IBM 2301 Drum Storage


The IBM 2301 fixed-head disk, or "drum". Drums were often used as main memory in the 1940s and 50s. By the 1960s they were used mainly for swapping and paging. The access time was significantly faster than a moving-head disk, but the capacity much smaller.

Illustration: Introduction to IBM Data Processing Systems, IBM Textbook C20-1684, 1968.

Frank da Cruz / / Columbia University Computing History / Feb 2001