DTR failure on DZ-11 ports

[John Bruce Zuckerman]

The university of Oregon Computer Science Dept. is experiencing the
following difficulty with its 4.3 BSD systems and we are soliciting
advice from others who may have a solution or explanation.

We are running several VAX 11/750's with attached DZ-11 serial
interfaces.  On very infrequent occasions, the DTR signal fails to be
raised on one or more of the DZ-11 ports.  This prevents users from
logging in on the affected ports.

The pattern of failure appears to be unpredictable.  Sometimes only a
single port is affected at a time, and apparently any of the ports of
our system may become the failing port.  At other times, more than one
port is affected.

We can treat the problem symptomatically by running a program which
forces the raising of the DTR signal on the affected port, however,
this is of only transitory benefit.

If you have experienced similar problems with your DZ-11 device(s), or
know of a permanent fix to the problem, please respond by mail.

John Zuckerman			UUCP:  ..{hp-pcd,tektronix}!uoregon!johnz
Systems Staff			CSnet: johnz at cs.uoregon.edu
University of Oregon, CS Dept.