Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!husc6!rutgers!ames!ptsfa!hoptoad!dasys1!eravin
From: eravin@dasys1.UUCP (Ed Ravin)
Newsgroups: comp.sys.att,comp.unix.questions
Subject: Re: UUCP dialout, uugetty fighting...
Message-ID: <1252@dasys1.UUCP>
Date: Thu, 10-Sep-87 18:36:56 EDT
Article-I.D.: dasys1.1252
Posted: Thu Sep 10 18:36:56 1987
Date-Received: Sat, 12-Sep-87 16:49:16 EDT
References: <2896@psuvax1.psu.edu> <1463@chinet.UUCP> <18171@amdcad.AMD.COM> <1187@dasys1.UUCP> <1485@chinet.UUCP>
Reply-To: eravin@dasys1.UUCP (Ed Ravin)
Organization: Ministry of Information Retrieval, DZ-103
Lines: 27
Summary: Yes, DCD can be confusing
Xref: mnetor comp.sys.att:1206 comp.unix.questions:4004

In article <1485@chinet.UUCP> randy@chinet.UUCP (Randy Suess) writes:

(parts of my message about DCD sensing on modems is quoted)
>
>	I seem to be missing something with all this discussion of 
>	bi-directional modem use on 3b's.  As the above states, you have
>	to leave CD tied hi at all times for dial-out.  What happens on
>	dial-in when the carrier is inadvertently dropped?
( can someone else log into the session, will the system sense the hangup,
etc)

Oops.  Come to think of it, I once wondered about that, but never had the
problem.  Lord knows I've seemingly had every other possible problem with
modems and uugetty.  By the way, this was all on a 3b5 using uugetty and
BNU (HDB) UUCP.

The reason I didn't discuss that problem is that I didn't have it: and the
reason I don't think that problem occured to me is that the modems used here
toggle DCD low whenever someone hangs up.  I know that when I dial out and
the other side dumps me, "cu" reports "Disconnected" and exits on its own.
It must be sensing DCD, what else?  And it never would have been able to dial
out without DCD present.  So if your modem is smart enough to toggle DCD
low whenever the other side hangs up (loses carrier), the system will always
be able to sense a hangup and act appropriate CoOrganit