Date: Wed, 22 Jan 1997 08:53:42 +0200 (IST)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
To: Gene Buckle <geneb AT web DOT wa DOT net>
cc: djgpp AT delorie DOT com
Subject: Re: Passing a parameter to interrupt handler.
In-Reply-To: <Pine.LNX.3.93.970121162026.5446D-100000@web.wa.net>
Message-ID: <Pine.SUN.3.91.970122085048.29370J-100000@is>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII


On Tue, 21 Jan 1997, Gene Buckle wrote:

> > Once upon a time (on 20 Jan 97 at 23:35) Gene Buckle said:
> > 
> > > Of all the great examples I've found for writing IRQ handlers, I've not seen
> > > one that documents how to pass a parameter (specifically a pointer to a
> > > structure) to the installed routine.
> > The only way I can see is through shared (and locked!) memory.
> 
> The whole program is locked in memory via the CRT0 flags.  My problem is
> that the program calling the interrupt (0xef in this case) won't be the
> same one that has the code for the actual ISR in it. ;)

Allocate some DOS memory and pass the data through that buffer.  You will 
have to devise a mechanism to publish the address of that buffer, so the 
program which allocated them could tell the address to the other programs.
One possibility to pass this address is an environment variable; another 
is a disk file.