Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!uxc!uxc.cso.uiuc.edu!ux1.cso.uiuc.edu!uxe.cso.uiuc.edu!mcdonald
From: mcdonald@uxe.cso.uiuc.edu
Newsgroups: comp.sys.ibm.pc
Subject: Re: 80386 DX step
Message-ID: <45900230@uxe.cso.uiuc.edu>
Date: 4 May 89 14:31:00 GMT
References: <535@cbnewsl.ATT.COM>
Lines: 18
Nf-ID: #R:cbnewsl.ATT.COM:535:uxe.cso.uiuc.edu:45900230:000:573
Nf-From: uxe.cso.uiuc.edu!mcdonald    May  4 09:31:00 1989


>Does anyone know *exactly* what the differences are
>between the 80386 DX step and the B1 step ?

Yes, Intel does. IBM PROBABLY does, though you never know with them.
Certainly, most certainly, God knows.

Other than that, the DX step is supposed to fix a problem with the
machine (mostly Model 80's) locking up if ALL of the following
happen:
    Running in native 386 or virtual 86 mode
    Paging is enabled
    certain sequences of 80387 and 80386 instructions are used

My Model 80 had the problem until a new motherboard with a DX
chip was installed.

Doug McDonald