24 Feb
2021
24 Feb
'21
9:26 a.m.
Yep. I actually had one. The lid flew off the top of it while we were
driving it back from Eastern shore to Baltimore on Rt. 50 but the rest
of it was intact. Very different MBA controller from an RM02/03.
Unfortunately when Doug closed up the storage place someone swiped MC
from there before I could pick it up, and at the same
time the RP07
vanished. I'm guessing that the 07 was junked as MC has
resurfaced in a
museum.....
CZ
OOOOhhh, the RP07!? I have stories about that drive!
It was a Burroughs mainframe drive they reprogrammed for DEC.? It had a
number of issues.
The worst one was that due to some microcode bugs, it was possible to
trash an occasional track descriptor record. When a bad TDR was read,
the drive totally locked up, you had to cycle power to reset it.? VMS
recovered from it quite gracefully, however.? They finally fixed it, it
required replacing about 10 boards.? Then, there was a procedure to
rewrite all the TDRs.? The DEC FE assured me it would not touch user
data.? Well, after running the procedure, it came up as a blank disk!
YIKES!? A quick check at the binary level showed data was still on the
drive, but the RMS-11 home block had been overwritten.? Well, I had a
program that could examine the home blocks, and I knew where to find the
backup home blocks.? So, I hacked that program to copy the backup block
to the main one, and then change the checksums to agree.
The other issue is the voice coil could suck dirty air in during long
seeks, so they had ti replace the HDA and put a filter over the air
exhaust from the voice coil.
Well, just the guts inside an RM05, that was a
9762 drive relabeled by DEC.
Jon
Yes, the TM02 and TM03 formatters allowed MASSBUS
to connect to Pertec
drives, but I don't think you could run a tape drive and a disk drive
on the same MASSBUS channel anyway. Wonder why, technically the
MASSBUS cable is just an extension of the Unibus, so it shouldn't
matter much what combination of cables you used. Maybe they just wrote
different drivers or something.
MASSBUS was not anything like a UNIBUS, it was a lot closer to an IBM
channel bus and tag cable.
Anybody
knows if there was conversion kit to equip CDC 9762 and 9766
type SMD drives into MASSBUS drives much like the TU81 could be
turned into a TA81 (SDI)?