Path: utzoo!utgpu!watmath!att!ucbvax!tut.cis.ohio-state.edu!cs.utexas.edu!ut-emx!allred
From: allred@ut-emx.UUCP (Kevin L. Allred)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Mylex Motherboards - Why not?
Summary: SCO says their UNIX works on 386sx
Message-ID: <17241@ut-emx.UUCP>
Date: 17 Aug 89 17:17:15 GMT
References: <4843@bgsuvax.UUCP> <17144@ut-emx.UUCP> <1711@crdgw1.crd.ge.com>
Organization: UT-Austin, Dept. of Chem. Engr
Lines: 30

In article <1711@crdgw1.crd.ge.com>, davidsen@sungod.crd.ge.com (ody) writes:
> In article <17144@ut-emx.UUCP> allred@ut-emx.UUCP (Kevin L. Allred) writes:
> | UNIX prices to drop.  I do know that Intel says their UNIX won't run
> | on a 386sx ( you figure the company that makes the processor would
> | know what to change :-).  I don't know about the other UNIX vendors.
>   Has anyone else verified this? Several 386SX vendors have sworn to me
> that their systems would run Xenix and UNIX. Is this something
> particular to Intel? I assume that you can tell if the system is an SX
> or not, but why do it?

Since my earlier posting, I talked to a sales rep. for SCO and he said
that their 386 products would run on a 386sx no problem, but remember
you can believe everything a sales rep tells you ;-).  He did ask if I
had an AT bus, and it was after I said yes, that he said no problem.
Maybe there is problem in microchannel based 386sx systems.  Intel
wasn't very clear as to why their current unix product wouldn't run on
a 386sx.  It had something to do with not being able to do full 32 bit
memory accesses in the first megabyte of memory (huh?).  I have know
idea why this would be a problem, as it should just take longer to do
32 bit accesses.  As to being able to tell the difference between a
386 and 386sx, all of the 386 specific software I have tried so far
has identified the processor as a 386 and run as advertised.  To tell
the difference, I think software would have to count the nember of
clock cycles to do 32 bit memory accesses.  I guess the time would be
around twice as long for the sx.
-- 

	Kevin Allred
	allred@emx.cc.utexas.edu
	allred@ut-emx.UUCP