Subject: Re: unexpected machine checks
To: None <>
From: Andrei A. Dergatchev <>
List: port-alpha
Date: 01/13/2001 00:51:45

> Unexpected Machine Check


>         vector  = 0x660
> Is this indicative of bad memory?

Yes, very probably. There was a case (for pc164) when it appeared
to be a problem due to bus (you could look in archives).

>  How would I go about
> finding out what these machine checks mean?

Machine checks are of four (4) types, as in the following table:

Code      Reason                  Example or Common Cause
====      ======                  =======================

620     System Correctable        correctable errors in the memory
                                  eg single bit ECC errors, detected
async to
                                  processor execution

630     Processor Correctable     correctable cache and TLB errors,
                                  internally by the processor

660     System Uncorrectable      unrecoverable memory errors

670     Processor Uncorrectable   unrecoverable cache or TLB errors, or
                                  read of a non-existent I/O space

> Maybe my reliability problems burning CDs and these
> machine checks are related?  I think I had better stop
> trying to burn CDs until I get this sorted out... I've
> destroyed 5 today.

Perhaps it is just any load that will cause problems.

> Thanks,
> Nick Maniscalco