[TUHS] flaky webster or sigma WQESD4 and RQD11 controllers on KA650???

[Robertdkeys at aol.com]

I upgraded my MVII KA630 critters to MVIII KA650
critters.  The disk controllers in them are the
old Webster or Sigma WQESD/4 and SCD-RQD11/EC
(same boards).  When I upgraded the cpu/ram on
one of the machines, and tried to use the onboard
formatter rs232 port, the port gave crazy spaces
and backspaces continuously after the initial
boot signon msg into the controller formatter
prom.  Changing it to a DQ696 controller and the
problem went away.  On a second machine, with
KA650, it has a tendency to give uda controller
initialization errors about 50% of the time when
booting.

Is there an endemic problem with this style 4
port controller running too fast with a KA650
compared to a KA630 cpu?  It sure feels like
that.  It would be a bummer to have to use the
slower cpus on these machines....(:+{{.....

Anone else run into these kinds of problems?

Ultrix seems to handle it better than Tahoe.
It might be speed in the hardware and slight
differences in drivers?

Any suggestions or thoughts appreciated.

Thanks

Bob