17 Jan
2023
17 Jan
'23
8:54 p.m.
Am Dienstag, 17. Januar 2023 um 01:20:22 MEZ hat Chuck Guzis via cctalk
<cctalk(a)classiccmp.org> Folgendes geschrieben:
On 1/16/23 12:40, Paul Koning wrote:
On the CERL PLATO system at U of Illinois, around
1977, we had 20-ish
844-21 drives, and maybe a few 844-41 as well. Those were roughly the
same as the DEC RP04 and RP05 drives, same pack and track count.
Different sectors, though; 322 12-bit words per sector. Those are 3600
rpm drives, linear voice coil head actuator, dedicated servo surface.
The details of the format was handled in a sort of microcoded bit
handling engine, one of two engines in the programmable controller
(7054). I actually have the source code still around, and the manual
for that beast also still exists.
Most of our customers from that time had all
of the drive farm as
well as the unit record equipment on MACs. (Predates Apple--Multiple
Access Controller). We kept Spence Preston busy... :
We had a 1311 on a CADET. Slow, but better than the alternatives (cards
or paper tape). Monitor IID, IIRC. Work cylinders were 0-25, IIRC.
No real file system, just DIM entries. I don't recall what options had
to be installed on a CADET to run Monitor, but I think indirect
addressing was a requirement.
My favorite was the CDC 6603/Bryant 4000. That bugger was engineered to
leak oil--it even had plastic jugs inside to collect the drippings. My
fondest memory was watching a COMSOURCE operator run to refill a 501
printer, hitting the Bryant oil patch and falling flat on his back...
Paul, Chuck, the hydraulic actuator-driven disk systems surely bring maintenance
and related issues to another level and stories :) Thanks!
From what I see at least by the return on our list, there don't seem to be, for
example,
servo writer and disk plattern mechanical alignment tools still around - at least to the
knowledge of the cctalk list members.
I wonder, if the CHM could have any additional knowledge about this and I will contact
Al Kossow out of curiosity regarding this.
Anybody aroundhere who used drives in the last 10 years to read multi-platter disk
packs successfully?
At least the CHM did so to read single-platter disks and archive software (thanks to the
great
videos, curious Marc!), but I don't know if they tried to work with multi-platter
disks.
I recall that the Jim Austin Computer Museum tried to get a 9766 300MB disk drive up and
running, but it suffered a head-crash after a few hours and they decided not to go any
further
down this road...
Greetings,
Pierre
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