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From: kathy@bakerst.UUCP (Kathy Vincent)
Newsgroups: comp.sys.att
Subject: Re: How do you get the 3B1 serial port to respond to BREAK?
Message-ID: <862@bakerst.UUCP>
Date: Thu, 20-Aug-87 16:05:06 EDT
Article-I.D.: bakerst.862
Posted: Thu Aug 20 16:05:06 1987
Date-Received: Sat, 22-Aug-87 12:26:57 EDT
References: <232@amanue.UUCP>
Reply-To: kathy@bakerst.UUCP (Kathy Vincent)
Organization: I haven't a clew ..., Winston-Salem, NC
Lines: 70
Keywords: BREAK getty change baud rate

In article <232@amanue.UUCP> jr@amanue.UUCP (Jim Rosenberg) writes:
>OK, I give up.  How do you get a getty on /dev/tty000 to change the baud rate
>in response to a BREAK?  I have a new 3B1 and would like to put an external
>2400 baud modem on the serial port.  I have folks dialing me with 1200 baud
>modems who don't have 2400, but don't have a separate line for the two baud
>rates.  I changed /etc/gettydefs so 1200 goes to 2400 next and vice versa.
> ...the 3B1 would not toggle baud rates when sent a break no matter what
>I tried.  It works fine as long as I don't try to change
>baud rate.
>
>Paul Homchick (cgh!paul) is in exactly the same boat.  I tried uucp'ing to
>his system with a 2400 baud modem on the serial port, and she wouldn't change
>baud rate from 1200 to 2400.  The same L.sys entry expect-send sequences *do
>work* when I uucp to maxepr, which has a 2400 baud modem starting off at 1200
>on an *expansion port*.  Paul tells me Kathy Vincent had the exact same problem
>and finally just gave up.  (Any news on that Kathy?)


Well, let's don't say I gave up - let's just say I put the problem
on hold.  How's that?  :-)  

I didn't know Paul was having the same problem.  And I hate to admit
this, but it hadn't occurred to me that one of the reasons why the
*same modem* I have and the same dipswitch, software switch, and gettydefs
settings I'm using on bakerst are working on Ken Brassler's machine (maxepr)
*and* Gary Smith's machine (ethos) might be because they're using their modems
on expansion ports and not on the RS-232 port.  Ah.  OK.  I feel a little
better now.

And actually, I had two problems.  The second problem was that,
when I tried calling out on the modem (AT&T 4024), the modem did
not appear to be sending connect codes the *first* try.  In other
words, I'd make a uucp call to ethos and watch the diagnostics.
Everything proceeds just fine - up to the point where the system is
waiting on the connect code from the modem.  If the call connected,
I'd hear the other end answer, but no code appeared on the screen,
and everything just hung.  Finally uucico would time out and try
again, and the second time, lo, the code arrived just as it was
supposed to.  Now.  I thought that might be the modem, but apparently
it wasn't:  I recently received a new test version of HDB, and that
problem *seems* to have disappeared, except for the very first call
I make after connecting the modem to my voiceline.  (I use the modem
occasionally for outgoing calls, but I'm not committing my dataline
to it until I know everything is working.)  I can't say I've tested it
extensively enough that I don't still hold my breath when the 
remote end connects.  [ Note: Sorry, but the HDB isn't available -
yet? - for distribution. ]

Gary and Ken both helped me a lot with testing things right after
I got the modem and before I set up this version of HDB.  More
recently when I played with it, Larry Lippman (kitty) called in
with cu.  The modem was set to answer at 2400, and gettydefs entries
pass off from 2400 to 300 to 1200 - this time around.  When Larry
called in at 2400, everything was fine.  But when he called in at
1200, he said that the breaks were, in fact, changing the speed
(or *some*thing anyway) - but to WHAT speed, he couldn't figure,
because nothing intelligible ever came thru, no matter how many
breaks he sent.  We didn't have time to play with it a lot, so I
didn't get into changing the 2400-300-1200 sequence - and I
have to say I don't really think that's going to solve the
problem anyway:  When Gary and Ken and I tested before, the speed
at which the modem answered didn't make any difference, nor did
the sequence in gettydefs.

That's the news - such as it is.  If someone gets this one
figured out, please post to the net or send mail!


Kathy Vincent ------> Home: {ihnp4|mtune|codas|ptsfa}!bakerst!kathy
              ------> AT&T: {ihnp4|mtune|burl}!wrcola!kathy