4 Jul
2025
4 Jul
'25
11:07 a.m.
On 7/3/25 21:28, Ethan Dicks via cctalk wrote:
On Thu, Jul 3, 2025 at 4:19 PM Wayne S via cctalk
<cctalk(a)classiccmp.org> wrote:
We had a TU77 on a VAX 11/780. (Should have waited for the
TU78.) Anyway, the early ones had a bad heat problem.
DEC added a rack of boxer fans to the rear door that
exhausted air over a heat exchanger to cool the bearing
air. This greatly helped, but there was still an issue when
tape was running fast through the drive, like for backups.
The tape head got hot and the tape would start sticking to
the scraper blades and head.
Otherwise, it was a fine drive. Made bu Pertec, I think the
T1000 model.
Jon
Yes, stats are kept about issues.
Someone should look at the stats and start to investigate when there’s a lot of failures
with the same issue. Explicit instructions should be sent to field engineers to take extra
steps to document what they found and how it was resolved, and report their conclusions
back to the investigation leader.
I remember the DEC-20 at Ohio State. It had a
TU77 tape drive. This
was back in the days of paper Operator Logs. One day, it went like
this:
09:23 TU77 catches fire
09:24 TU77 puts itself out
09:35 TU77 won't load tapes, Called Field Service.
When they called, the convo went something like, "you have a TU77 on
fire? We'll be right out." No additional questions. FS Engineer
comes out with one satchel, opens the tape drive, pops out one board,
pops in a replacement from his satchel, and the drive comes back to
life.
Clearly not his first barbeque.