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From: sschaem@starnet.uucp (Stephan Schaem)
Newsgroups: comp.sys.amiga.programmer
Subject: Re: Correct code for turning off 020/030 caches?
Message-ID: <1991Jun8.132157.8194@starnet.uucp>
Date: 8 Jun 91 13:21:57 GMT
References: <1991Jun5.033401.27422@en.ecn.purdue.edu> <mykes.3186@amiga0.SF-Bay.ORG>
Organization: Starnet-Public Access UNIX-Los Altos,CA 415-949-3133, login:info
Lines: 33


 
 Just a qucky to turn cache off:
Check the CPU with exec	(Execbase, attflags)
if 2.x or greater use the exec function: CacheControl
Otherwise try the following...

	move.w	#$4000,($dff09a).l
	lea	NoCache(pc),a0
	lea	($80).w,a1
	move.l	(a1),-(sp)
	move.l	a0,(a1)
	trap	#0
	move.l	(sp)+,(a1)
	moveq	#0,d0
	rts

NoCache:
	movec	CACR,d0
	and.b	#$fe,d0
	movec	d0,CACR
	rte

The obove should work, I dont know any other way to do it on 1.0+.
Any comment will be apreciated.
I sugest You save the cache state and write a library with cache
function instead if working in multitasking under <2.x.
I only use a variant of the obove when I dont have the ROM loaded
using a trap library for supervisor function.

Hope this what you where looking for?

							Stephan.