connecting 2400 modem to 3b2/310 in auto-answer

[Leslie Mikesell]

In article <16215 at oberon.USC.EDU> ami at kodkod.usc.edu () writes:
>I am trying to connect a 2400 baud Hayes-compatible modem to
>a 3b2/310 running 3.2.2 -- and I am having a problem:

[... problem is at 2400]
>To start "getty" I have a script that (1) talks to the modem over the port (get
>it into answer-mode, cancel echo, etc.), (2) edits /etc/inittab to respawn
>"/etc/getty 2400 /dev/ttyxx" and (3) call "telinit q".

This is probably caused by your modem spitting out a "CONNECT 2400" message
at 1200 baud or whatever speed you used last.  This causes getty to change
speeds and as you have noticed, it requires a "break" signal to cycle once
you are switched to a lower speed than the connection.  If getty is set to
a higher speed than the connection, almost any character will give the effect
of a break signal.

Anyway, the solution is to forget the tricks you are playing with getty and
use /usr/lib/uucp/uugetty instead.  Also, set the modem so that it only
provides "carrier detect" when carrier is present.  This wil require you to
add a ",M" to the end of the device name in Devices and add a "\M" to the
beginning and a "\m" to the end of the Hayes dialer script in Dialers to allow
dialing out without the fake carrier. 
Most modems don't raise carrier until after they have sent the "CONNECT"
message, so uugetty won't see it anymore.  These tokens were added in SysVr3.1
and should be documented by now - at least in the release notes if not the
normal place.  The Dialers and Devices files should have comments explaining
them in any case.

Les Mikesell