mirror of https://github.com/a2-4am/anti-m.git
43 lines
827 B
Plaintext
43 lines
827 B
Plaintext
; Sensible Software tracer
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; written by qkumba
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;
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; tested on
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; - Sensible Speller
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;
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IDSensible
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lda #3
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ldx #1
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ldy #6
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jsr CompareMemory
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!byte $29,$00 ;AND #$00
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!byte $85,$3A ;STA $3A
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!byte $9A ;TXS
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!byte $08 ;PHP
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bcs @exit
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; patch encoded code to regain control after it loads sectors into $400+
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lda #(<@pcallback) xor $99
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sta $03A3
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lda #(>@pcallback) xor $99
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sta $03A4
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@exit
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rts
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@pcallback
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!word @callback
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@callback
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; disable ROM checksum-failure branching
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lda $6CE
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cmp #$4C
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bne +
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lda #$60
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sta $6CE
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; and nibble check which fails occasionally
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lda #$2C
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sta $79B
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+ jmp ($0026)
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