Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!ukma!nrl-cmf!ames!pasteur!ucbvax!ucdavis!ccdan
From: ccdan@ucdavis.ucdavis.edu (Dan Dorough)
Newsgroups: comp.bugs.2bsd
Subject: Re: rx, dz, kermit
Message-ID: <3056@ucdavis.ucdavis.edu>
Date: 14 Sep 88 03:30:38 GMT
References: <270@marque.mu.edu>
Reply-To: ccdan@ucdavis.edu (Dan Dorough)
Distribution: na
Organization: University of California, Davis
Lines: 27

In article <270@marque.mu.edu> dennisf@marque.UUCP (Dennis Flaherty) writes:
> On my 2.10 system, I have (among many others) an RX02 and a
> DZ11 mux.  [...]  Although the
> dz driver attaches, and the lines are in /etc/ttys, I can't
> get the lines to work.  
> If I try an echo >/dev/tty00, I have to hit ^C and I get
> a "can't create" error.  A listing of "ps asux" shows that
> unlike my DL11 lines (which work), my DZ11 lines all have
> a ? for the tty of their gettys.

these symptoms sound like modem control in action.  the DZ11
honors modem control signals.  when an open() occurs on a dz
port, the open() hangs until the dz gets carrier.  that's why
your "echo" hangs, and it's also why getty shows "?" for tty;
it hasn't gotten the device opened, so the controlling tty
(that ps displays) isn't established yet.

if you are using your DZ11s as hard lines, you need to bring
in more than just pins 2, 3, and 7.  you also need DTR going
out and CD coming in (i don't have the pin numbers handy).
some folks just jumper those inside the DB25 connector, others
actually carry them from the terminal so that when the terminal
is turned off the session gets a SIGHUP.  if you are using
your DZ11s as dialup lines, of course those cables should
carry modem control signals between the dz and the modem.

--dan dorough, ucdavis systems programmer