8 Nov
2013
8 Nov
'13
11:18 a.m.
From: Jules Richardson
Sent: Friday, November 08, 2013 9:07 AM
If I remember right the RA81 is the complete cabinet
(the actual
HDA inside is called something else), but the RA72 is just a drive,
correct?
No, it's called "the RA81 HDA". We had 6 RA81 drives in 2 low-boy
cabinets at LOTS, with redundant HSC50s and an SC008 putting them
together with 3 DEC-20s and a System Concepts SC-30M on a CI network.
With an MTBF of 6 months, DEC Field Circus replaced an HDA roughly
every month until the manufacturing error was discovered[1]; our FE
sincerely hated those drives.
Rich Alderson
Vintage Computing Sr. Systems Engineer
Living Computer Museum
2245 1st Avenue S
Seattle, WA 98134
mailto:RichA at LivingComputerMuseum.org
http://www.LivingComputerMuseum.org/
[1] It turned out that the "latex" gloves used by clean room workers
in the assembly of the HDAs were permeable to skin oils, and the
platters were ending up with occasional fingerprints on them.
Once that was corrected, the drives were much more stable in the
field, but the damage to their reputation was insurmountable.