Sad thing is, I wouldn't know a drum memory if it
fell on me. :^)
I imagine they were made by the 'heavies': CDC, GE, IBM, Burroughs,
etc.
There were a lot of little guys doing them for the heavies. Many of the
old desktop/deskside manicnes from the 60s had them. later in the 60s and
early 70s they were used with one head pertrack as swapping drums for
bigger machines.
I recall seeing some made by *Hughes* for sale in a
Meshna catalog,
several eons ago.
Yep, remember that. Check any old 76/77 byte and you may see adds for
them.
Allison