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From: valley@gsbsun.uchicago.edu (Doug Dougherty)
Newsgroups: comp.binaries.ibm.pc.d
Subject: Re: v11i233, v11i233: conex60, communications program
Message-ID: <1991Apr25.160845.9047@midway.uchicago.edu>
Date: 25 Apr 91 16:08:45 GMT
References: <1991Apr25.030426.11398@cbfsb.att.com>
Sender: news@midway.uchicago.edu (NewsMistress)
Organization: University of Chicago
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mbb@cbnewsb.cb.att.com (martin.brilliant) writes:

>I tried CONEX60 on my XTurbo10 because I liked the idea of having a
>graphics terminal emulator.  For various reasons I have a mouse on
>COM1 and a printer on COM2, so my 1200-baud modem is configured as
>COM4.  This works well with Boyan 4.0 as well as another terminal
>emulator used at Bell Labs.

I have this same sort of problem (too many serial devices).  Basically,
the problem is that by default COM3 shares its IRQ level with COM1 (As does COM4
with COM2), which means they share the same hardware interrupt (8 + IRQ level),
which means that you can't be running two interrupt handlers on both of
any pair of "joined" ports.  My guess is that the other comm pgms you
have used were either not as interrupt intensive (Omigosh!  Tell me they
don't use the BIOS serial routines!) *or* were better written than CONEX
(Is that CONEX [like conehead] or COMEX?) and were able to deal with it.

In any case, I have found that you cannot run an interrupt driven comm
pgm on the same IRQ level as the $25 network.  One or the other will
fail...

A solution, if you can do it, is to re-program your serial card so that
the extra COM ports use different IRQs (e.g., IRQ5)  Unfortunately, my
cheapie serial card can't do this.  The real question is, "Why did they
do this to us in the first place?"  (Anyone know?)
--

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