【Hokushin Electric】 Magnetic Drum Unit for the Main Memory of Electronic Computers

Hokushin Electric (which later became Yokogawa Hokushin Electric, and today is known as Yokogawa Electric) developed a magnetic drum unit with low capacity (28K-286Kbit) and high-speed rotation (20,000-10,000rpm) for use as the main memory of electronic computers. This was used as the main memory unit for transistor computers such as NEC's NEAC-2201 and 2203, and Hitachi's HITAC-301. The MD 2A shown in the photo had a rotation speed of 10,000rpm, and a memory capacity of 64Kbit.

MD 2A Magnetic Drum Memory Unit