6 May
2005
6 May
'05
4:57 a.m.
On Thu, 5 May 2005, Lee Courtney wrote:
This looks a lot like a development system we'd
have in the RTE Lab in the
late 70s/early 80s. 7925s were 120MB removeable packs, 7920s were
100MB(IIRC). Across a string of several drives I remember 7925s having
fairly frequent head crashes - maybe on the order of one every 6 months or
so.
The 7920s were 50Mb. The head crashes had a lot to do with how clean
your computer room was. I used to work for a company doing 3rd party
maintenance on HP3000 systems. We had a couple of customers who installed
a humidifier in their computer room, unfortunately the type that left a
fine white powder residue. I ended up replacing multiple heads in the
7925s and practically disassembling them to clean them up. The white
powder goes straight through the foam filters.
As I recall, the usual cause of head failure on the 7920s and 7925s was
one of the wires to the head breaking. They could be replaced and aligned
without too much pain, with an alignment pack and a scope.
Mike Loewen mloewen at cpumagic.scol.pa.us
Old Technology http://ripsaw.cac.psu.edu/~mloewen/Oldtech/