Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!amdcad!sun!pitstop!sundc!seismo!uunet!portal!cup.portal.com!mslater
From: mslater@cup.portal.com (Michael Z Slater)
Newsgroups: comp.sys.intel
Subject: Re: 386 problems
Message-ID: <14458@cup.portal.com>
Date: 9 Feb 89 03:38:43 GMT
References: <5219@lynx.UUCP>
Distribution: na
Organization: The Portal System (TM)
Lines: 16

>Forgive me for what may be an ignorant question, but is there a version
>of the 386 that doesn't have problems with TLB misses while floating
>point stuff is going on?  We have ``double sigma'' parts, and they
>exhibit the problem.  For a while, I thought that the double sigmas
>fixed the bug; I guess I was wrong.

The double-sigma parts have a 32-bit multiply that works; they have
all 21 of the errata, however, including the paging/fpu problem.  The
"D-step" parts supposedly fix all known problems; they are marked
80386DX.  Curiously, the DX is what identifies the chip as a D-step part,
but the D is not the step number.  It is supposedly just a coincidence
that the DX nomenclature was added at the same time that they switched to
the D step.  SX suffix is for Single-wide (16-bit) data bus, DX is for
Double wide (32-bit) I'm told. Perhaps there will be a 486QX ?? (64-bit bus)

Michael Slater, Microprocessor Report     mslater@cup.portal.com