Path: utzoo!utgpu!jarvis.csri.toronto.edu!helios.physics.utoronto.ca!ists!yunexus!maccs!cs4g6ag
From: cs4g6ag@maccs.dcss.mcmaster.ca (Stephen M. Dunn)
Newsgroups: comp.sys.ibm.pc
Subject: Re: COM port chip info needed
Message-ID: <25FC2B2D.27454@maccs.dcss.mcmaster.ca>
Date: 12 Mar 90 23:05:17 GMT
References: <22946@pasteur.Berkeley.EDU>
Reply-To: cs4g6ag@maccs.dcss.mcmaster.ca (Stephen M. Dunn)
Organization: McMaster University, Hamilton, Ontario
Lines: 20

In article <22946@pasteur.Berkeley.EDU> wooters@icsi.berkeley.edu (Chuck Wooters) writes:
$I have a generic (made in Taiwan) multi I/O card.  It
$has a printer port/clock calend/game/ and (I thought)
$two serial ports.  I bought the card a couple of years
$ago, and until recently had no need for the second 
$serial port.  When I tried to hook my mouse to COM2,
$I discovered that the card was missing a chip in the
$socket marked COM2 :-(.

   All of the I/O cards I've seen (granted, not many) require three
chips to upgrade to a second serial port.  For my board, these are
a 16450 (UART), MC1488P or SN75188 (converts TTL levels to RS-232),
and MC1489P or SN75189 (converts RS-232 levels to TTL).  All three
chips should be available at any half-decent electronics retailer
(for that matter, even Radio Shack used to sell the latter two).
-- 
Stephen M. Dunn                               cs4g6ag@maccs.dcss.mcmaster.ca
          <std_disclaimer.h> = "\nI'm only an undergraduate!!!\n";
****************************************************************************
    "So sorry, I never meant to break your heart ... but you broke mine."