RA-81 reliability (was Re: ebay bid on dec rack)

From: Huw Davies <Huw.Davies_at_kerberos.davies.net.au>
Date: Thu Mar 27 00:49:00 2003

At 06:54 AM 26/03/2003 -0800, Ethan Dicks wrote:

>There was a notorious problem with a formula change with an adhesive.
>I don't recall the HDA rev letter, but drives from the wrong batch
>would fail in record time. Big scramble for DEC to plug the gap.

I can certainly confirm that there were significant problems with glue
"migrating" onto the platters in RA81s. At the site I was working at in
about 1982 we ordered two RA81s and suitable controller to augment our
storage - we had an RM80 as system disk and two RM03s for user data - these
were the good old days! These were some of the first RA81s delivered in
Australia - I like to say that we had the first two RA81s in Australia
along with about 10 of the next few shipments as well. It got to the stage
where my Field Service engineer and I could replace an RA81 HDA in about 15
minutes.

>I think I've seen one drive die due to electronic failure, ever.

The most entertaining RA81 failure we had (glue induced failures excepted)
was when the drive select switches on drive 1 failed. The controller
detected duplicate IDs and spun _both_ RA81s down. Took a long while to
work out why every time the second drive was powered up, the first would
spin down....


Huw Davies | e-mail: Huw.Davies_at_kerberos.davies.net.au
Melbourne | "If soccer was meant to be played in the
Australia | air, the sky would be painted green"
Received on Thu Mar 27 2003 - 00:49:00 GMT