On 1/3/22 1:23 PM, Paul Koning wrote: > The 6603 is highly unusual because it has 12 bit parallel data flow, rather > than bit-serial as everyone else did (until Cray went back to parallel with > the Cray 1, if I remember right). That made the 6603 very much faster, as > far as data throughput goes, than any other drive for quite a number of > years. It also has variable sector counts depending on cylinder number, > which came back a long time later. And it has a rotating head actuator > rather than linear motion, just as recent hard drives do.
The 808/6638 is parallel also (I even have one of the heads in my desk drawer memorabilia collection (6 channel). A real Rube Goldberg setup--4 spindles, 2 motors, 2 positioners, with each positioner having only 32 possible positions. 12 heads per "track" on 32 surfaces gives you 384 track access without moving. There's a photo on twitter: https://twitter.com/DonaldM38768041/status/1215804561333473280/photo/2 showing a guy standing before an open one at Fermilab. --Chuck
