Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!wuarchive!kuhub.cc.ukans.edu!markv
From: MARKV@kuhub.cc.ukans.edu (MARK GOODERUM - UNIV. OF KANSAS ACS - MARKV@UKANVAX)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Bus Latency
Message-ID: <19804@kuhub.cc.ukans.edu>
Date: 14 Dec 89 22:37:35 GMT
References: <18387@watdragon.waterloo.edu> <8691@cbmvax.UUCP>
Organization: University of Kansas Academic Computing Services
Lines: 27

> ...They could add this, but I think the better solution would be to teach
> Exec to use VBR on 68010 on up (SetCPU uses it).  I've never tried to
> remap things by changing VBR, but long ago someone told me it didn't
> work.
> 
>> This could be a problem if anything other than the CPU alters the
>> exception vector table, however.
> 
I tried this a few months ago on my 68010 Amiga 1000.  It crashed consistanly.
At first it was the UserState() bug (I didn't know about it at the time), but
even using my own stuff to get into and out of supervisor it died hard.

Using Gomf to watch low-memory, showed that these vectors are getting played
with, and the VBR is being ignored (by the OS not the CPU of course.

Along with the execption table, it would be nice if Exec would get ALL of
ExecBase out of CHIP ram.

> -- 
> Dave Haynie Commodore-Amiga (Systems Engineering) "The Crew That Never Rests"
>    {uunet|pyramid|rutgers}!cbmvax!daveh      PLINK: hazy     BIX: hazy
>                     Too much of everything is just enough
-- 
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Mark Gooderum					   Academic Computing Services
MARKV@UKANVAX.BITNET					  University of Kansas
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