Subject: Re: Peculiar serial behaviour
To: The Great Mr. Kurtz <davagatw@mars.utm.edu>
From: None <sparta@imsa.edu>
List: port-mac68k
Date: 04/10/1996 20:22:18
Thus spake The Great Mr. Kurtz:
> 
> On Wed, 10 Apr 1996, Ken Nakata wrote:
> 
> 3 Questions:
> 
> 1. When the serial port goes ballistic, does the console still behave
> normally (this, of course, only applies to systems running with the
> internal keyboard/display as the main console and a separate serial
> login normally)?
Sure.  ttye0 is just fine with it the whole time.  I can login and logout at
will.

> 
> 2. Does disconnecting the serial connection and reconnecting it either
> reset the connection back to a login prompt or at least start things
> running again?
No.  Disconnect and reconnecting, swithcing programs, the whole bit seems to
have little effect on the problem.  It only goes away when I quickly drop to
single-user and come back up again.  Then, I have a login prompt on tty00 and
i have about 30 lines more grace.

> 
> 3. Have you checked to see if NetBSD is receiving handshaking signals
> such as control-S's and control-Q's, and if so, checked to make sure
> it's not just missing a control-Q or a CTS or whatever (test by hitting
> control-q)?  I doubt it's something that simple, but if it were, it
> would simply be minor loss, and not something drastic like a complete
> crash.
I tried a number of different flow control and carrier detect configs on the
terminal side with similar effects.  I beleive getty is supposed to handle
this anyway, but my feeling is that the problem is too chronic and predictable
to be soemthing on this order.

> 
> In other words, is NetBSD crashing or is the serial interface getting
> blocked somehow (or not being serviced properly or being intentionally
> paused)?
Oh, its definitely an issue with the serial driver.  The whole time, you can
telnet into the machine and do anything you want as normal.  When its forzen,
the believes there is still me logged into the serial prot (it won't let me
kill the shell in fact) .... it is as if the characters are being suddenly
buffered up or put somewhere.  The system at a topical level seems to be
convinced it is still connected.

> 
> BTW, forgive me for my ignorance, as I've never used dt.  Will dt
> run over a serial console or is it too graphically oriented?
Sall right.  dt is designed mainly (exclusively, actually) for graphical
consoles.  It takes advantage of some of the mac graphics capabilities and
supports virtual consoles.

> 
> Thoughts?

 certainly don't have enough.  What I need is an infusion of intelli9gence or
 a stroke of genius or two :)

 Gene

--
Gene Skonicki           "Sometimes I get so tired of this thing called life.
sparta@imsa.edu          I'm not scared of dying; I'm afraid of going through
			 this thing twice." -Poy Dog Pondering