30 Dec
2016
30 Dec
'16
12:14 p.m.
On 12/30/2016 09:49 AM, Paul Koning wrote:
I have an old set of lecture notes I'm
translating, for a course on
computer design from 1948, which discusses various memory types. Not
core memory, that came later. But it mentions drums, and theorizes
that those might be operated at 60,000 rpm... I'm not sure where
that optimism came from. Perhaps because the author was a
mathematician rather than a mechanical engineer?
CDC ADL back in the late 1960s was testing a prototype high-speed drum
for the STAR--100K RPM in vacuo, ISTR. Probably a Jim
Thornton-inspired scheme. I do recall Neil Lincoln mentioning that the
observation window became coated with drum material in the first few
minutes.
The idea was a very fast paging store. That and the SCROLL tape/disk
device are two that come to mind.
Anent the LGP30--some drums were equipped with several heads spaced
around the same track to cut down on latency.
Logic need not be vacuum-tube or transistor--I recall the Univac Solid
State machines that used magnetic core as well as the Parametrons of NEC.
Drum machines persisted a bit longer than one would expect; e.g., the
Litton 1601 was produced in the early 70s.
A photo:
http://techno-science.ca/en/collection-research/collection-item.php?id=1982…
Technical reference manual:
http://bitsavers.informatik.uni-stuttgart.de/pdf/litton/Litton1600_Technica…
Bit serial architecture, of course. An odd bird, if there ever was one.
--Chuck