From: news@alderson.users.panix.com

=?UTF-8?Q?Arne_Vajh=C3=B8j?=  writes:

> On 12/1/2025 6:56 PM, Rich Alderson wrote:
> > =?UTF-8?Q?Arne_Vajh=C3=B8j?=  writes:
> >> On 12/1/2025 1:02 PM, Scott Dorsey wrote:
> >>> There are many devices that should be preserved in working condition so
that
> >>> new generations should see how they worked when they were new and
experience
> >>> them working.  The RA81 should be left in the rack broken, so that new
> >>> generations can see how they were when they were new.
> >
> >> RA81's and RA82's on a 8650.
> >
> >> The RA82's were okay, but the RA81's crashed frequently. DEC field
> >> service knew that site very well.
> >
> >> I have been told here that there were a manufacturing problem with
> >> RA81's and when the problem got fixed they stopped crashing all the
> >> time.
> >
> > You've got the RA81 and RA82 backwards.  We had RA81s on a CI cluster at
> > Stanford, and they were pretty solid.
> >
> > RA82s were not available for the 36 bit systems, but we heard about them
from
> > our DEC FEs.
>
> I could easily remember it wrong - it has been a long time.
>
> But a search in c.o.v confirmed that it was the RA81's.
>
> 2003 post:
>
> 
> The problem with the RA81's wasn't that the drives were really flaky --
> there were some early data and noise problems ECO's out under warranty
> early on -- but that the glue that held the HDA filter was substituted
> without a close look at the specifications of the glue.
>
> The substituted glue on HDA's at Rev F (IIRC) would liquify at warm
> temperatures and flow to the bottom of the HDA and crash head 13
> into the bottom platter every time.
> 
>
> 2021 post:
>
> 
> The early RA81s had a problem where the heads would "unglue" from the
> actuator and totally trash the disk.
>
> DEC actively hunted out and replaced those original drives. The
> replacement RA81s were good and ran forever.
> 

Odd.  That's exactly what I remember about the RA82!

--
Rich Alderson					  news@alderson.users.panix.com
      Audendum est, et veritas investiganda; quam etiamsi non assequamur,
	  omnino tamen proprius, quam nunc sumus, ad eam perveniemus.
									--Galen

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