Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!cbmvax!grr
From: grr@cbmvax.UUCP (George Robbins)
Newsgroups: comp.unix.ultrix
Subject: Re: How do you identify VAX/PMAX cpu's from software?
Keywords: CPU identification
Message-ID: <7015@cbmvax.UUCP>
Date: 30 May 89 20:14:48 GMT
References: <40619@bbn.COM> <105@asihub.UUCP> <7005@cbmvax.UUCP> <1242@riscy.dec.com>
Reply-To: grr@cbmvax.UUCP (George Robbins)
Distribution: na
Organization: Commodore Technology, West Chester, PA
Lines: 30

In article <1242@riscy.dec.com> frank@croton.DEC.COM (Frank Wortner) writes:
> In article <40619@bbn.COM>, fkittred@bbn.com (Fletcher Kittredge) writes:
> > In article <105@asihub.UUCP> dan@asihub.UUCP (Dan O'Neill) writes:
> > > Is there a way to determine the class of a VAX or PMAX cpu under
> > > Ultrix?...
> > 
> > Well, I don't have access to all of these systems, so this is a guess.  Try
> > the uname() system call and check the resulting structure...
> 
> Fletcher, you are right.  Ultrix uname does exactly the minimum you describe.
> Unfortunately, it does not descriminate amoung the various CPU implementations
> That is, uname will say that the machine is a VAX, but nothing more.  It could
> be a 780, 3600, or whatever.  I'm afraid that bit-twiddling of magic words
> obtained from the kernel is needed to get more information.

Not too mysterious, the kernel variables _cpu, _cpu_subtype and mayhaps
_cpu_sub_subtype seem to be the basic story.  Values for cpu and subtype
show up in /sys/vax/cpu.h.  Of course there's no promise that the values
in a putative /sys/pmax/cpu.h don't overlap.

To emphasize an earlier point, this is not the kind of stuff that an
application should be looking at.  Unless there's some really good reason
for peeking under the skirts, the application should be insensitive to
cpu type or should a least view the matter as on of attributes rather
than instances.

-- 
George Robbins - now working for,	uucp: {uunet|pyramid|rutgers}!cbmvax!grr
but no way officially representing	arpa: cbmvax!grr@uunet.uu.net
Commodore, Engineering Department	fone: 215-431-9255 (only by moonlite)