Re: FYI: Disk overruns.

[Mabry Tyson <TYSON@WARBUCKS.AI.SRI.COM>]

We have occasional problems such as you described.  Despite what you
say, it certainly sounds suspicious that you are right about what you think
was the solution.  Unless you have a bad I/O paddle card, I rather doubt
that anything going on with the disk will affect the net.  Of course,
maybe the CE changed something else on your CPU (I/O, I/O paddle?) at
or around the same time as the change to the disk.

When we've had such problems it usually turned out to be bad I/O cards or bad
transceivers (or transceiver connections).  I even have had one where the
transceiver cable was partially pulled loose from the bulkhead.  Also, these
machines seem to have occasional problems that are solved by reseating the
boards.  (Ie, what may have seemed like irrelevant activity may actually have
been your solution.)

When our CE believes he has a suspect board, we usually put it back in to
see if the problems come back.  I'm curious if that was done with the
disk boards in your case?  Without that, my theory of why the disk problems
were causing network problems is "They weren't!".  (Of course, the disk
problems could have been caused by bad boards on the disk or they could have
been caused by the net problems which in turn had a different cause.)

I presume you looked at the net statistics in the Peek window to see if that
host (versus other hosts) had more or less bad packets.

Did your CE do the recommended/required adjustments to the disk cards after
putting them in?  It's rather obscure in the Eagle manual but in section
14.2 (Adjustment of Servo Circuit), it says "After changing the DE or ...,
only "Dynamic Adjustment" is needed.."