From: "Tonu Aas" <tonu AT ids DOT ee>
Newsgroups: comp.os.msdos.djgpp
References: <b1qcar$16070j$1 AT ID-83062 DOT news DOT dfncis DOT de> <03a701c2ccf6$5ccd6160$0600000a AT broadpark DOT no>
Subject: Re: Determining interrupt vector for serial port
Date: Wed, 5 Feb 2003 11:49:17 +0200
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To: djgpp AT delorie DOT com
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> > But I've been unable to discover how to "read" the associated IRQ
> > value for each port.  So far I've found them hardcoded as 4, 3,

> 1. mask off all interrupts in the PIC (to prevent false positives)
> 2. clear the in-service bits
> 3. issue an UART command that raises it's IRQ line (e.g. an internal
>   loopback test)
> 4. poll all in-service bits in the PIC
> 5. and finally restore the PIC mask.

Does this work in Windows DOS session also ?
Maybe its not - PIC and UARTS are virtual.

I think that only working and most portable way is to use
some configuration in whatever form.

Tõnu.