26 bytes Fuzzy Logic by JAC! [web]

; >> 26 bytes Fuzzy Logic  <<<
; 2012-11071/02 by JAC!
; Based on http://pouet.net/prod.php?which=60648
; Hey, this is my first C64 prod.
; I had expected it to be different but I think
; TV noise is always a good starting point when
; discovering a new platform.
; Have fun understanding this one :-)
; @com.wudsn.ide.asm.hardware=C64

	opt h-

op_shx	= $9e		;SHX abs,y
op_ror	= $6e		;ROR abs
op_sta	= $85		;STA zp
ptr	= op_ror-1	;Operand re-use

	org $32c-1	;IN: <A>=0, <X>=0, <Y>=$0a, <C>=1
	.word $32d
	.byte $03	;Change only high byte in $32e: $ff2f to $032f

loop	.byte op_sta, ptr+1
	.byte a($d1d8)	;<C>=1, so $15/$8b, use mirror so opcode is CMP izy
	nop		;Cannot believe myself I put a NOP in a 32 bytes demo
	sta $d400,y	;Hi SID, how are you
	.byte op_shx,a($d3e0) ;SHX $d3e0,y, store 0 to mirrors of $d020/$d021
	adc $d012	;Hmm, VIC looks a bit random today
	sta (ptr),y
	and #$0f	;Increased memory range
	ora #$20
	bne loop