Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!cs.utexas.edu!uunet!jwt!john
From: john@jwt.UUCP (John Temples)
Newsgroups: comp.sys.ibm.pc.misc
Subject: Re: Replacing an 8250 with a 16550a chip
Keywords: RS-232 Breakfast Cereal Communications
Message-ID: <1991Apr21.165907.1979@jwt.UUCP>
Date: 21 Apr 91 16:59:07 GMT
References: <1991Apr20.103614.1295@agora.rain.com>
Distribution: na
Organization: Private System -- Orlando, FL
Lines: 23

In article <1991Apr20.103614.1295@agora.rain.com> tedm@agora.rain.com (Ted Mittelstaedt) writes:
>  Does anyone know if the pin-out on this chip is the same as the pinout of
>  the older 8250 chip?

Technically, no, it's not.  From TFM:

"Pin for pin compatible with the existing 16450 except for CSOUT (24)
and NC (29)."

"Most serial cards that currently use the NS16450 don't use these pins,
so in those situations the NS16550A could be used as a plug-in upgrade."

Since the 16450 is functionally equivalent to the 8250, you shouldn't have
any problems.  I've plugged 16550s into 8250 cards, and they worked fine.

>I have a serial card that uses an 8250 and I would like to use the 16550a 
>so when I run DeskView the serial chip isin't chewing up all the processor
>time.

Keep in mind that your communications software must be 16550-aware in order
for you to see any real benefit in the upgrade.
-- 
John W. Temples -- john@jwt.UUCP (uunet!jwt!john)