[LTTP]

$02:824A 20 B3 D8    JSR $D8B3  [$00:D8B3]   A:0000 X:00E0 Y:0006 D:0000 DB:00 S:01FC P:envMXdiZc HC:028 VC:252 00

$02:DA64 A9 02       LDA #$02                A:0010 X:0045 Y:0228 D:0000 DB:02 S:01F9 P:envMxdizc HC:1138 VC:255 00
$02:DA66 E0 00 00    CPX #$0000              A:0002 X:0045 Y:0228 D:0000 DB:02 S:01F9 P:envMxdizc HC:1154 VC:255 00
$02:DA69 F0 07       BEQ $07    [$DA72]      A:0002 X:0045 Y:0228 D:0000 DB:02 S:01F9 P:envMxdizC HC:1178 VC:255 00
$02:DA6B E0 43 00    CPX #$0043              A:0002 X:0045 Y:0228 D:0000 DB:02 S:01F9 P:envMxdizC HC:1194 VC:255 00
$02:DA6E F0 02       BEQ $02    [$DA72]      A:0002 X:0045 Y:0228 D:0000 DB:02 S:01F9 P:envMxdizC HC:1218 VC:255 00
$02:DA70 A9 00       LDA #$00                A:0002 X:0045 Y:0228 D:0000 DB:02 S:01F9 P:envMxdizC HC:1234 VC:255 00
$02:DA72 85 2F       STA $2F    [$00:002F]   A:0000 X:0045 Y:0228 D:0000 DB:02 S:01F9 P:envMxdiZC HC:1250 VC:255 00
$02:DA74 BD 81 D3    LDA $D381,x[$02:D3C6]   A:0000 X:0045 Y:0228 D:0000 DB:02 S:01F9 P:envMxdiZC HC:1274 VC:255 00
$02:DA77 8D A1 0A    STA $0AA1  [$02:0AA1]   A:000F X:0045 Y:0228 D:0000 DB:02 S:01F9 P:envMxdizC HC:1306 VC:255 00

; Load song number
$02:DA7A BD 2E D8    LDA $D82E,x[$02:D873]   A:000F X:0045 Y:0228 D:0000 DB:02 S:01F9 P:envMxdizC HC:1338 VC:255 00
$02:DA7D 8D 32 01    STA $0132  [$02:0132]   A:0018 X:0045 Y:0228 D:0000 DB:02 S:01F9 P:envMxdizC HC:1370 VC:255 00

; Stop song check
$00:F40C AD 32 01    LDA $0132  [$00:0132]   A:FF01 X:00FE Y:00FF D:0000 DB:00 S:01F4 P:envMXdizC HC:1340 VC:014 00
$00:F40F C9 FF       CMP #$FF                A:FF18 X:00FE Y:00FF D:0000 DB:00 S:01F4 P:envMXdizC HC:1372 VC:014 00
$00:F411 F0 03       BEQ $03    [$F416]      A:FF18 X:00FE Y:00FF D:0000 DB:00 S:01F4 P:envMXdizc HC:020 VC:015 00
$00:F413 8D 2C 01    STA $012C  [$00:012C]   A:FF18 X:00FE Y:00FF D:0000 DB:00 S:01F4 P:envMXdizc HC:036 VC:015 00

; Do it's thing
$00:80D7 E2 30       SEP #$30                A:0000 X:0000 Y:0014 D:0000 DB:00 S:01F2 P:envmxdIZc HC:404 VC:225 00
$00:80D9 AD 10 42    LDA $4210  [$00:4210]   A:0000 X:0000 Y:0014 D:0000 DB:00 S:01F2 P:envMXdIZc HC:426 VC:225 00
$00:80DC AD 2C 01    LDA $012C  [$00:012C]   A:00C2 X:0000 Y:0014 D:0000 DB:00 S:01F2 P:eNvMXdIzc HC:456 VC:225 00
$00:80DF D0 0D       BNE $0D    [$80EE]      A:0000 X:0000 Y:0014 D:0000 DB:00 S:01F2 P:envMXdIZc HC:488 VC:225 00

$00:80E1 AD 40 21    LDA $2140  [$00:2140]   A:0000 X:0000 Y:0014 D:0000 DB:00 S:01F2 P:envMXdIZc HC:504 VC:225 00
$00:80E4 CD 33 01    CMP $0133  [$00:0133]   A:0002 X:0000 Y:0014 D:0000 DB:00 S:01F2 P:envMXdIzc HC:534 VC:225 00
$00:80E7 D0 1A       BNE $1A    [$8103]      A:0002 X:0000 Y:0014 D:0000 DB:00 S:01F2 P:envMXdIZC HC:566 VC:225 00
$00:80E9 9C 40 21    STZ $2140  [$00:2140]   A:0002 X:0000 Y:0014 D:0000 DB:00 S:01F2 P:envMXdIZC HC:582 VC:225 00
$00:80EC 80 15       BRA $15    [$8103]      A:0002 X:0000 Y:0014 D:0000 DB:00 S:01F2 P:envMXdIZC HC:612 VC:225 00

(music bit)
[00:80F3] W08 = 18   [002140]

$00:80EE CD 33 01    CMP $0133  [$00:0133]   A:00F1 X:00E4 Y:00FD D:0000 DB:00 S:01E6 P:eNvMXdIzC HC:560 VC:225 00
$00:80F1 F0 10       BEQ $10    [$8103]      A:00F1 X:00E4 Y:00FD D:0000 DB:00 S:01E6 P:eNvMXdIzC HC:592 VC:225 00
$00:80F3 8D 40 21    STA $2140  [$00:2140]   A:00F1 X:00E4 Y:00FD D:0000 DB:00 S:01E6 P:eNvMXdIzC HC:608 VC:225 00
$00:80F6 8D 33 01    STA $0133  [$00:0133]   A:00F1 X:00E4 Y:00FD D:0000 DB:00 S:01E6 P:eNvMXdIzC HC:638 VC:225 00

--------------------------------------------------------------------

[AST]

$82:8285 20 15 CF    JSR $CF15  [$80:CF15]   A:0000 X:00E0 Y:0002 D:0000 DB:80 S:01FC P:envMXdiZc HC:742 VC:253 00

$82:93B8 AD 32 01    LDA $0132  [$80:0132]   A:FF00 X:00FE Y:00FF D:0000 DB:80 S:01F8 P:envMXdiZC HC:962 VC:237 00
$82:93BB C9 FF       CMP #$FF                A:FF00 X:00FE Y:00FF D:0000 DB:80 S:01F8 P:envMXdiZC HC:988 VC:237 00
$82:93BD F0 03       BEQ $03    [$93C2]      A:FF00 X:00FE Y:00FF D:0000 DB:80 S:01F8 P:envMXdizc HC:1000 VC:237 00
$82:93BF 8D 2C 01    STA $012C  [$80:012C]   A:FF00 X:00FE Y:00FF D:0000 DB:80 S:01F8 P:envMXdizc HC:1012 VC:237 00

$80:8158 E2 30       SEP #$30                A:0000 X:0000 Y:0008 D:0000 DB:80 S:01F2 P:eNvmxdIzc HC:394 VC:225 00
$80:815A AD 10 42    LDA $4210  [$80:4210]   A:0000 X:0000 Y:0008 D:0000 DB:80 S:01F2 P:eNvMXdIzc HC:412 VC:225 00
$80:815D AD 2C 01    LDA $012C  [$80:012C]   A:00C2 X:0000 Y:0008 D:0000 DB:80 S:01F2 P:eNvMXdIzc HC:436 VC:225 00
$80:8160 D0 0D       BNE $0D    [$816F]      A:0000 X:0000 Y:0008 D:0000 DB:80 S:01F2 P:envMXdIZc HC:462 VC:225 00

problem = $012C is -always- 0 because $0132 never gets written to. No STA $0132 either.