how fast were drum memories?

[Al Kossow]

On 5/10/18 9:29 AM, Paul Koning via cctalk wrote:

> 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).
Vermont Research drums (model 1175B) spun at 3450 rpm 3ph 220v, The HP 2773 on the 2000A TSB was from VR so I expect RPM
would be similar for most drums of similar diameter.

from https://ia800809.us.archive.org/27/items/TNM_Drum_memories_-_Vermont_Research_Corp_1966_20170826_0105