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