Well, I got a lot of responses to the problems I was having
with a Boca 14.4 modem. Here's my original post (shortened
> I am having a problem with a Boca modem. I don't seem to
>be able to set hardware carrier detect on device ttyd0.
Well, I followed all the instructions that I got, one at a time.
Nothing I tried worked. I took the modem home and was also
unable to get it to work from there (I set it up exactly like the
current modem I run from home - no dice). THe phone line to our
site is often interrupted by an operator which makes debugging
a modem even more difficult. I *am* able to get a 2400 baud
modem working no problem. Perhaps the trouble is with the modem
itself. Alas, I may never know. Our lab will not be buying another
modem as long as our phone service is so shaky.
Here are the relevant replies I
received. Many had good points to make, so I will post them
in hopes that they will help someone else. Cheers, and thanks
to everyone who gave this some time.
From: Robert Sargent <sargent@SGT.COM>
You shouldn't put the /dev/cua0 in /etc/ttytab.
From: email@example.com (dave)
First, get rid of the "cua0" entry that you have in the /etc/ttytab file
Put only dial in devices in the ttytab file.
Also, change permissions on /dev/ttyd0 to 666, so anyone can read the
From: firstname.lastname@example.org (Steve Harris)
The word "remote" is not legal in /etc/ttytab (a device is remote
_unless_ the "local" keyword is specified). In my experience, when
init sees the word "remote", it _ignores_ the rest of the line.
Do you have a copy of Syed Zaeem Hosain's excellent document on
connedting modems to sun workstations? His email address is
(Syed turned out to be valuable source of information and his paper
was very thorough. A good read)
From: "Haiquan Dai" <email@example.com>
You missed one more thing.... set the following and reboot the machine.
From: grevemes@VTC.TACOM.Army.Mil (Steven Grevemeyer)
fix the computer<->modem bps rate
at the highest common speed - for the sun thats 38.4Kbps. The modem
will handle the buffering for the connection speeds. This allows only
a single entry in /etc/gettytab for that speed.
> <7> Attempted to turn on hardware DCD for devices marked remote using
> ttysoftcar -a:
When this happened to me I just didn't do it anymore. 8-)
with the fixed bps rate scheme described above it isn't really necessary,
the only major problem is that the hardware flow control for most
sun's is broke. You should put a "stty crtscts" entry into any startup
files which will need to use the modems.
From: kene@Eng.Sun.COM (Ken Erickson)
It looks like ttyd0 is already open (the getty may be running).
Be sure you have it 'off', kill any getty or login that's running,
then issue ttysoftcar -a.
Then, turn the port back on.
If you are running Sunos 4.1.x, you need the jumbo tty patch. I'm
not sure there is one yet for Solaris 2.3, but no factory default
Sun system knows how to handle hardware flow control. Also, they
tend to lose track of ^S/^Q signals and hang the serial line until
you power cycle. The patch fixes this as well.
From: firstname.lastname@example.org (UUCP owner)
On my Sun3/50 running SunOS 4.1.1_U1 I've never managed to
get ttysoftcar to work right with the -a flag. Instead this
is what I use that works for me:
/usr/etc/ttysoftcar -n ttyd0 > /dev/null 2>&1
Andy Mitchell * email@example.com * System Administrator UF NMR Lab
firstname.lastname@example.org * http://ufnmr1.health.ufl.edu/~afm
There is no difference between theory and practice - in theory.
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