Scrapping 2x RA81 + parts, 4x RA72 - test-drb@ccmp.vtda.org

10 Nov 2013

On 11/10/13, 10:00 AM, Rich wrote:
...
   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. I tried to give the Living Computer Museum parts from
a RA81 that I
disassembled.  I also tried to give it away here and within the local SRCS
group. I ended up giving the  to RePC, a local computer recycler that has
a small museum in one of their stores.  I still have another RA81 and two
RA82s.

The HDA is the sealed assembly with the platters and heads and was
sometimes (often?) replaced separately from the rest of the drive. The
HDA is installed in a chassis that forms the rest of the drive and mounts
in a standard rack. The drive motor, the logic boards, front panel switches,
power supply, etc. are inside of the chassis, outside of the HDA.

alan