4.2bsd on vax750

[R.YING]

I got this message on the console while running 4.2bsd
on a 750, it happens quite frequently, but I wasn't able
to catch the cause of it, does anyone else has the similar
problem?  If there was an article about fixing this, would
someone forward me a copy?  Thanks in advance.

---- message on console:

Oct 12 09:10
write timeout 8002584a
panic: wtimo
trap type 2, code = 0, pc = 80000fa2
panic: Reserved operand
trap type 2, code = 0, pc = 80000fa2
panic: Reserved operand
trap type 2, code = 0, pc = 80000fa2
panic: Reserved operand
trap type 2, code = 0, pc = 80000fa2
panic: Reserved operand
trap type 2, code = 0, pc = 80000fa2
panic: Reserved operand
trap type 2, code = 0, pc = 80000fa2
panic: Reserved operand

.... (system reboots itself)

R. Ying		{allegra,dual,houxm}!nv750!ying