IBM introduced the 305 RAMAC (Random Access Method of Accounting and Control) in 1956. It was the first computer to use a magnetic hard disk drive for storage.
The first hard drives had 100 concentric tracks per side. Each track stored 500 alphanumeric characters, giving 1950s hard drives a storage capacity of up to 5 million characters -- about the same amount of text contained in 10 novels. The hard drive enabled users to retrieve information directly and in a fraction of a second.
Hard drives eventually became commodities by the late 1990s, and the division started losing money for IBM. The company sold its hard disk drive business to Hitachi for $2 billion in 2002. By then, the drives were a whole lot smaller than the '50s ancestor pictured here.
