Article View: comp.os.msdos.programmer
Article #7369Re: How can a TSR detect if it has been installed?
From: X session
Date: Thu, 27 Jun 1991 04:11
Date: Thu, 27 Jun 1991 04:11
26 lines
1723 bytes
1723 bytes
Use int 2fh
quoting Ping-Shun Huang:
(1) Grab a completely unused interrupt/service and have your TSR return
identification codes when that interrupt/service is called: e.g.
Interrupt $21, AX=$FEED is probably unused, your TSR could grab it and
return non-trivial data in the registers, BX=$DEAF and CX=$BEAD and
DX=$FEED, the combination of which is unlikely to be accidentally
duplicated by another program. Your TSR's installation routine can then
check before continuing. Problem with this method: potential (although
darn unlikely) conflicts with other TSR's if by chance two programmer
decide on the same interrupt/service and ID codes.
But use AH=2fh (I hope I got it right) instead DOS uses this one
especially for this purpose (print graftabl append etc.)
I might be able to find which program use which code, if I find it I'll
post it.
I always use anything above 80h and it seems to work.
Hope this helps
grtnx Martijn
nykerk@mcrcim.mcgill.ca
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!uunet!bonnie.concordia.ca!thunder.mcrcim.mcgill.edu!McRCIM.McGill.EDU!xsession From: xsession@McRCIM.McGill.EDU (X session) Newsgroups: comp.os.msdos.programmer Subject: Re: How can a TSR detect if it has been installed? Message-ID: <1991Jun27.041153.17579@thunder.mcrcim.mcgill.edu> Date: 27 Jun 91 04:11:53 GMT References: <0094A83A.9AE8E1A0@MAPLE.CIRCA.UFL.EDU> <PSHUANG.91Jun23164405@beeblebrox.mit.edu> Sender: news@thunder.mcrcim.mcgill.edu Reply-To: xsession@McRCIM.McGill.EDU (X session) Organization: McRCIM, McGill University Lines: 27 Nntp-Posting-Host: picasso.mcrcim.mcgill.edu