From: "Charles Sandmann" <sandmann AT clio DOT rice DOT edu>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: InDOS Flag
Date: Mon, 21 Apr 1997 23:20:17
Organization: Aspen Technology, Inc.
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Message-ID: <335bf631.sandmann@clio.rice.edu>
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Reply-To: sandmann AT clio DOT rice DOT edu
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To: djgpp AT delorie DOT com
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> the Idle interrupt, Int 28h.  A TSR should hook that interrupt if it
> needs to be able to pop up during this time.  Note that for DJGPP
> programs, the complication here is that Int 28h is a *software* interrupt 
> and therefore is not reflected to protected mode by the DPMI host.  

In this case you allocate a RMCB (real mode callback) and replace int 28h
with this value.  This will cause a call to your PM code whenever int 28h
was called.  You could also use RMCBs to install a RM entry to your PM
code - so you can essentially do everything in a PM TSR as you could in
a RM one (theoretically).