Date: Mon, 9 Feb 1998 17:08:18 +0200 (IST)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
To: Yedema <yedema AT natlab DOT research DOT philips DOT com>
cc: djgpp AT delorie DOT com
Subject: Re: irq handling through signals
In-Reply-To: <uqvk9b53rcc.fsf@natlab.research.philips.com>
Message-ID: <Pine.SUN.3.91.980209170439.9861J-100000@is>
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On Mon, 9 Feb 1998, Yedema wrote:

> Can anyone tell me how I can trap interrupts in djgpp without using the dpmi 
> stuff?

You can't, in general.  You can only catch those interrupts which are 
converted to signals.  SIGINT, SIGALRM and SIGTRAP are the only ones 
which are.

> Info says that signals >255 are the interrupts (if I remember 
> correctly) .

Signals < 256 were *supposed* to be generated by interrupts, but it has 
never been implemented.

> I'd like to trap COM1, COM2 and the keyboard interrupt see. 

The only way is the one described in the FAQ and in several other 
DJGPP-oriented tutorials.  You have to use the DPMI functions.