From: compata@cup.portal.com (David H Close)
Newsgroups: comp.unix.xenix.sco
Subject: Modem answer speed
Date: Wed,  7 Oct 92 02:31:20 PDT
Organization: The Portal System (TM)
Distribution: world

I have previously written that I had two customers with problems similar to
Alan's (alan@tree.SAC.CA.US).  Well, one of those turned out to be a simple
error, probably on my part.  Both tty2A and tty2a were enabled, causing the
two gettys to fight for the line.  I guess I'm lucky it worked at all.  But
that was the system which did answer at 2400.  The system which insists on
answering at 1200 has no such easy solution, at least that I've found.  I'm
still looking for further ideas.

This is SCO Xenix 2.3.3.  The problem modem insists on answering at 1200,
even when I call at 2400.  If I switch my call dynamically to 1200 and
attempt to login, the line goes dead after Login:.  That is, my username
is echoed correctly at 1200 but Password: is garbled and no entry is
accepted.  (Disconnect and re-dial allows another try.)  But if I first
send one break, both the Login: and Password: prompts are fine and the
session works correctly, albeit at 1200.  The garbled Password: prompt is
"osS" (fairly consistently).  The modem involved is an internal AT-bus type.

Alan writes that he has had success by hiding the entry in Devices (ie,
making ACU into SUPPORT), as suggested by a net helper.  I just tried that,
but without success.  The modem still insists on answering at 1200.

Several people suggested that Alan and I lock the modem at 2400.  Useful
the next time I visit this site, but, if I try it remotely and the modem
still insists on answering at 1200, I could be locked out!  The only fix is
to explain to a naive user by phone how to access root and change gettydefs.
(Yes, I'd keep a backup.)

On my last visit, I started Kermit at 2400 and caused the modem to out-dial.
That worked fine.  So at least the output side of 2400 works.  I have asked
the on-site user to start up Kermit at 2400 (which can be done from a normal
account), then tell me what appears on the screen when I call.  The modem
answers at 2400 and my typing appears correctly on his screen.  So the input
side of 2400 works also, if Kermit has the line.  I think this rules out the
possibility of a broken modem.

As I understand it, most modems in this speed range answer at the lower of
the caller's rate and the rate at which the computer last sent the modem a
command.  So the Dialers entry should cause the last command to the modem
to be at 2400, when the previous call disconnected and the line was re-
initialized.  I've tried both hayes2400 and dialHA24.  If the modem were
external, I'd put a monitor on it and check.  As it is, I am reduced to
inductive reasoning (guessing).

And, although the modem answers at 1200, getty appears to think the connect
speed is 2400.  It takes a break to cycle it down to 1200.  This says to me
that getty believes the gettydefs entry.

Is it possible that Kermit asserts some signal that getty doesn't?  Is
there any other program which could be sending something to the modem?
(I've checked the accounting logs without noticing anything.)  Is there
any reason why hayes2400 or dialHA24 wouldn't send at 2400?  Just for the
record, gettydefs is stock, /etc/ttys says "13tty2A", Devices says
"ACU tty2A - 2400 hayes2400 \D" or "... dialHA24", and Dialers is stock.

If I had any hair left, it would be coming out now!

 Dave Close - Compata - Stockton, California - +1 209 467 8255 ("209-install")
  dave@compata.attmail.com | compata@mcimail.com | dhclose@alumni.caltech.edu
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