Path: utzoo!attcan!uunet!lll-winken!lll-lcc!ames!husc6!ogccse!blake!djo7613
From: djo7613@blake.acs.washington.edu (Dick O'Connor)
Newsgroups: comp.sys.ibm.pc
Subject: Re: PC's Limited AT Serial Port Problem
Message-ID: <489@blake.acs.washington.edu>
Date: 4 Jan 89 23:38:00 GMT
References: <464@blake.acs.washington.edu> <19500022@uxh.cso.uiuc.edu>
Reply-To: djo7613@blake.acs.washington.edu (Dick O'Connor)
Organization: University of Washington, Seattle
Lines: 30

I'm amazed at the number of responses I received concerning the problem I
was having with a PC's Limited AT and a serial port that wouldn't respond
correctly to a working external 1200 baud modem.  Thanks Pete, Leonard,
Mike, Cris, Rich, Thomas, Jim, John, Bill, and Tom; some of you hit it
right on the nose, others were awfully close.  A couple of you were
interested in the final result, so I'm posting the solution we arrived at
after intense absorption of the DIO-200 I/O Card manual.

The user was trying to use the primary serial port (serial port #1) as COM2
because he had a laser printer assigned to COM1.  This is OK as long as you
change the default switch and jumper settings on the I/O card to reflect
this.  To get the serial port to respond as COM2, the interrupt jumper must
be set for IRQ3 (not IRQ4, the default), and the switch settings change
from the default ON ON to ON OFF.  One of these things wasn't set
correctly, and when he set the both in synch, everything was beautiful.

Moral:  Yes, yes, ReadTheFriendlyManual; however, I still think I/O card
documentation could improve a *lot* with the addition of a few "scenario"
style examples.  "Chip has a laser printer assigned to COM1 and wants to
add a modem to COM2.  In this case, he simply..."

Thanks again, netfolk, for your swift and helpful responses!!!

-Dick O'Connor
 Washington Department of Fisheries
 Disclaimer: Well,...they approve of this posting, I'm sure!

P.S. Apologies to Bill Maine, Tom Thackeray, and John P. Nelson; tried
to mail my thanks to you, but I must have copied your addresses incorrectly
and our local mailer balked.