Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!ucbvax!pasteur!dorothy.Berkeley.EDU!cs9a-ax
From: cs9a-ax@dorothy.Berkeley.EDU (Mike Morrison)
Newsgroups: comp.binaries.ibm.pc.d
Subject: Re: Sys Req - key.
Keywords: SysReq
Message-ID: <20358@pasteur.Berkeley.EDU>
Date: 6 Dec 89 04:07:01 GMT
References: <187@nmtvax.nmt.edu> <1989Dec5.190738.17084@ux1.cso.uiuc.edu>
Sender: news@pasteur.Berkeley.EDU
Reply-To: cs9a-ax@dorothy.Berkeley.EDU.UUCP (Mike Morrison)
Organization: University of California, Berkeley
Lines: 24

In article <1989Dec5.190738.17084@ux1.cso.uiuc.edu> wang@cs.uiuc.edu (Eric Wang) writes:
-In article <187@nmtvax.nmt.edu> jeff@nmtvax.nmt.edu (- Jeff -) writes:
--This is probably a useless question, but there is a mysterious key on my 
--XT-keyboard called the 'Sys Req' key. I've seen this key on many other 
--IBM and compatible keyboards and I am just curious if anyone knows what it 
--is for and how to access it? I can't seem to find anything in my DOS 3.3 
--manual about it. Anyone know what this key is for? Just curious...
-
-This is only what little I know of SysReq.  It does not claim to be a
-comprehensive, technical treatise.
-
-The SysReq key is indeed a special key.  Of all keys on the keyboard, it is
-the only one which is NOT processed through the INT 09 Keyboard interrupt.
-Instead, it has a special interrupt all to itself (INT 15, I believe).  It

This is at least partially false.  On my machine, an XT clone, the sys-req
key DOES use int 09.  (int 15h is for cassette io).  It generates ascii 00, 
scan code 37h.  When num-lock is on it generates ascii 77h, scan code 54h.
The rest of the posting sounds ok to me, though -- I don't have any idea what
the key is supposed to be used for.

Mike Morrison
cs9a-ax@dorothy.berkeley.edu
morrison@ocf.berkeley.edu