning the list.

Cheers,

Jeff

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MiDKnighT

Post subject:

Posted: Sun Oct 09, 2011 4:31 pm

Joined: Sun Oct 09, 2011 2:50 pm
Posts: 6

Thanks Jeff,

Basically just trying to backtrack some existing 6502 code to figure out what's going on.

*deleting rest of post as I have progressed further I think*

Last edited by MiDKnighT on Sun Oct 09, 2011 8:02 pm, edited 3 times in total.

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MiDKnighT

Post subject:

Posted: Sun Oct 09, 2011 4:42 pm

Joined: Sun Oct 09, 2011 2:50 pm
Posts: 6

I should also point out that this line at the top:

$CFCC:B1 F3 LDA ($F3),Y @ $B8F4 = #$00

Affects the value. (8800). When this number changes (00, 01, 02, etc...) the address that it looks up changes (8800).

What I'm trying to do is be able to control/change that lookup.

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GARTHWILSON

Post subject:

Posted: Sun Oct 09, 2011 6:59 pm

Joined: Fri Aug 30, 2002 1:09 am
Posts: 8543
Location: Southern California

Welcome midnight!

Quote:

BTW - re: the heading "6502 Newbie...Help Me Understand...," please try if you can (in future) to name the topic in a way that's more informative, just for the convenience of anyone scanning the list.

Right. Some people won't read it if the title is not more descriptive.

Also note that you can put [code] and [/code] around your section of code to keep the monospacing and keep the forum software from throwing out the spaces that keep things aligned. (I added something else here to make them show instead of letting them do their job.) Make sure the "Disable BBCode in this post" box under the window you type in is unchecked.

Top

MiDKnighT

Post subject:

Posted: Sun Oct 09, 2011 7:42 pm

Joined: Sun Oct 09, 2011 2:50 pm
Posts: 6

Thanks,

Got suggestions on a better title?

Anyways, I think I have gotten further. I'm going to show a different example for contrast. In the first example $0015 was getting loaded with "00" and it was deriving an address of "8800". The question there was how did it translate "00" into "8800".

Now using a different example where $0015 is getting loaded with "0C" and it is deriving an address of "8C80":

Code:

$CFDA:85 15 STA $0015 = #$0A A:0C X:01 Y:0A P:nVUbdIzc

Daryl was able to help me find that the address was coming from $001C and $001D. So in this case they are:

$001C = 80
$001D = 8C

These seem to be getting set here?

Code:

$CFEE:A9 00     LDA #$00                   A:00 X:01 Y:0A P:nvUbdIZc
$CFF0:18        CLC                        A:00 X:01 Y:0A P:nvUbdIZc
$CFF1:65 10     ADC $0010 = #$80           A:00 X:01 Y:0A P:nvUbdIZc
$CFF3:85 1C     STA $001C = #$0A           A:80 X:01 Y:0A P:NvUbdIzc
$CFF5:A9 88     LDA #$88                   A:80 X:01 Y:0A P:NvUbdIzc
$CFF7:65 11     ADC $0011 = #$04           A:88 X:01 Y:0A P:NvUbdIzc
$CFF9:85 1D     STA $001D = #$17           A:8C X:01 Y:0A P:NvUbdIzc
$CFFB:A5 F1     LDA $00F1 = #$02           A:8C X:01 Y:0A P:NvUbdIzc

Notice that "A" is 88 then 80, then 8C. What does the #$0A and #$17 have to do with it? Are those previous values?

Also if I'm reading the above correct it looks like I'll need to chase down $0010 and $0011 next...

Here's the whole thing from the point it loads "OC" to $0015 to the time it reads from $8C80:

Code:

$CFDA:85 15     STA $0015 = #$0A           A:0C X:01 Y:0A P:nVUbdIzc
$CFDC:A9 00     LDA #$00                   A:0C X:01 Y:0A P:nVUbdIzc
$CFDE:85 11     STA $0011 = #$07           A:00 X:01 Y:0A P:nVUbdIZc
$CFE0:A9 60     LDA #$60                   A:00 X:01 Y:0A P:nVUbdIZc
$CFE2:85 12     STA $0012 = #$00           A:60 X:01 Y:0A P:nVUbdIzc
$CFE4:85 10     STA $0010 = #$08           A:60 X:01 Y:0A P:nVUbdIzc
$CFE6:20 5B C1  JSR $C15B                  A:60 X:01 Y:0A P:nVUbdIzc
$C15B:A9 00     LDA #$00                   A:60 X:01 Y:0A P:nVUbdIzc
$C15D:85 14     STA $0014 = #$00           A:00 X:01 Y:0A P:nVUbdIZc
$C15F:A9 00     LDA #$00                   A:00 X:01 Y:0A P:nVUbdIZc
$C161:85 12     STA $0012 = #$60           A:00 X:01 Y:0A P:nVUbdIZc
$C163:A5 16     LDA $0016 = #$E8           A:00 X:01 Y:0A P:nVUbdIZc
$C165:48        PHA                        A:E8 X:01 Y:0A P:NVUbdIzc
$C166:A5 12     LDA $0012 = #$00           A:E8 X:01 Y:0A P:NVUbdIzc
$C168:85 16     STA $0016 = #$E8           A:00 X:01 Y:0A P:nVUbdIZc
$C16A:A5 11     LDA $0011 = #$00           A:00 X:01 Y:0A P:nVUbdIZc
$C16C:85 13     STA $0013 = #$00           A:00 X:01 Y:0A P:nVUbdIZc
$C16E:A5 10     LDA $0010 = #$60           A:00 X:01 Y:0A P:nVUbdIZc
$C170:85 12     STA $0012 = #$00           A:60 X:01 Y:0A P:nVUbdIzc
$C172:98        TYA                        A:60 X:01 Y:0A P:nVUbdIzc
$C173:48        PHA                        A:0A X:01 Y:0A P:nVUbdIzc
$C174:A9 00     LDA #$00                   A:0A X:01 Y:0A P:nVUbdIzc
$C176:85 10     STA $0010 = #$60           A:00 X:01 Y:0A P:nVUbdIZc
$C178:85 11     STA $0011 = #$00           A:00 X:01 Y:0A P:nVUbdIZc
$C17A:A0 18     LDY #$18                   A:00 X:01 Y:0A P:nVUbdIZc
$C17C:06 10     ASL $0010 = #$00           A:00 X:01 Y:18 P:nVUbdIzc
$C17E:26 11     ROL $0011 = #$00           A:00 X:01 Y:18 P:nVUbdIZc
$C180:26 12     ROL $0012 = #$60           A:00 X:01 Y:18 P:nVUbdIZc
$C182:26 13     ROL $0013 = #$00           A:00 X:01 Y:18 P:NVUbdIzc
$C184:26 16     ROL $0016 = #$00           A:00 X:01 Y:18 P:nVUbdIZc
$C186:90 11     BCC $C199                  A:00 X:01 Y:18 P:nVUbdIZc
$C199:88        DEY                        A:00 X:01 Y:18 P:nVUbdIZc
$C19A:D0 E0     BNE $C17C                  A:00 X:01 Y:17 P:nVUbdIzc
$C17C:06 10     ASL $0010 = #$00           A:00 X:01 Y:17 P:nVUbdIzc
$C17E:26 11     ROL $0011 = #$00           A:00 X:01 Y:17 P:nVUbdIZc
$C180:26 12     ROL $0012 = #$C0           A:00 X:01 Y:17 P:nVUbdIZc
$C182:26 13     ROL $0013 = #$00           A:00 X:01 Y:17 P:NVUbdIzC
$C184:26 16     ROL $0016 = #$00           A:00 X:01 Y:17 P:nVUbdIzc
$C186:90 11     BCC $C199                  A:00 X:01 Y:17 P:nVUbdIZc
$C199:88        DEY                        A:00 X:01 Y:17 P:nVUbdIZc
$C19A:D0 E0     BNE $C17C                  A:00 X:01 Y:16 P:nVUbdIzc
$C17C:06 10     ASL $0010 = #$00           A:00 X:01 Y:16 P:nVUbdIzc
$C17E:26 11     ROL $0011 = #$00           A:00 X:01 Y:16 P:nVUbdIZc
$C180:26 12     ROL $0012 = #$80           A:00 X:01 Y:16 P:nVUbdIZc
$C182:26 13     ROL $0013 = #$01           A:00 X:01 Y:16 P:nVUbdIZC
$C184:26 16     ROL $0016 = #$00           A:00 X:01 Y:16 P:nVUbdIzc
$C186:90 11     BCC $C199                  A:00 X:01 Y:16 P:nVUbdIZc
$C199:88        DEY                        A:00 X:01 Y:16 P:nVUbdIZc
$C19A:D0 E0     BNE $C17C                  A:00 X:01 Y:15 P:nVUbdIzc
$C17C:06 10     ASL $0010 = #$00           A:00 X:01 Y:15 P:nVUbdIzc
$C17E:26 11     ROL $0011 = #$00           A:00 X:01 Y:15 P:nVUbdIZc
$C180:26 12     ROL $0012 = #$00           A:00 X:01 Y:15 P:nVUbdIZc
$C182:26 13     ROL $0013 = #$03           A:00 X:01 Y:15 P:nVUbdIZc
$C184:26 16     ROL $0016 = #$00           A:00 X:01 Y:15 P:nVUbdIzc
$C186:90 11     BCC $C199                  A:00 X:01 Y:15 P:nVUbdIZc
$C199:88        DEY                        A:00 X:01 Y:15 P:nVUbdIZc
$C19A:D0 E0     BNE $C17C                  A:00 X:01 Y:14 P:nVUbdIzc
$C17C:06 10     ASL $0010 = #$00           A:00 X:01 Y:14 P:nVUbdIzc
$C17E:26 11     ROL $0011 = #$00           A:00 X:01 Y:14 P:nVUbdIZc
$C180:26 12     ROL $0012 = #$00           A:00 X:01 Y:14 P:nVUbdIZc
$C182:26 13     ROL $0013 = #$06           A:00 X:01 Y:14 P:nVUbdIZc
$C184:26 16     ROL $0016 = #$00           A:00 X:01 Y:14 P:nVUbdIzc
$C186:90 11     BCC $C199                  A:00 X:01 Y:14 P:nVUbdIZc
$C199:88        DEY                        A:00 X:01 Y:14 P:nVUbdIZc
$C19A:D0 E0     BNE $C17C                  A:00 X:01 Y:13 P:nVUbdIzc
$C17C:06 10     ASL $0010 = #$00           A:00 X:01 Y:13 P:nVUbdIzc
$C17E:26 11     ROL $0011 = #$00           A:00 X:01 Y:13 P:nVUbdIZc
$C180:26 12     ROL $0012 = #$00           A:00 X:01 Y:13 P:nVUbdIZc
$C182:26 13     ROL $0013 = #$0C           A:00 X:01 Y:13 P:nVUbdIZc
$C184:26 16     ROL $0016 = #$00           A:00 X:01 Y:13 P:nVUbdIzc
$C186:90 11     BCC $C199                  A:00 X:01 Y:13 P:nVUbdIZc
$C199:88        DEY                        A:00 X:01 Y:13 P:nVUbdIZc
$C19A:D0 E0     BNE $C17C                  A:00 X:01 Y:12 P:nVUbdIzc
$C17C:06 10     ASL $0010 = #$00           A:00 X:01 Y:12 P:nVUbdIzc
$C17E:26 11     ROL $0011 = #$00           A:00 X:01 Y:12 P:nVUbdIZc
$C180:26 12     ROL $0012 = #$00           A:00 X:01 Y:12 P:nVUbdIZc
$C182:26 13     ROL $0013 = #$18           A:00 X:01 Y:12 P:nVUbdIZc
$C184:26 16     ROL $0016 = #$00           A:00 X:01 Y:12 P:nVUbdIzc
$C186:90 11     BCC $C199                  A:00 X:01 Y:12 P:nVUbdIZc
$C199:88        DEY                        A:00 X:01 Y:12 P:nVUbdIZc
$C19A:D0 E0     BNE $C17C                  A:00 X:01 Y:11 P:nVUbdIzc
$C17C:06 10     ASL $0010 = #$00           A:00 X:01 Y:11 P:nVUbdIzc
$C17E:26 11     ROL $0011 = #$00           A:00 X:01 Y:11 P:nVUbdIZc
$C180:26 12     ROL $0012 = #$00           A:00 X:01 Y:11 P:nVUbdIZc
$C182:26 13     ROL $0013 = #$30           A:00 X:01 Y:11 P:nVUbdIZc
$C184:26 16     ROL $0016 = #$00           A:00 X:01 Y:11 P:nVUbdIzc
$C186:90 11     BCC $C199                  A:00 X:01 Y:11 P:nVUbdIZc
$C199:88        DEY                        A:00 X:01 Y:11 P:nVUbdIZc
$C19A:D0 E0     BNE $C17C                  A:00 X:01 Y:10 P:nVUbdIzc
$C17C:06 10     ASL $0010 = #$00           A:00 X:01 Y:10 P:nVUbdIzc
$C17E:26 11     ROL $0011 = #$00           A:00 X:01 Y:10 P:nVUbdIZc
$C180:26 12     ROL $0012 = #$00           A:00 X:01 Y:10 P:nVUbdIZc
$C182:26 13     ROL $0013 = #$60           A:00 X:01 Y:10 P:nVUbdIZc
$C184:26 16     ROL $0016 = #$00           A:00 X:01 Y:10 P:NVUbdIzc
$C186:90 11     BCC $C199                  A:00 X:01 Y:10 P:nVUbdIZc
$C199:88        DEY                        A:00 X:01 Y:10 P:nVUbdIZc
$C19A:D0 E0     BNE $C17C                  A:00 X:01 Y:0F P:nVUbdIzc
$C17C:06 10     ASL $0010 = #$00           A:00 X:01 Y:0F P:nVUbdIzc
$C17E:26 11     ROL $0011 = #$00           A:00 X:01 Y:0F P:nVUbdIZc
$C180:26 12     ROL $0012 = #$00           A:00 X:01 Y:0F P:nVUbdIZc
$C182:26 13     ROL $0013 = #$C0           A:00 X:01 Y:0F P:nVUbdIZc
$C184:26 16     ROL $0016 = #$00           A:00 X:01 Y:0F P:NVUbdIzC
$C186:90 11     BCC $C199                  A:00 X:01 Y:0F P:nVUbdIzc
$C199:88        DEY                        A:00 X:01 Y:0F P:nVUbdIzc
$C19A:D0 E0     BNE $C17C                  A:00 X:01 Y:0E P:nVUbdIzc
$C17C:06 10     ASL $0010 = #$00           A:00 X:01 Y:0E P:nVUbdIzc
$C17E:26 11     ROL $0011 = #$00           A:00 X:01 Y:0E P:nVUbdIZc
$C180:26 12     ROL $0012 = #$00           A:00 X:01 Y:0E P:nVUbdIZc
$C182:26 13     ROL $0013 = #$80           A:00 X:01 Y:0E P:nVUbdIZc
$C184:26 16     ROL $0016 = #$01           A:00 X:01 Y:0E P:nVUbdIZC
$C186:90 11     BCC $C199                  A:00 X:01 Y:0E P:nVUbdIzc
$C199:88        DEY                        A:00 X:01 Y:0E P:nVUbdIzc
$C19A:D0 E0     BNE $C17C                  A:00 X:01 Y:0D P:nVUbdIzc
$C17C:06 10     ASL $0010 = #$00           A:00 X:01 Y:0D P:nVUbdIzc
$C17E:26 11     ROL $0011 = #$00           A:00 X:01 Y:0D P:nVUbdIZc
$C180:26 12     ROL $0012 = #$00           A:00 X:01 Y:0D P:nVUbdIZc
$C182:26 13     ROL $0013 = #$00           A:00 X:01 Y:0D P:nVUbdIZc
$C184:26 16     ROL $0016 = #$03           A:00 X:01 Y:0D P:nVUbdIZc
$C186:90 11     BCC $C199                  A:00 X:01 Y:0D P:nVUbdIzc
$C199:88        DEY                        A:00 X:01 Y:0D P:nVUbdIzc
$C19A:D0 E0     BNE $C17C                  A:00 X:01 Y:0C P:nVUbdIzc
$C17C:06 10     ASL $0010 = #$00           A:00 X:01 Y:0C P:nVUbdIzc
$C17E:26 11     ROL $0011 = #$00           A:00 X:01 Y:0C P:nVUbdIZc
$C180:26 12     ROL $0012 = #$00           A:00 X:01 Y:0C P:nVUbdIZc
$C182:26 13     ROL $0013 = #$00           A:00 X:01 Y:0C P:nVUbdIZc
$C184:26 16     ROL $0016 = #$06           A:00 X:01 Y:0C P:nVUbdIZc
$C186:90 11     BCC $C199                  A:00 X:01 Y:0C P:nVUbdIzc
$C199:88        DEY                        A:00 X:01 Y:0C P:nVUbdIzc
$C19A:D0 E0     BNE $C17C                  A:00 X:01 Y:0B P:nVUbdIzc
$C17C:06 10     ASL $0010 = #$00           A:00 X:01 Y:0B P:nVUbdIzc
$C17E:26 11     ROL $0011 = #$00           A:00 X:01 Y:0B P:nVUbdIZc
$C180:26 12     ROL $0012 = #$00           A:00 X:01 Y:0B P:nVUbdIZc
$C182:26 13     ROL $0013 = #$00           A:00 X:01 Y:0B P:nVUbdIZc
$C184:26 16     ROL $0016 = #$0C           A:00 X:01 Y:0B P:nVUbdIZc
$C186:90 11     BCC $C199                  A:00 X:01 Y:0B P:nVUbdIzc
$C199:88        DEY                        A:00 X:01 Y:0B P:nVUbdIzc
$C19A:D0 E0     BNE $C17C                  A:00 X:01 Y:0A P:nVUbdIzc
$C17C:06 10     ASL $0010 = #$00           A:00 X:01 Y:0A P:nVUbdIzc
$C17E:26 11     ROL $0011 = #$00           A:00 X:01 Y:0A P:nVUbdIZc
$C180:26 12     ROL $0012 = #$00           A:00 X:01 Y:0A P:nVUbdIZc
$C182:26 13     ROL $0013 = #$00           A:00 X:01 Y:0A P:nVUbdIZc
$C184:26 16     ROL $0016 = #$18           A:00 X:01 Y:0A P:nVUbdIZc
$C186:90 11     BCC $C199                  A:00 X:01 Y:0A P:nVUbdIzc
$C199:88        DEY                        A:00 X:01 Y:0A P:nVUbdIzc
$C19A:D0 E0     BNE $C17C                  A:00 X:01 Y:09 P:nVUbdIzc
$C17C:06 10     ASL $0010 = #$00           A:00 X:01 Y:09 P:nVUbdIzc
$C17E:26 11     ROL $0011 = #$00           A:00 X:01 Y:09 P:nVUbdIZc
$C180:26 12     ROL $0012 = #$00           A:00 X:01 Y:09 P:nVUbdIZc
$C182:26 13     ROL $0013 = #$00           A:00 X:01 Y:09 P:nVUbdIZc
$C184:26 16     ROL $0016 = #$30           A:00 X:01 Y:09 P:nVUbdIZc
$C186:90 11     BCC $C199                  A:00 X:01 Y:09 P:nVUbdIzc
$C199:88        DEY                        A:00 X:01 Y:09 P:nVUbdIzc
$C19A:D0 E0     BNE $C17C                  A:00 X:01 Y:08 P:nVUbdIzc
$C17C:06 10     ASL $0010 = #$00           A:00 X:01 Y:08 P:nVUbdIzc
$C17E:26 11     ROL $0011 = #$00           A:00 X:01 Y:08 P:nVUbdIZc
$C180:26 12     ROL $0012 = #$00           A:00 X:01 Y:08 P:nVUbdIZc
$C182:26 13     ROL $0013 = #$00           A:00 X:01 Y:08 P:nVUbdIZc
$C184:26 16     ROL $0016 = #$60           A:00 X:01 Y:08 P:nVUbdIZc
$C186:90 11     BCC $C199                  A:00 X:01 Y:08 P:NVUbdIzc
$C199:88        DEY                        A:00 X:01 Y:08 P:NVUbdIzc
$C19A:D0 E0     BNE $C17C                  A:00 X:01 Y:07 P:nVUbdIzc
$C17C:06 10     ASL $0010 = #$00           A:00 X:01 Y:07 P:nVUbdIzc
$C17E:26 11     ROL $0011 = #$00           A:00 X:01 Y:07 P:nVUbdIZc
$C180:26 12     ROL $0012 = #$00           A:00 X:01 Y:07 P:nVUbdIZc
$C182:26 13     ROL $0013 = #$00           A:00 X:01 Y:07 P:nVUbdIZc
$C184:26 16     ROL $0016 = #$C0           A:00 X:01 Y:07 P:nVUbdIZc
$C186:90 11     BCC $C199                  A:00 X:01 Y:07 P:NVUbdIzC
$C188:A5 10     LDA $0010 = #$00           A:00 X:01 Y:07 P:NVUbdIzC
$C18A:18        CLC                        A:00 X:01 Y:07 P:nVUbdIZC
$C18B:65 14     ADC $0014 = #$00           A:00 X:01 Y:07 P:nVUbdIZc
$C18D:85 10     STA $0010 = #$00           A:00 X:01 Y:07 P:nvUbdIZc
$C18F:A5 11     LDA $0011 = #$00           A:00 X:01 Y:07 P:nvUbdIZc
$C191:65 15     ADC $0015 = #$0C           A:00 X:01 Y:07 P:nvUbdIZc
$C193:85 11     STA $0011 = #$00           A:0C X:01 Y:07 P:nvUbdIzc
$C195:90 02     BCC $C199                  A:0C X:01 Y:07 P:nvUbdIzc
$C199:88        DEY                        A:0C X:01 Y:07 P:nvUbdIzc
$C19A:D0 E0     BNE $C17C                  A:0C X:01 Y:06 P:nvUbdIzc
$C17C:06 10     ASL $0010 = #$00           A:0C X:01 Y:06 P:nvUbdIzc
$C17E:26 11     ROL $0011 = #$0C           A:0C X:01 Y:06 P:nvUbdIZc
$C180:26 12     ROL $0012 = #$00           A:0C X:01 Y:06 P:nvUbdIzc
$C182:26 13     ROL $0013 = #$00           A:0C X:01 Y:06 P:nvUbdIZc
$C184:26 16     ROL $0016 = #$80           A:0C X:01 Y:06 P:nvUbdIZc
$C186:90 11     BCC $C199                  A:0C X:01 Y:06 P:nvUbdIZC
$C188:A5 10     LDA $0010 = #$00           A:0C X:01 Y:06 P:nvUbdIZC
$C18A:18        CLC                        A:00 X:01 Y:06 P:nvUbdIZC
$C18B:65 14     ADC $0014 = #$00           A:00 X:01 Y:06 P:nvUbdIZc
$C18D:85 10     STA $0010 = #$00           A:00 X:01 Y:06 P:nvUbdIZc
$C18F:A5 11     LDA $0011 = #$18           A:00 X:01 Y:06 P:nvUbdIZc
$C191:65 15     ADC $0015 = #$0C           A:18 X:01 Y:06 P:nvUbdIzc
$C193:85 11     STA $0011 = #$18           A:24 X:01 Y:06 P:nvUbdIzc
$C195:90 02     BCC $C199                  A:24 X:01 Y:06 P:nvUbdIzc
$C199:88        DEY                        A:24 X:01 Y:06 P:nvUbdIzc
$C19A:D0 E0     BNE $C17C                  A:24 X:01 Y:05 P:nvUbdIzc
$C17C:06 10     ASL $0010 = #$00           A:24 X:01 Y:05 P:nvUbdIzc
$C17E:26 11     ROL $0011 = #$24           A:24 X:01 Y:05 P:nvUbdIZc
$C180:26 12     ROL $0012 = #$00           A:24 X:01 Y:05 P:nvUbdIzc
$C182:26 13     ROL $0013 = #$00           A:24 X:01 Y:05 P:nvUbdIZc
$C184:26 16     ROL $0016 = #$00           A:24 X:01 Y:05 P:nvUbdIZc
$C186:90 11     BCC $C199                  A:24 X:01 Y:05 P:nvUbdIZc
$C199:88        DEY                        A:24 X:01 Y:05 P:nvUbdIZc
$C19A:D0 E0     BNE $C17C                  A:24 X:01 Y:04 P:nvUbdIzc
$C17C:06 10     ASL $0010 = #$00           A:24 X:01 Y:04 P:nvUbdIzc
$C17E:26 11     ROL $0011 = #$48           A:24 X:01 Y:04 P:nvUbdIZc
$C180:26 12     ROL $0012 = #$00           A:24 X:01 Y:04 P:NvUbdIzc
$C182:26 13     ROL $0013 = #$00           A:24 X:01 Y:04 P:nvUbdIZc
$C184:26 16     ROL $0016 = #$00           A:24 X:01 Y:04 P:nvUbdIZc
$C186:90 11     BCC $C199                  A:24 X:01 Y:04 P:nvUbdIZc
$C199:88        DEY                        A:24 X:01 Y:04 P:nvUbdIZc
$C19A:D0 E0     BNE $C17C                  A:24 X:01 Y:03 P:nvUbdIzc
$C17C:06 10     ASL $0010 = #$00           A:24 X:01 Y:03 P:nvUbdIzc
$C17E:26 11     ROL $0011 = #$90           A:24 X:01 Y:03 P:nvUbdIZc
$C180:26 12     ROL $0012 = #$00           A:24 X:01 Y:03 P:nvUbdIzC
$C182:26 13     ROL $0013 = #$00           A:24 X:01 Y:03 P:nvUbdIzc
$C184:26 16     ROL $0016 = #$00           A:24 X:01 Y:03 P:nvUbdIZc
$C186:90 11     BCC $C199                  A:24 X:01 Y:03 P:nvUbdIZc
$C199:88        DEY                        A:24 X:01 Y:03 P:nvUbdIZc
$C19A:D0 E0     BNE $C17C                  A:24 X:01 Y:02 P:nvUbdIzc
$C17C:06 10     ASL $0010 = #$00           A:24 X:01 Y:02 P:nvUbdIzc
$C17E:26 11     ROL $0011 = #$20           A:24 X:01 Y:02 P:nvUbdIZc
$C180:26 12     ROL $0012 = #$01           A:24 X:01 Y:02 P:nvUbdIzc
$C182:26 13     ROL $0013 = #$00           A:24 X:01 Y:02 P:nvUbdIzc
$C184:26 16     ROL $0016 = #$00           A:24 X:01 Y:02 P:nvUbdIZc
$C186:90 11     BCC $C199                  A:24 X:01 Y:02 P:nvUbdIZc
$C199:88        DEY                        A:24 X:01 Y:02 P:nvUbdIZc
$C19A:D0 E0     BNE $C17C                  A:24 X:01 Y:01 P:nvUbdIzc
$C17C:06 10     ASL $0010 = #$00           A:24 X:01 Y:01 P:nvUbdIzc
$C17E:26 11     ROL $0011 = #$40           A:24 X:01 Y:01 P:nvUbdIZc
$C180:26 12     ROL $0012 = #$02           A:24 X:01 Y:01 P:NvUbdIzc
$C182:26 13     ROL $0013 = #$00           A:24 X:01 Y:01 P:nvUbdIzc
$C184:26 16     ROL $0016 = #$00           A:24 X:01 Y:01 P:nvUbdIZc
$C186:90 11     BCC $C199                  A:24 X:01 Y:01 P:nvUbdIZc
$C199:88        DEY                        A:24 X:01 Y:01 P:nvUbdIZc
$C19A:D0 E0     BNE $C17C                  A:24 X:01 Y:00 P:nvUbdIZc
$C19C:A5 11     LDA $0011 = #$80           A:24 X:01 Y:00 P:nvUbdIZc
$C19E:85 10     STA $0010 = #$00           A:80 X:01 Y:00 P:NvUbdIzc
$C1A0:A5 12     LDA $0012 = #$04           A:80 X:01 Y:00 P:NvUbdIzc
$C1A2:85 11     STA $0011 = #$80           A:04 X:01 Y:00 P:nvUbdIzc
$C1A4:A5 13     LDA $0013 = #$00           A:04 X:01 Y:00 P:nvUbdIzc
$C1A6:85 12     STA $0012 = #$04           A:00 X:01 Y:00 P:nvUbdIZc
$C1A8:68        PLA                        A:00 X:01 Y:00 P:nvUbdIZc
$C1A9:A8        TAY                        A:0A X:01 Y:00 P:nvUbdIzc
$C1AA:68        PLA                        A:0A X:01 Y:0A P:nvUbdIzc
$C1AB:85 16     STA $0016 = #$00           A:E8 X:01 Y:0A P:NvUbdIzc
$C1AD:60        RTS                        A:E8 X:01 Y:0A P:NvUbdIzc
$CFE9:A5 F1     LDA $00F1 = #$02           A:E8 X:01 Y:0A P:NvUbdIzc
$CFEB:20 82 C4  JSR $C482                  A:02 X:01 Y:0A P:nvUbdIzc
$C482:85 44     STA $0044 = #$0C           A:02 X:01 Y:0A P:nvUbdIzc
$C484:85 ED     STA $00ED = #$0C           A:02 X:01 Y:0A P:nvUbdIzc
$C486:A9 01     LDA #$01                   A:02 X:01 Y:0A P:nvUbdIzc
$C488:85 EB     STA $00EB = #$00           A:01 X:01 Y:0A P:nvUbdIzc
$C48A:A5 ED     LDA $00ED = #$02           A:01 X:01 Y:0A P:nvUbdIzc
$C48C:20 B7 C4  JSR $C4B7                  A:02 X:01 Y:0A P:nvUbdIzc
$C4B7:8D F9 FF  STA $FFF9 = #$AC           A:02 X:01 Y:0A P:nvUbdIzc
$C4BA:4A        LSR                        A:02 X:01 Y:0A P:nvUbdIzc
$C4BB:8D F9 FF  STA $FFF9 = #$AC           A:01 X:01 Y:0A P:nvUbdIzc
$C4BE:4A        LSR                        A:01 X:01 Y:0A P:nvUbdIzc
$C4BF:8D F9 FF  STA $FFF9 = #$AC           A:00 X:01 Y:0A P:nvUbdIZC
$C4C2:4A        LSR                        A:00 X:01 Y:0A P:nvUbdIZC
$C4C3:8D F9 FF  STA $FFF9 = #$AC           A:00 X:01 Y:0A P:nvUbdIZc
$C4C6:4A        LSR                        A:00 X:01 Y:0A P:nvUbdIZc
$C4C7:8D F9 FF  STA $FFF9 = #$AC           A:00 X:01 Y:0A P:nvUbdIZc
$C4CA:60        RTS                        A:00 X:01 Y:0A P:nvUbdIZc
$C48F:A5 EB     LDA $00EB = #$01           A:00 X:01 Y:0A P:nvUbdIZc
$C491:D0 06     BNE $C499                  A:01 X:01 Y:0A P:nvUbdIzc
$C499:A9 00     LDA #$00                   A:01 X:01 Y:0A P:nvUbdIzc
$C49B:85 EB     STA $00EB = #$01           A:00 X:01 Y:0A P:nvUbdIZc
$C49D:60        RTS                        A:00 X:01 Y:0A P:nvUbdIZc
$CFEE:A9 00     LDA #$00                   A:00 X:01 Y:0A P:nvUbdIZc
$CFF0:18        CLC                        A:00 X:01 Y:0A P:nvUbdIZc
$CFF1:65 10     ADC $0010 = #$80           A:00 X:01 Y:0A P:nvUbdIZc
$CFF3:85 1C     STA $001C = #$0A           A:80 X:01 Y:0A P:NvUbdIzc
$CFF5:A9 88     LDA #$88                   A:80 X:01 Y:0A P:NvUbdIzc
$CFF7:65 11     ADC $0011 = #$04           A:88 X:01 Y:0A P:NvUbdIzc
$CFF9:85 1D     STA $001D = #$17           A:8C X:01 Y:0A P:NvUbdIzc
$CFFB:A5 F1     LDA $00F1 = #$02           A:8C X:01 Y:0A P:NvUbdIzc
$CFFD:20 82 C4  JSR $C482                  A:02 X:01 Y:0A P:nvUbdIzc
$C482:85 44     STA $0044 = #$02           A:02 X:01 Y:0A P:nvUbdIzc
$C484:85 ED     STA $00ED = #$02           A:02 X:01 Y:0A P:nvUbdIzc
$C486:A9 01     LDA #$01                   A:02 X:01 Y:0A P:nvUbdIzc
$C488:85 EB     STA $00EB = #$00           A:01 X:01 Y:0A P:nvUbdIzc
$C48A:A5 ED     LDA $00ED = #$02           A:01 X:01 Y:0A P:nvUbdIzc
$C48C:20 B7 C4  JSR $C4B7                  A:02 X:01 Y:0A P:nvUbdIzc
$C4B7:8D F9 FF  STA $FFF9 = #$AC           A:02 X:01 Y:0A P:nvUbdIzc
$C4BA:4A        LSR                        A:02 X:01 Y:0A P:nvUbdIzc
$C4BB:8D F9 FF  STA $FFF9 = #$AC           A:01 X:01 Y:0A P:nvUbdIzc
$C4BE:4A        LSR                        A:01 X:01 Y:0A P:nvUbdIzc
$C4BF:8D F9 FF  STA $FFF9 = #$AC           A:00 X:01 Y:0A P:nvUbdIZC
$C4C2:4A        LSR                        A:00 X:01 Y:0A P:nvUbdIZC
$C4C3:8D F9 FF  STA $FFF9 = #$AC           A:00 X:01 Y:0A P:nvUbdIZc
$C4C6:4A        LSR                        A:00 X:01 Y:0A P:nvUbdIZc
$C4C7:8D F9 FF  STA $FFF9 = #$AC           A:00 X:01 Y:0A P:nvUbdIZc
$C4CA:60        RTS                        A:00 X:01 Y:0A P:nvUbdIZc
$C48F:A5 EB     LDA $00EB = #$01           A:00 X:01 Y:0A P:nvUbdIZc
$C491:D0 06     BNE $C499                  A:01 X:01 Y:0A P:nvUbdIzc
$C499:A9 00     LDA #$00                   A:01 X:01 Y:0A P:nvUbdIzc
$C49B:85 EB     STA $00EB = #$01           A:00 X:01 Y:0A P:nvUbdIZc
$C49D:60        RTS                        A:00 X:01 Y:0A P:nvUbdIZc
$D000:A6 40     LDX $0040 = #$DA           A:00 X:01 Y:0A P:nvUbdIZc
$D002:A5 1F     LDA $001F = #$18           A:00 X:DA Y:0A P:NvUbdIzc
$D004:9D 00 04  STA $0400,X @ $04DA = #$00 A:18 X:DA Y:0A P:nvUbdIzc
$D007:E8        INX                        A:18 X:DA Y:0A P:nvUbdIzc
$D008:A5 1E     LDA $001E = #$00           A:18 X:DB Y:0A P:NvUbdIzc
$D00A:9D 00 04  STA $0400,X @ $04DB = #$70 A:00 X:DB Y:0A P:nvUbdIZc
$D00D:E8        INX                        A:00 X:DB Y:0A P:nvUbdIZc
$D00E:A9 60     LDA #$60                   A:00 X:DC Y:0A P:NvUbdIzc
$D010:9D 00 04  STA $0400,X @ $04DC = #$26 A:60 X:DC Y:0A P:nvUbdIzc
$D013:E8        INX                        A:60 X:DC Y:0A P:nvUbdIzc
$D014:A5 7A     LDA $007A = #$00           A:60 X:DD Y:0A P:NvUbdIzc
$D016:F0 06     BEQ $D01E                  A:00 X:DD Y:0A P:nvUbdIZc
$D01E:A0 00     LDY #$00                   A:00 X:DD Y:0A P:nvUbdIZc
$D020:B1 1C     LDA ($1C),Y @ $8C80 = #$10 A:00 X:DD Y:00 P:nvUbdIZc

If anyone can explain in detail how $0015=0C becomes $001C=80 $001D=8C it would be much appreciated! I'm in over my head at the moment.

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MiDKnighT

Post subject:

Posted: Wed Oct 12, 2011 2:20 pm

Joined: Sun Oct 09, 2011 2:50 pm
Posts: 6

I have mostly figured it out and gotten done what I needed to. Big thanks to Daryl for pointing me in the right direction!

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