RL problem

[utzoo!decvax!ucbvax!menlo70!sri-unix!jeff at UCLA-Security]

From: jeff at UCLA-Security (Jeff Schaffer)
I have an 11/44 with dual RL02's on it and am running DEC's modified V7 on it.
(Dec distribution release date - ~ June 1980)
I am having a very interesting problem occur. The symptom is
that at system boot time I can boot one Unix load module but not
an identical copy of it. The error coming back is a header not found
from the RL02. After some tracing, we found that whether or not the
system would come up was dependent upon where the head on the RL02
is last positioned (where the last block of the load module is).
If the last block is on a cylinder <= 255 (1/2 of the disk),
then everything is fine. If it is on a cylinder => 256, the header not
found errors occur.

I have tried this on 3 different 11/44 systems, so it is not just a bad board
in our system. Has anyone else found this? Is there a design flaw
in the RL controller or a driver mod that I might not be aware of?
Any help would be appreciated.
Jeff Schaffer