;:sys36864
	;.opt oo
	*= $c000
strout	=$ab1e
tmp	=2
mask	=4
soll	=5
	lda #<r1
	ldy #>r1
	jsr strout
	lda #%1111
	jsr test
	lda #<r2
	ldy #>r2
	jsr strout
	lda #%11110000
	jsr test
	ldy #0
	ldx #4
	lda #$d8
	sty tmp
	sta tmp+1
	lda #1
d	sta (tmp),y
	iny
	bne d
	inc tmp+1
	dex
	bne d
	rts
test	sta mask
	ldy #0
	sty tmp
	lda #$d8
	sta tmp+1
	ldx #4
tes	lda #%10101010
	sta (tmp),y
	lda (tmp),y
	and mask
	cmp #%1010
	beq jaz
	cmp #%10100000
	bne raus
jaz	lda #%01010101
	sta (tmp),y
	lda (tmp),y
	and mask
	cmp #%0101
	beq joz
	cmp #%01010000
	bne raus
joz	iny
	bne tes
	inc tmp+1
	dex
	bne tes
	lda #<ra
	ldy #>ra
	bne tend
raus	lda #<rb
	ldy #>rb
tend	jmp strout
r1	.byt 13
	.byte "farbram 1 (unten): "
	brk
r2	.byt 13
	.byte "farbram 2 (oben) : "
	brk
ra	.byte "ok"
	.byt 13,0
rb	.byte "defekt"
	.byt 13,0