Modem I/O

[Steven G. Madere]

A friend of mine has a 386 AT clone made by a company called MYLEX.
He is running MicroPort's UNIX System V for the 386 (very latest release)
He has been having some problems with remote sessions.  Sometimes, if one
hangs up when not at a login:  prompt the process is not killed and the
next one to call gets a blank screen.  Sometimes the entire system locks
up (no core dump or anything).  Sometimes subsequent attempts to connect
will find a modem which has about a 1/4 second timeout on carrier detect.
The device he is logging in under is called /dev/ttyM01 wherein the M 
denotes the modem control characteristics of the device driver being used.
He is using an internal Hayes compatible half card 1200 Baud modem in the 386.
All switch settings on modem have been checked (DTR off->hangup  DCD follows 
actual conditions, address is COM1)
The following is a mail message which I received from him on that buggy box.
 
 
 
>From bill Thu Jul 28 15:24 CDT 1988
To: steve
Subject: random thoughts
 
 
Steve, why is it that every time....
 
The box is still having problems with the modem.  The night of 7/27 I called
and hung up on the box -- the box went down, the box went down hard.  I was
wondering if you might do some hunting around on the usenet sometime for an
answer (I'll have to check usenet out myself sometime).  This box is also
barfing quite a bit when I do Ctrl-S Ctrl-Q sequences.  Another bizzare
occurance happened today (7/28-Thurs.) when I catted a bin file -- the
terminal settings somehow got really fried, the output to the screen was
in all extended characters, but it could read what I typed in.  So I typed
stty sane, then tput init, tput clear and a host of others, all to no avail.
So, I logged off the system and back on again, and the thing was still wacko.
I tried killing the getty on the console from another console, but the
problem still persisted, strange to me but I suppose there is a good
explanation.
 
 
Any thoughts?
Helpful hints maybe....