Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!ucsd!pacbell.com!pacbell!att!mcdchg!laidbak!obdient!vpnet!cgordon
From: cgordon@vpnet.chi.il.us (Gordon Hlavenka)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: Baud vs. bps.
Keywords: 386 vs. 486, Unix, EISA
Message-ID: <26d955ed-16c.4comp.sys.ibm.pc.hardware-1@vpnet.chi.il.us>
Date: 27 Aug 90 17:55:05 GMT
References: <849@idcapd.idca.tds.philips.nl> <4188@trantor.harris-atd.com>
Lines: 20

>THE LIGHTS DIM AS THE LEGEND BEGINS...
   (... a good explanation deleted here, go back and read it)

One that you probably use every day, with four bits per symbol:  Touch tones!
Each key on the keypad generates a pair of tones:  One is determined by the
ROW, and one by the COLUMN.  There is a "hidden" column (its tone is 1633
Hz) which is not present on a standard telephone keypad.

So, with 4 rows and 4 columns, there are 16 possible tone combinations. 
This allows the encoding of 4 bits (called a "nibble" for you budding
lexicologists) per symbol.

The typical minimum usable burst length is 50 milliseconds, with a 50
millisecond pause between bursts.  So this gives a baud rate of ten, and a
BPS rate of 40.  (The math is left as an exercise etc.)

-----------------------------------------------------
Gordon S. Hlavenka            cgordon@vpnet.chi.il.us
Disclaimer: I've fallen!  And I can't get up!
            So how could I have expressed an opinion?