Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!utgpu!water!watnot!watmath!clyde!rutgers!seismo!mimsy!chris
From: chris@mimsy.UUCP
Newsgroups: comp.unix.wizards
Subject: Re: String Handling and run-time libraries
Message-ID: <6111@mimsy.UUCP>
Date: Fri, 3-Apr-87 10:51:19 EST
Article-I.D.: mimsy.6111
Posted: Fri Apr  3 10:51:19 1987
Date-Received: Sun, 5-Apr-87 08:12:01 EST
References: <15292@amdcad.UUCP> <978@ames.UUCP> <15694@sun.uucp> <6042@mimsy.UUCP> <724@killer.UUCP>
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 28

In article <724@killer.UUCP> jfh@killer.UUCP (John Haugh) writes:
>I seem to remember for freshman days that there are registers (other than
>R0 -> R15 that contain the information about your CPU type.

Yep.

>Maybe some of them can be accessed in USER mode...

Nope.

The register in question is the `SID', System IDentification,
register.  It is read with an `mfpr', Move From Processor Register,
instruction, which is privileged.

Incidentally, a `get me the SID' call is probably a bad idea.
There is a story behind this:  The format of this register varies
with each Vax line.  In 780s, it contains what looks like a serial
number (but in fact is a plant and manufacturing number, which is
not the same).  This has led a number of software vendors (VMS
types, fortunately) to attempt to enforce licenses by using the
VMS `get me the SID' system call.  These vendors were just a bit
too clever, for now, when one's 8600 is upgraded, such software no
longer works, as the SID changes to reflect the upgrade.  On the
8600, you see, the SID contains not a manufacturing number, but
instead, several version numbers.
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7690)
UUCP:	seismo!mimsy!chris	ARPA/CSNet:	chris@mimsy.umd.edu