On Fri, 2024-04-12 at 15:04 -0400, Paul Koning 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.
From 1968 until almost 2000, Caltech Jet Propulsion Laboratory had
Univac mainframes, first 1108 (three of them), then 1110, then 1100/40,
then 1100/80, then 2200.
We would run 50 time-shariing jobs and ten batch jobs on a 262k
machine. Swap was on eleven 4 millisecond FH432 (FH="Flying Head")
drums, able to hold one core load each, plus several 7 millisecond
FH1782 drums with four core loads each. Users' files were on FASTRAND
II™ -- an 5,000 pound drum machine the size of two upright pianos,
holding about 22 megawords. With 92 millisecond access time, calling it
FASTRAND was obviously a marketing fiction. A bunch of Calcomp disk
drives eventually replaced the Fastrand.
https://en.wikipedia.org/wiki/UNIVAC_FASTRAND
The 1100 series began with the ERA 1101, built for the Navy's "project
13," or 1101 in binary.