Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!usc!cs.utexas.edu!rice!uw-beaver!zephyr.ens.tek.com!tekfdi!videovax!dougs
From: dougs@videovax.tv.tek.com (Doug Stevens)
Newsgroups: comp.sys.ibm.pc.programmer
Subject: Re: How do get COMx to do 19,200 baud
Summary: Baud rates to 115,200.
Message-ID: <5745@videovax.tv.tek.com>
Date: 5 Mar 90 17:29:42 GMT
References: <32894@prls.UUCP> <2956@jato.Jpl.Nasa.Gov> <8422@chaph.usc.edu>
Distribution: usa
Organization: Tektronix TV Measurement Systems, Beaverton OR
Lines: 11

In article <8422@chaph.usc.edu>, wilber@nunki.usc.edu (John Wilber) writes:
> ... you can get some VERY HIGH baud
> rates from a serial port, as high as 100+ kbaud ...

Specifically, you can get up to 115,200 baud by writing directly to the
8250. You do need to be careful -- not all 8250's are guaranteed to
run with a divide-by-one in the oscillator control register with those
crystal frequencies (Western Digital, if I remember, is one of these).

You also need to play some software tricks to ensure that the transmitting end
does not over-run the receiving end with these baud rates.