ABSTRACT
The magnetic disk technology was developed in the 1950s to provide a higher capacity than magnetic drums, which with one head per track constituted a fixed head system, while disks introduced a movable head system. The movable heads were shared by all tracks, resulting in a significant cost reduction. IBM’s RAMAC — Random Access Method for Accounting and Control [Matick 1977] — announced in 1956 was the first magnetic disk storage system with a capacity of 5 Megabytes (MB) and a $10,000 price tag.
