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Path: utzoo!watmath!clyde!cbosgd!ihnp4!zehntel!dual!qantel!intelca!hplabs!hao!seismo!rlgvax!guy
From: guy@rlgvax.UUCP (Guy Harris)
Newsgroups: net.unix-wizards
Subject: Re: Autobaud Modems
Message-ID: <294@rlgvax.UUCP>
Date: Tue, 11-Dec-84 18:17:11 EST
Article-I.D.: rlgvax.294
Posted: Tue Dec 11 18:17:11 1984
Date-Received: Sat, 15-Dec-84 00:12:26 EST
References: <32300009@smu.UUCP>
Organization: CCI Office Systems Group, Reston, VA
Lines: 18

> Some time ago there was a lot of debate about auto-baud modems
> and different ways to do them.  The solutions were all done totally
> in software.  This solution uses hardware to aid the software and
> the only problems with it is that it can only be used at two
> speeds.  Typically the speeds are 1200 and 300.
> 
> The concept is quite simple.  The ring detect line is not used for
> anything usefull (at least in the DH driver on a 4.2 system).  Most
> autobaud modems have a speed line availiable on the RS-232 connector.
> So it is simply a matter of connecting the speed line of the modem
> to the ring detect line of the DH.

If I remember correctly, there was stuff in V7 to do exactly that on
a DH (there was also stuff in V7 to adaptively set the silo alarm level
on DHes, and that wasn't in 4.xBSD either).

	Guy Harris
	{seismo,ihnp4,allegra}!rlgvax!guy