init:
	move.l 4.w,a6		;execbase
	clr.l d0
	move.l #gfxname,a1
	jsr -408(a6)		;oldopenlibrary()
	move.l d0,a1
	move.l 38(a1),d4	;original copper ptr

	jsr -414(a6)		;closelibrary()

	move #$ac,d7		;start y position
	move #1,d6		;y add
	move $dff01c,d5
	move #$7fff,$dff09a	;disable all bits in INTENA

	move.l #copper,$dff080

**************************
mainloop:
wframe:
	btst #0,$dff005
	bne wframe
	cmp.b #$2c,$dff006
	bne wframe
	move.w #$000,$dff180
	
;-----frame loop start---

	add d6,d7		;add "1" to y position

	cmp #$f0,d7		;bottom check
	blo ok1
	neg d6			;change direction
ok1:

	cmp.b #$40,d7
	bhi ok2
	neg d6			;change direction
ok2:

waitras1:
	cmp.b $dff006,d7
	bne waitras1
	move.w #$fff,$dff180

waitras2:
	cmp.b $dff006,d7
	beq waitras2
	move.w #$000,$dff180

;-----frame loop end---

	btst #6,$bfe001
	bne mainloop
**************************
exit:
	move.l d4,$dff080
	or #$c000,d5
	move d5,$dff09a
	rts

gfxname:
	dc.b "graphics.library",0




	SECTION tut,DATA_C
Copper:
	dc.w $100,$0200
	dc.w $ffff,$fffe