From: Vinzent Hoefler <JeLlyFish DOT software AT gmx DOT net>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Libnet serial port problem
Date: Wed, 15 Jan 2003 10:07:01 -0500
Organization: JeLlyFish software
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Reply-To: djgpp AT delorie DOT com

Ismo Salonen wrote:

> Actually the problem is hardware related. On older computers the IRQ
> line is
> high level active. Each uart drives the irq line it is connected to
> via tristate buffer. The buffer is enabled with a bit in the uart. If
> two uarts drive the same line then results are unpredictable.

So this is bad hardware design. As always.

But anyway, the OP talked of COM1/2. Those ports usually do not share 
the same IRQ.


Vinzent.

-- 
Ten years of rejection slips is nature's way of telling you to stop
writing.
                -- R. Geis