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From: "Rodney W. Grimes" <rgrimes@GndRsh.aac.dev.com>
Message-Id: <199606240144.SAA07440@GndRsh.aac.dev.com>
Subject: Re: Cyrix and AMD chips
To: jhs@FreeBSD.org
Date: Sun, 23 Jun 1996 18:44:55 -0700 (PDT)
Cc: michaelv@HeadCandy.com, stesin@elvisti.kiev.ua, hardware@FreeBSD.org,
        gj@FreeBSD.org
In-Reply-To: <199606231427.QAA14819@vector.jhs.no_domain> from "Julian H. Stacey" at "Jun 23, 96 04:27:21 pm"
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> Hi, Reference:
> > From: "Michael L. VanLoon -- HeadCandy.com" <michaelv@HeadCandy.com> 
> > Subject: Re: Cyrix and AMD chips 
> 
> > >From jhs@freebsd.org
> > ># Only certainty is: AMD chips are Not always plug compatible.
> > 
> > >	I 100% agree -- not always compatible; not to mention the fact
> > >	that early Enhanced Am486 chips were ummm... say, crap,
> > >	and non-enhanced ones generally sucked, too -- compared to Intel.
> > 
> > From "Andrew V. Stesin" <stesin@elvisti.kiev.ua>
> > I *strongly* disagree.
> 
> Not sure if you disagree with Andrew's bit or my bit, if mine:
>   A pity you aren't in Munich, I think one of those chips is still in Munich,
>   I still have those same 2 boards (I bough Gary J's off him a while ago),
>   I never bet money, but I'd have bet you an indian meal +drinks,
>   that I could reproduce the failure :-)
> 
> 
> > What vintage chips are you speaking of?
> 
> Can't remember, Ask Rod Grimes or Gary Jennejohn.

Date codes from these chips are:
    D/C: E6 9431GPF
    D/C: E6 9429GPD

So they look like mid 1994 vintage A80486DX2-66 chips.  These chips where
fully tested (ran FreeBSD make worlds) in motherboard before they where
shipped, so it is/was a MB/chip compatibility problem, and not a chip
flaw with respect to the FPU problem.  I have only heard of one other
case of this, so it is very rare and only seems to inflict boards that
where designed before the Intel DX2/66 chip.

-- 
Rod Grimes                                      rgrimes@gndrsh.aac.dev.com
Accurate Automation Company                 Reliable computers for FreeBSD