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From: johnl@esegue.segue.boston.ma.us (John R. Levine)
Newsgroups: comp.arch
Subject: Re: 386 chip "hangs" when in protected mode and 387 in place SCO Xenix
Message-ID: <9008131759.AA16793@esegue.segue.boston.ma.us>
Date: 13 Aug 90 21:59:23 GMT
Sender: Postmaster@esegue.segue.boston.ma.us
Organization: Segue Software, Cambridge MA
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In-Reply-To: <504@lafayet.UUCP>

Executive summary: you lose.

Long version: Any 386 chip that doesn't say 386DX is subject to this problem.
Any 32 bit paging system, e.g. Xenix, Unix, OS/2 2.x can fail.  For a while,
Intel had an informal chip swap programs for system vendors, but they insist
it's too late now since fixed chips have been available for over a year.

Intel has a support phone number for the 387, which answers with a recording
that starts "We're incredibly busy now ...," even at 3:00 AM.  Among the
other things the recording tells you is the number of their fax-back machine,
which you call from a touch tone phone, and it turns around and calls your
fax machine back and sends you helpful support documents.  One of the
documents (which, of course, is in a file cabinet 300 miles from here) talks
about it and mentioned that someone has a little daughtercard that avoids the
problem.  There is a directory of documents that you can retrieve, and the
relevant one is called something like the 386 system compatibility list.
Note that even Intel motherboards have this problem, I have one and they're
not willing to do anything about it.

If you find the source of the daughtercards, or alternatively someone who
will actually sell a single 386/25 chip, I'd love to hear about it.

Regards,
John Levine, johnl@esegue.segue.boston.ma.us, {spdcc|ima|world}!esegue!johnl