What is this panic?

[irwin at uiucdcs.UUCP]

We have 7 Vax-750s. Ours are all at Rev 3 CPU. We have the exact panic
you have described on 3 of the 7 quite frequently. We have a Ramtek
on one that can cause a crash from time to time, but this is a different
bug. We know that if the CPU were at Rev 7 the Ramtek bug would go away.

We have wondered if our machines were at Rev 7, if the panic bug would
disappear. Yours is at Rev 7 and do it, so that answers the question.
What causes it, still do not know.

Our disks are on CMI controllers, some CDC 300MB, some Eagles, some CDC 80MB.
Two of the 7 have hdwr floating point, no two of the seven are configured
alike.