modems, getty

[Danny Boulet]

In article <TIME.90Feb6171340 at oxtrap.aa.ox.com> time at oxtrap.UUCP writes:
>
>Finally, if you can not get getty to block on CD, then you can use the
>technique of putting the modem into "quiet" mode, thus avoiding the
>input from the modem (i.e. RING, RING, CONNECT). This is not an
>optimal solution, but it gets the job done most of the time.

When I was setting up my machine for UUCP, I finally had to put my modem
into "really quiet" mode.  I disabled the "RING, RING" stuff, turned off
the "OK" stuff and turned off command echoing.  This ensured that no junk
of any sort would be sent back to my machine by the modem.  Until I did
this, the problems I ran into included:

    - the serial port would get into an echo-enabled mode.  Any character
      sent by the machine would be echoed by the modem which would be echoed
      by the machine which would be echoed by the modem which would be
      echoed by the machine which would consume lots and lots of CPU resources.
    - the getty would read the "RING" or the "CONNECT" stuff as an attempt
      to login and prompt for a password.  Since this wasn't repeatable, I
      was never able to come up with a login handshake sequence to put into
      the /usr/lib/uucp files that would work reliably.

If you're having these or similar problems with serial lines, try convincing
your modem to completely shut up.  It may do the trick.

One of the side effects of this "really quiet" mode was that it was a bit
tricky to use the modem for dialing out since it gave no feedback whatsoever.
A bit of practice and placing the modem where I could see the lights pretty
well solved this problem.