4.2bsd questions

[ttang.uci-750a%rand-relay at sri-unix.UUCP]

I am in the process of installing the 4.2bsd system.  After building our
testing system and bring it up, I frequently get the following message
at the console:
	mcr0: soft ecc adddr 90c syn 73(or another number)
It seems that there is a soft error occurred at the memory controller.
I would appreciate any of your help if you could provide
me any information about this error and would be really helpful if you
could send me a fix for that or give me a pointer to where i can get the
appropriate info.  Thanx in advance.

/ttang
Arpa:ttang.uci at Csnet-relay
Csnet:ttang at uci
Uucp:ucivax!ttang
P.S:I do not have enough time to dig into the kernel to find out about
this error yet.