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Posting-Version: version B 2.10.1 6/24/83; site mgweed.UUCP
Path: utzoo!watmath!clyde!cbosgd!ihnp4!mgnetp!mgweed!rjk
From: rjk@mgweed.UUCP (Randy King)
Newsgroups: net.unix
Subject: Framing errors and autobaud @ 2400
Message-ID: <15994@mgweed.UUCP>
Date: Fri, 22-Mar-85 13:09:37 EST
Article-I.D.: mgweed.15994
Posted: Fri Mar 22 13:09:37 1985
Date-Received: Sat, 23-Mar-85 02:18:27 EST
Distribution: net
Organization: AT&T Consumer Products - Montgomery Illinois
Lines: 25

<><><>

It seems that autobauding from 1200 down to 300 by means of a framing
error is quite reliable when the 300-baud user types almost any character.
Hence for years uucp info has contained strings like:   login:--login:
where the "--" implied "send CR".

The reverse did not work, so the 1200-baud user would send a BREAK to
upshift the remote to 1200; hence  login:-BREAK-login:  for the uucp info.

Now I am finding that downshifting from 2400 baud to 1200 baud more closely
resembles the 300->1200 upshift in that sending a BREAK is the more reliable
way.  It is not always the case, however.  There are times when just a CR
from my 1200 baud modem calling a tri-speed modem at 2400 baud will cause
the port to fallback to 1200.  Many times, however, a BREAK is required to
cause the downshift.

If you have had experience with 2400 baud autobauding, including upshifts and
downshifts among the speeds from 110->2400, I'd like to hear about your
findings.  This would be important information for future releases of UUCP
information from sites with >1200 baud modems.

						Randy King
						AT&T-CP@MG
						ihnp4!mogul!rjk