TrackMouse	Lea	$Dff000,a6
	Move.w	Joy0Dat(a6),d0
	Lea	OldX(pc),a0
	Lea	XPos(pc),a1
	Move.b	0(a0),d1
	Move.b	d0,0(a0)
	Sub.b	d0,d1
	Ext.w	d1
	Sub.w	d1,0(a1)
	
	Lsr.w	#8,d0
	Move.b	2(a0),d1
	Move.b	d0,2(a0)
	Sub.b	d0,d1
	Ext.w	d1
	Sub.w	d1,2(a1)
	Rts
	
SetMouse	Lea	$Dff000,a6
	Move.w	Joy0Dat(a6),d0
	Lea	OldX(pc),a0
	Move.b	d0,0(a0)
	Lsr.w	#8,d0
	Move.b	d0,2(a0)
	Rts