Model 301 Magnetic Drum Unit

The Electrical Communication Laboratories (ECL) of Nippon Telegraph and Telephone Public Corporation (now NTT) needed to further improve performance of the DIPS-1 center unit, and as part of that effort, work started on the development of the Model 301 magnetic drum memory unit in 1971. This magnetic drum was designed for use as a high-speed auxiliary memory to fill the access gap between the main memory and magnetic disk memory units. The development goals were high density, high capacity, and higher speed, and it was decided to develop a compact, magnetic drum unit with low power consumption and outstanding economy.