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.