Bell Technologies UNIX SVR3

[Chris Lewis]

In article <1209 at maccs.UUCP> nusip at maccs.UUCP (Mike Borza) writes:
|In article <2686 at ihuxv.ATT.COM> bareta at 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