Date: Tue, 9 Jun 1998 18:08:41 +0300 (IDT)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
To: Steve Isaacs <ToolsSmith AT usa DOT net>
cc: djgpp AT delorie DOT com
Subject: Re: Newbie application question.
In-Reply-To: <3578ACFB.5C91A807@usa.net>
Message-ID: <Pine.SUN.3.91.980609180714.16324H-100000@is>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
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On Fri, 5 Jun 1998, Steve Isaacs wrote:

> > >  - What would be needed to install multiple handers?
> > 
> > I don't understand this.  Do you mean to have them on some chain,
> > whereby each handler calls the previous one?
> 
> No and yes.
> 
> No, more like shared libraries or DLLs each loaded separately and
> callable from real-mode as well as from each other via software
> interrupts (unlike shared libraries -- no late binding).
> 
> And, to a certain degree, yes. We likely will have some instances where
> interrupt chaining will be required. For example, a network redirector
> that uses the INT 2F multiplex protocol. Or another example would be an
> INT 15 4F based keyboard mapper.

AFAIK, the only way to achieve this is to arrange for every new DLL that 
hooks an interrupt to chain to the previous handler when it's done, and 
restore the interrupt table when it unloads.