view fib.s68 @ 478:2e4a4188cfb0

Fix DMA fill so that it does not cause observable changes to the FIFO. Get DMA copy mostly correct from an observable ffect perspective. DMA copy probably does not reflect internal implementation still given that evidence seems to suggest no FIFO usage at all.
author Mike Pavone <pavone@retrodev.com>
date Tue, 17 Sep 2013 00:11:45 -0700
parents f664eeb55cb4
children 2455662378ed f7fe240a7da6
line wrap: on
line source

    dc.l $0, start
start:
	moveq #36, d0
	bsr fib
	illegal
fib:
	cmp.l #2, d0
	blt base
	subq.l #1, d0
	move.l d0, -(a7)
	bsr fib
	move.l (a7), d1
	exg d0, d1
	move.l d1, (a7)
	subq.l #1, d0
	bsr fib
	move.l (a7)+, d1
	add.l d1, d0
	rts
base:
	moveq #1, d0
	rts