3 Jan
2022
3 Jan
'22
3:01 p.m.
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