Date: Sun, 9 Aug 1998 19:19:30 +0300 (IDT)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
To: Nate Eldredge <nate AT cartsys DOT com>
cc: Endlisnis <s257m AT unb DOT ca>, Rylan <rylan AT inbtekom DOT co DOT za>, djgpp AT delorie DOT com
Subject: Re: How to generate an interrupt in AT&T asm
In-Reply-To: <35CDB258.6CF827BA@cartsys.com>
Message-ID: <Pine.SUN.3.91.980809191747.29878B-100000@is>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Precedence: bulk


On Sun, 9 Aug 1998, Nate Eldredge wrote:

> >     This program compiled and ran as I expected, changing the display into
> > VGA
> > mode.  I thought you had to switch to real-mode to execute an interrupt, or
> > is
> > that done in this case by the DPMI server?? 
> 
> I believe that an interrupt is issued in real mode if there is no
> protected mode handler for it.  I'm not sure of this, however.  The DPMI
> spec might discuss it.

AFAIK, the DPMI spec *requires* that.  Even if not, that is how things 
work in practice.

But issuing the interrupt via __dpmi_int is safer in some borderline 
cases such as INT 2Fh under Windows etc.