12 Apr
2024
12 Apr
'24
7:04 p.m.
On Apr 12, 2024, at 2:28 PM, Paul Berger via cctalk
<cctalk(a)classiccmp.org> wrote:
On 2024-04-12 2:45 p.m., Christian Kennedy via cctalk wrote:
Some of the earliest magnetic storage was mechanically simple: magnetic drums. Nothing
moving apart from the spinning media, and quite fast. Fixed head ("head per
track") disk drives are a variation on that theme, DEC had some that were successful
for a while.
I remember a concept for a very fast magnetic storage system that didn't become a
product, as far as I know. The scheme was to build a large array of heads, using
IC-manufacturing type techniques, and mount that array in contact or near-contact with a
flat rectangular magnetic plate. The plate (or the heads) could move a small amount in
one direction. The idea was "head per sector", with the mechanical motion
scanning the sector across the head. Given something like piezo-electric actuators it
would have been quite fast.
There's a neat document in the CWI archives, a course on computer design from early
1948. It has a section about memories, well before core memory was invented. The schemes
it describes are quite curious, including photographic memories, selectrons, and various
other schemes. Also drum memories, including the rather mythical notion of a drum
spinning at 60,000 rpm.
paul
On 4/12/24 10:28, Chuck Guzis via cctalk wrote:
The problem with a lot of these old machines was they relied on a lot of
electro-mechanical devices that would today be replaced by electronics and a few simple
actuators. These mechanical devices need to be adjusted and maintained and have lots of
parts to wear out. While I only started with IBM in 1979 I still got to work on machines
that would now be considered electro-mechanical nightmares. Isn't that the IBM 2321 Data Cell drive?
Same idea, but I recall the cabinets being lower to the floor and the media being more
rigid than the 2321 noodles. Then again, it's been the better part of 50 years, and
it could well have been a 2321.
Memory rot sucks.
Having one's files "photostored" at
LLL was a chancy proposition. There
were bootleg programs to access every file for a user, just to keep them
from being consigned to the photostore.
It was chancy at LBL as well. The mechanical handling of the 1360 photostore cells was
something that would have defied the imagination of Rube Goldberg, and chips routinely
ended up in places where they didn't belong (although they did make pretty cool
bookmarks for my teenage self).