Path: utzoo!dciem!nrcaer!sce!cognos!craigs
From: craigs@cognos.UUCP (Craig Statchuk)
Newsgroups: comp.sys.ibm.pc
Subject: Re: COM port chip info needed
Message-ID: <8112@cognos.UUCP>
Date: 20 Mar 90 20:38:13 GMT
References: <22946@pasteur.Berkeley.EDU>
Reply-To: craigs@cognos.UUCP (Craig Statchuk)
Organization: Cognos Inc., Ottawa, Canada
Lines: 26

In article <22946@pasteur.Berkeley.EDU> wooters@icsi.berkeley.edu (Chuck Wooters) writes:
>I discovered that the card was missing a chip in the
>socket marked COM2 :-(.

Most of the cards I have run into use the Intel 8250 (or equivalent) although
Motorola chips show up occasionally -- how to tell?  Get the data sheets
and the data / ground connections -- the chip required should be obvious.

You should also look for spare 14 pin DIP sockets "near" the missing COM2
socket.  These sockets are typically used for the RS232 line drivers 
(MC1488 and MC1489).  Many manufacturers seem to leave these chips out
when providing "optional" COM ports.  All of these chips are very common
and very inexpensive (about four dollars in total from any good discount part
distributor) -- Avoid your friendly computer dealer -- I have seem these
upgrade packages advertised for as much as $20.






-- 
Craig Statchuk           P.O. Box 9707        uunet!mitel!sce!cognos!craigs
Cognos Incorporated      3755 Riverside Dr.
HUMAN: (613) 738-1440    Ottawa, Ontario
FAX:   (613) 738-0002    CANADA  K1G 3Z4