* PSG Sound Test By Joseph Norman
	move.b	#$90,($C00011)

	move.w	#0,d2
add:
	move.w	d2,d0
	bsr	psgfreq
	move.l	#2,d0
	bsr	delay
	add.w	#16,d2
	cmp.w	#1024,d2
	bne	add
sub:
	sub.w	#16,d2
	move.w	d2,d0
	bsr	psgfreq
	move.l	#2,d0
	bsr	delay
	tst.w	d2
	bne	sub
	move.w	#0,d2
	bra	add

psgfreq:
	move.w	d0,d1
	and.b	#$0F,d1
	add.b	#$80,d1
	move.b	d1,($C00011)
	lsr.w	#4,d0
	move.b	d0,($C00011)
	rts

* Delay for 1 ms
* Time = 1 ms * D0
delay:
	move.l	d1,-(a7)
delay1:
	move.l	#4193,d1
delay2:
	sub.l	#1,d1
	bne	delay2
	sub.l	#1,d0
	bne	delay1
	move.l	(a7)+,d1
	rts

	END