Path: utzoo!utgpu!attcan!uunet!husc6!think!ames!vsi1!daver!mfgfoc!ray
From: ray@mfgfoc.UUCP (Ray Lillard)
Newsgroups: comp.sys.mac
Subject: Summary:  Instruction Cashe Questions (Mac-II)
Keywords: cashe macII
Message-ID: <388@mfgfoc.UUCP>
Date: 3 Aug 88 22:52:35 GMT
Distribution: na
Organization: FOCUS Semiconductor Sys., Sunnyvale, CA
Lines: 33


A few weeks ago I posted a request for information regarding
disabling of the instruction cashe on the Mac-II.  I had heard
the reason MacWrite and many other publicly distributed
programs didn't run was related to the instruction cashe of
the 68020.  A summary of the two responses follows:

dplatt@coherent.com  (Dave Platt of Coherent Thought Inc.) writes:
> Some programs do bomb on the II due to the fact that they use
> self-modifying code that's incompatible with the 68020 cache.
> There's a Control Panel device that can turn the cache off;
> it will help some such programs.
> MacWrite 4.5 is incompatible with the II for other reasons...
> Turning off the cache doesn't help; the program still bombs.



barrys@apple.com   (Barry J. Semo of Apple Computer, Inc.) writes:
> Hi.  I'm afraid there is little you can do to get public domain
> programs to work on a Macintosh II that don't already.
	(comments on lack of testing and rule following by
	commercial and non-commercial developers alike omitted)
> Some programs, especially that use self modifying code, will
> benefit from turning the instruction cache off.  There is a
> public domain Control Panel device called ToggleCache that
> does this.

My thanks to the above gentleman,

-- 
Raymond Y. Lillard                    FOCUS Semiconductor Systems Inc.
net: (sun!daver!mfgfoc!ray)           570 Maude Court
att: (408) 738-0600                   Sunnyvale, CA 94086  USA