Xref: utzoo unix-pc.general:1654 comp.dcom.modems:2921
Path: utzoo!attcan!utgpu!watmath!clyde!att!osu-cis!n8emr!uncle!jbm
From: jbm@uncle.UUCP (John B. Milton)
Newsgroups: unix-pc.general,comp.dcom.modems
Subject: Re: Need tty000 modem help
Message-ID: <417@uncle.UUCP>
Date: 12 Nov 88 05:32:32 GMT
References: <4242@pitt.UUCP>
Reply-To: jbm@uncle.UUCP (John B. Milton)
Distribution: na
Organization: U.N.C.L.E.
Lines: 47

In article <4242@pitt.UUCP> anthony@pitt.UUCP (M. Anthony Kapolka 3) writes:
[describes modem setup]
>When I set it up (via /etc/inittab) with a getty, everything seems fine.
>When someone calls in, however, the modem picks up the phone and then
>promptly hangs up on the caller.
>
>If the modem receives a call without being connected to tty000 (ie the
>serial cable unplugged) it answers just fine.  If I then plug in the
>cable (with a getty sitting on the port) everything then works.
>(Gosh, maybe all I need is a trained monkey!)
When init spawns the getty, it hangs on opening the line until it gets CD
from the modem. The getty's open then succeeds and the getty wakes up. If the
cable is flaky or the CD line is floating, or something else causes CD to jump
or go away, the getty gets a SIGHUP and the getty dies. One way around these
problems is to create another set of /etc/gettydefs lines:
remove HUPCL and add CLOCAL. This is getting ugly, but whatever works. You 
may need to check /etc/profile to make sure the line doesn't get dropped by
a stty there.

[describes cable fudging]
>Any help would be appreciated... I don't have a break out box and this
>has just gotten too strange for me.  Surely someone else has had this 
>problem.
With one of those cheapy 5 LED jobs, you can diagnose 90% of all problems.
These are also good at reflecting signal strength in the brightness of the LED.
Like UNIX, the simplest tools are the most valuable.

[describes OS version]

>Also, does anybody out there have an auto-bauding getty working?

I have a very modified modem-ctl (was posted to the net) called prtty. It does
autobauding by letting a talkative modem TELL it what the speed is:

CONNECT
CONNECT 1200
CONNECT 2400

It then exec()s a "getty -h line speed". I have had this program out on beta
test for a while, with only minor complaints. I want to re-write it to be 
state driven, but I should post it as is first since I've got so many irons in
the fire as it is.

John
-- 
John Bly Milton IV, jbm@uncle.UUCP, n8emr!uncle!jbm@osu-cis.cis.ohio-state.edu
(614) h:294-4823, w:764-4272;  MS-DOS is a beautiful flower that smells bad!