IBM and the birth of the hard drive

On September 13, 1956, a small team of IBM engineers in San Jose introduced the first computer disk storage system. The 305 RAMAC (Random Access Method of Accounting and Control) could store five million characters (five megabytes) of data on 50 disks, each 24 inches in diameter. RAMAC's revolutionary recording head could go directly to any location on a disk surface without reading all the information in between. This IBM innovation made it possible to use computers for airline reservations, automated banking, medical diagnosis and space flights. Other IBM innovations during this period included:

"Write wide, read narrow" (1957), which made it possible to read data accurately even if tape heads were out of alignment.


Multiple density support (1957), which allowed users to read tape written on older machines, preserving the investment which IBM customers had made in the previous generation of magnetic storage.

Say hello to
your hard drive

Visualize MR and
GMR Heads in

Observe the
physics of GMR
in motion

[GMR Lead Story | IBM Research home page]

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