78 lines
1 KiB
Plaintext
78 lines
1 KiB
Plaintext
#include "crunched_addr.gen"
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*= $0801-2
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.word *+2 ; load address
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.byt $0b,$08,$0a,$00,$9e,$32,$30,$36,$31,0,0,0
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lda #150
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sta $dd00
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lda #59
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sta $d011
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lda #$80
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sta $d018
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lda #6
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sta $d020
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ldx #<decrunch_src
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lda #>decrunch_src
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jsr decrunch
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jsr crc9k
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ldx#50
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wdata
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bit$d011
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bpl *-3
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bit$d011
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bmi *-3
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dex
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bne wdata
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stx $d020
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jsr decrunch_next_group
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jsr crc9k
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st jmp st
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crc9k
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.(
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ldy#$40
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ldx#0
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stx crc
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hbl
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sty crcl+2
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crcl
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lda $4000,x
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jsr crc8
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inx
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bne crcl
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iny
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cpy #$64
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bne hbl
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ldy #5
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cmp #0
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beq ok
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ldy #2
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ok sty $d020
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rts
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.)
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crc8: ; h/t Greg Cook, 6502.org/source/integers/crc-more.html
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.(
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eor crc ; A contained the data
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sta crc ; XOR it with the byte
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asl ; current contents of A will become x^2 term
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bcc up1 ; if b7 = 1
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eor #$07 ; then apply polynomial with feedback
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up1 eor crc ; apply x^1
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asl ; C contains b7 ^ b6
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bcc up2
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eor #$07
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up2 eor crc ; apply unity term
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sta crc ; save result
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rts
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.)
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crc brk
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#include "../decrunch.a65"
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