Xref: utzoo comp.unix.xenix:2358 comp.unix.microport:748
Path: utzoo!lsuc!spectrix!clewis
From: clewis@spectrix.UUCP (Chris Lewis)
Newsgroups: comp.unix.xenix,comp.unix.microport
Subject: Re: Bell Technologies UNIX SVR3
Message-ID: <638@spectrix.UUCP>
Date: 31 May 88 21:17:48 GMT
References: <2686@ihuxv.ATT.COM> <1209@maccs.UUCP>
Reply-To: clewis@spectrix.UUCP (Chris Lewis)
Organization: Spectrix Microsystems Inc., Toronto, Ontario, Canada
Lines: 22

In article <1209@maccs.UUCP> nusip@maccs.UUCP (Mike Borza) writes:
|In article <2686@ihuxv.ATT.COM> bareta@ihuxv.ATT.COM (Benyukhis) writes:
|>Can anyone familiar with Bell Technologies UNIX SVR3 provide me with
|>some information on the product i.e. 
|>...
|>I am running on PC's Limited 286 machine.
|
|Unless things have changed very recently, BT's SVR3 only runs on 386
|machines, so you're stuck with either SVR2 (uPort's SV/AT) or Xenix
|286.  I could be wrong about this (probably!), but I doubt you'll see
|a SVR3 port to 286 machines.  The overhead to support demand paging
|on 286's would destroy performance.

From what I've heard, full SVR3 compliance more or less requires that
the CPU supports atomic 32 bit operations.  Eg: you can update a long
without having interrupts kill you in the middle.  Eg: resource locking
inside the kernel.  Since a 286 can't (without protecting EVERYTHING
with disabled interrupts), you'll never see SVR3 on a 286.
-- 
Chris Lewis, Spectrix Microsystems Inc,
UUCP: {uunet!mnetor, utcsri!utzoo, lsuc, yunexus}!spectrix!clewis
Phone: (416)-474-1955