Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!pt.cs.cmu.edu!b.gp.cs.cmu.edu!Ralf.Brown@B.GP.CS.CMU.EDU
From: Ralf.Brown@B.GP.CS.CMU.EDU
Newsgroups: comp.sys.ibm.pc
Subject: Re: 'Sys Req' - key.
Message-ID: <257d155f@ralf>
Date: 6 Dec 89 12:34:23 GMT
Sender: ralf@b.gp.cs.cmu.edu
Organization: Carnegie Mellon University School of Computer Science
Lines: 28
In-Reply-To: <1989Dec5.181045.10621@ux1.cso.uiuc.edu>

In article <1989Dec5.181045.10621@ux1.cso.uiuc.edu>, kds10773@uxa.cso.uiuc.edu (Ken S.) wrote:
 >The SysReq key can be polled using entry point 0x85 of int 0x15 (system
 >services), however I believe that's only implemented on AT's, so on your
 >XT keyboard, it's most likely useless.  I'm afraid I also don't know
 >of any less technical ways to access it.

You can't poll SysRq that way, since the BIOS *calls* INT 15/AH=85h whenever
the SysRq key is pressed or released.  If you want to get SysRq, you have to
hook INT 15 and check for AH=85h.


INT 15 - OS HOOK - SYSTEM REQUEST KEY PRESSED (AT,XT2,XT286,CONV,PS)
	AH = 85h
	AL = 00h press
	   = 01h release
Return: CF set on error
	AH = status
Note:	called by keyboard decode routine
SeeAlso: INT 09

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