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From: dave@westmark.UUCP (Dave Levenson)
Newsgroups: comp.sys.att,comp.unix.questions
Subject: Re: UUCP dialout, uugetty fighting...
Message-ID: <152@westmark.UUCP>
Date: Sat, 5-Sep-87 08:37:10 EDT
Article-I.D.: westmark.152
Posted: Sat Sep  5 08:37:10 1987
Date-Received: Sun, 6-Sep-87 05:19:12 EDT
References: <2896@psuvax1.psu.edu> <1463@chinet.UUCP> <18171@amdcad.AMD.COM> <1469@chinet.UUCP>
Organization: Westmark, Inc., Warren, NJ, USA
Lines: 25
Summary: Some Modems...
Xref: mnetor comp.sys.att:1158 comp.unix.questions:3902

In article <1469@chinet.UUCP>, randy@chinet.UUCP (Randy Suess) writes:
> 	How do you handle the problems of the 3b2 port drivers 
> 	requiring CD (pin 8) to be hi to dial out, and the needs
> 	of the 3b2 to see CD go hi and lo for proper login/logout/hangup?

This problem exists on other versions of UNIX, also.  The best
solution I have found is to use the Microcom AX/... series of
modems. (Others may also have the feature I like).  These modems
have three options regarding the carrier-detect lead:

	1) CD reports the true state of carrier.
	2) CD always asserted.
	3) CD mostly asserted, but lowered for 1 second on disconnect.

Using option 3, your UNIX system can find CD true and dial out any
time.  It can answer incoming calls and accept logins (we use
uugetty).  If the connection is dropped, the modem lowers
carrier-detect long enough for UNIX to see it, generate a SIGHUP,
and clean up after the session that just ended.  It then re-asserts
CD and dial-in/dial-out operation is restored.
-- 
Dave Levenson
Westmark, Inc.		A node for news.
Warren, NJ USA
{rutgers | clyde | mtune | ihnp4}!westmark!dave