how fast were drum memories?

Chuck Guzis cclist at
Thu May 10 09:57:32 CDT 2018

On 05/10/2018 07:29 AM, Paul Koning via cctalk wrote:

> I'm wondering what the reality of fast drum memories looked like, and whether anyone came even close to these numbers.  Also, am I right in thinking they are at least in principle achievable?  I know I could run the stress numbers, but haven't done so.

All of the STAR-100 stations, including the paging station used drums.

Jim Thornton and folks at CDC ADL were working on a 100K RPM drum
spinning in vacuo for a paging store, but they couldn't get it to work
reliably.   At any rate, STAR was the last system I saw fast drums on
and you can check the figures in the Bitsavers documentation under
cdc/cyber/cyber200.  At any rate, a head-per-track drum could be much
faster than a disk.

There were big slow drums, also.  Consider the Univac FASTRAND unit.


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