23 Sep
2022
23 Sep
'22
9:33 p.m.
On 9/23/22 11:41, Paul Koning wrote:
Another way to get high speed: one of CDC's first
disk drives, the 6603, wrote several bits in parallel. 4 bits? 12? I don't
remember, but it made for a throughput spec that was unbeaten for nearly a decade.
I think the 6638 was the controller you may be thinking of; the drive
was the 808 (and 821 if you're after arcana). The 6603 was the old
Bryant 4000 disk. I've got a head from one (808)--6 channels quite
visible. Each head assembly had several heads. 4 spindles with 2
actuators (hydraulic), one on top and the other on the bottom, with the
actuator sitting between the spindles, so accessed in a sort of
pushme-pullyu arrangemt. Transfers, of course, were 12 bits wide.
The 821, which I never saw outside of Special Systems Divison, increased
the capacity. It was notoriously unreliable with a tendency to go "not
ready" without notice. Otherwise, it was the tall gray cabinet that
looked exactly like an 808.
--Chuck