run:
	move.w #$7FFF,$DFF096	; disable all DMA

mouse:
	move.w #$64,d1
	bsr waitraster		: wait for raster line 100
	move.w #$F00,$DFF180	; change bg color

	move.w #$64+$0A,d1
	bsr waitraster		: wait for raster line in 100+10
	move.w #$000,$DFF180	; change bg color

	btst #6,$BFE001		; is lmb prssed
	bne mouse		; 0 = pressed

end:
	move.w #$FFFF,$DFF096	; enable all DMA before back to os
	rts


waitVBI:
	move.l $DFF004,d0	; get vpos
	lsr.l #8,d0		; shift 8 to left
	and.l #$1FF,d0		; mask out the 9bits of vpos
	cmp.l #$138,d0		; are we at VBI
	bne waitVBI		; no -> wait
	rts

waitraster:			; expects line to wait for in d1.w
	move.l $DFF004,d0	; get vpos
	lsr.l #8,d0		; shift 8 to left
	and.l #$1FF,d0		; mask out the 9bits of vpos
	cmp.l d1,d0		; are we at the wanted line
	bne waitraster		; no -> wait
	rts