VAX 780 on eBay

Chuck Guzis cclist at sydex.com
Mon Jan 3 17:01:17 CST 2022


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


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