Path: utzoo!attcan!telly!nebulus!druid!darcy
From: darcy@druid.uucp (D'Arcy J.M. Cain)
Newsgroups: comp.sys.ibm.pc
Subject: Re: 'Sys Req' - key.
Keywords: What is it for?
Message-ID: <1989Dec8.121106.3841@druid.uucp>
Date: 8 Dec 89 12:11:06 GMT
References: <189@nmtvax.nmt.edu>
Reply-To: darcy@druid.UUCP (D'Arcy J.M. Cain)
Organization: D'Arcy Cain Consulting, West Hill, Ontario
Lines: 24

In article <189@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...
>
> 				- Jeff -
>				jeff@nmtvax.nmt.edu

This key can not be read by normal keyboard reads.  To use this key you
must intercept int 15h and test for ah=85h.  If not pass through to the
old int 15h.  If so the look at al.  If it is 0 then the SysReq key has
just been pressed.  If 1 the it has just been released.  I used this one
to turn a Hercules graphics screen into a negative of itself.  There aren't
many programs that make use of this key.  I suspect that that is because
it is only available on AT's.


-- 
D'Arcy J.M. Cain (darcy@druid)     |   "You mean druid wasn't taken yet???"
D'Arcy Cain Consulting             |                    - Everybody -
West Hill, Ontario, Canada         |
No disclaimers.  I agree with me   |