Digital Development Corporation Drum Memory Disk
1960s
Model 9762, Serial #126240

The Digital Development Corporation Mass Storage Module Drive was used in the Control Data Corporation CDC-636 computer and represents an alternative memory technology that was crushed by the emergence of core memory technology.

This unit was manufactured on October 20, 1966 in La Jolla
California. The drum rotates a 3,600 RPM, with a data transfer rate of 60 CPS. Once the unit reached its operational temperature, it had to cool down for three hours before the cover could be opened for servicing.

It contains 1,024 individual read and write heads between .002 and .0018 inches from the drum surface.

Donor: Louis Benton, Staff