Xref: utzoo comp.dcom.modems:2631 comp.mail.uucp:2118
Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!wasatch!utah-gr!uplherc!sp7040!obie!wes
From: wes@obie.UUCP (Barnacle Wes)
Newsgroups: comp.dcom.modems,comp.mail.uucp
Subject: Re: UUCP g stats / baud isnt bps
Summary: Nope, you missed!
Message-ID: <210@obie.UUCP>
Date: 7 Oct 88 04:04:45 GMT
References: <183@arnold.UUCP> <1988Sep20.184054.2403@utzoo.uucp> <184@arnold.UUCP> <13842@mimsy.UUCP>
Organization: the Well of Souls
Lines: 34

In article <1464@netmbx.UUCP> blume@netmbx.UUCP (Heiko Blume) writes:
> as far as i remember the baud rate tells you how many changes of the
> discrete signal levels are possible.

In article <13842@mimsy.UUCP>, chris@mimsy.UUCP (Chris Torek) writes:
> Not exactly.  `Baud rate' means `number of channel symbols per unit
> time'; multiplying this by `number of bits per channel system' gives
> the more familiar bits per unit time, typically bits per second.

Nope, Heiko was right.  Baud refers to the number of state changes the
carrier makes per unit time.  How this relates to the bit rate depends
on the modulation scheme you are using (NRZ, NRZ1, diphase, etc.).

> It may be best to stick with `bps'.  After all, I use a Telebit TB+
> modem at 19200 *baud* ... between the serial port on the TB+ and that
> on the Vax!  That part of the link runs at 19200 channel symbols per
> second, with each channel symbol conveying one bit.  The modem-to-
> modem link uses something else entirely, but I never said which link
> was `19200 baud'.

Actually, it is highly likely that you are using the TB+ at *19200 bps*
since that is probably what your computer is sending out.  With the way
RS232 signals are encoded, the actual baud rate is somewhat slower than
the bit rate, since adjacent bits of the same type do not cause a state
change.  In other words, if you send out an ASCII NUL character, you
will only get two state changes in the entire byte - one for the start
bit, and one for the stop bit.  If you are transmitting at 19,200 bps,
this give you an effective baud rate of 3840!

-- 
                     {hpda, uwmcsd1}!sp7040!obie!wes

         "How do you make the boat go when there's no wind?"
                                 -- Me --