Newsgroups: comp.os.msdos.programmer
Path: utzoo!censor!meadow!py
From: py@meadow.uucp (Peter Yeung)
Subject: Re: problems with com3 & com4
Message-ID: <1991Jan27.034726.15865@meadow.uucp>
Keywords: com3 com4
Reply-To: py@meadow.UUCP (Peter Yeung)
Organization: Amdahl Canada Ltd., Software Development Center
References: <1991Jan25.054228.157@frey.newcsatle.edu.au>
Distribution: comp
Date: Sun, 27 Jan 91 03:47:26 GMT

In article <1991Jan25.054228.157@frey.newcsatle.edu.au> kaos@frey.newcsatle.edu.au (Iain `Kaos' Holmes) writes:
>
>	cause i can write to the ports and they react but i think the interupts
>
>	are screwy...
>

Which interrupt are you using? Since the original PC does not have provision
for com3/4, the interrupt to be used is implementation dependent.
Most implementations chose to share the interrupts with those being used
by com1/2. Also, typically, those async cards supporting com3/4 also allow
the user to choose the interrupt/port address etc. So, make sure you are
catching the interrupt same as the one setup on the card!

>-- 
>    Iain "Kaos" Holmes.            +---------+ 
> ACSnet :kaos@frey.nucastle.edu.au |   ~ ~   | Remember, Always keep your feet
>                                   |  (o o)  | on the ground, your eye on the 
> Phone : (049) 26-2926 home        |   (_)   | clock, your finger on the pulse


-- 
Peter Yeung     Amdahl Canada Ltd., Software Development Center
                2000 Argentia Road, Plaza 2, Suite 300
                Mississauga, Ont.   L5N 1V8
                Phone: (416) 542-6300    Fax: (416) 858-2233