.include "crunched_addr.gen"
.import decrunch
.import decrunch_next_group

	lda #150
	sta $dd00
	lda #59
	sta $d011
	lda #$80
	sta $d018
	lda #6
	sta $d020
	ldx #<decrunch_src
	lda #>decrunch_src
	jsr decrunch
	jsr crc9k
	ldx#50
wdata:
	bit$d011
	bpl *-3
	bit$d011
	bmi *-3
	dex
	bne wdata
	stx $d020
	jsr decrunch_next_group
	jsr crc9k
st:
	jmp st



crc9k:
	ldy#$40
	ldx#0
	stx crc
hbl:
	sty crcl+2
crcl:
	lda $4000,x
	jsr crc8
	inx
	bne crcl
	iny
	cpy #$64
	bne hbl

	ldy #5
	cmp #0
	beq ok
	ldy #2
ok:
	sty $d020
	rts


crc8:  ; h/t Greg Cook, 6502.org/source/integers/crc-more.html
	eor crc         ; A contained the data
	sta crc         ; XOR it with the byte
	asl             ; current contents of A will become x^2 term
	bcc up1         ; if b7 = 1
	eor #$07        ; then apply polynomial with feedback
up1:
	eor crc         ; apply x^1
	asl             ; C contains b7 ^ b6
	bcc up2
	eor #$07
up2:
	eor crc         ; apply unity term
	sta crc         ; save result
	rts
crc:
	brk