Update from 4.7 to 5.3 is not stable. After about a day ,
the disk structure is courrupted. We are using an area in
the QBUS address range beginning at 256K, length 64K as
private memory.
The Answer is:
Disable the use of the Q-bus memory and see if the system operation
stabilizes.
If the Q-bus memory is not (correctly) coordinated through the Q-bus
allocation routines documented in the device driver manual, all manner
of odd corruptions are possible.