how fast were drum memories?

Paul Koning paulkoning at
Thu May 10 11:29:32 CDT 2018

> On May 10, 2018, at 10:37 AM, Grif <grif615 at> wrote:
> I wonder how the late generation paging disks (fixed head per track) like DG used in the 80's compared?

One that comes to mind is the DEC RS04.  It spins at roughly 3600 rpm (a hair less, so obviously a 2 pole induction motor running off 3-phase 60 Hz power).  Transfer rate is 0.5 megabytes per second, but still, at that RPM, average latency is 8.5 ms.


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