Definition: RAMAC

(Random Access Method of Accounting and Control) The first hard disk computer, introduced by IBM in 1956. All 50 of its 24" platters combined held less than five million alphanumeric characters. Weighing more than a ton, RAMAC was half computer, half tabulator, and more than a thousand units were built until production ceased in 1961. The RAMAC had a drum memory for program storage, but its I/O was wired by plugboard. The machine was a major breakthrough as all prior computer storage used sequential magnetic tape.

The RAMAC sold for approximately $35,000 in the late 1950s, equivalent to roughly $300,000 in today's dollars. Much of the cost was RAMAC's "huge" disk system. See tabulator.

The RAMAC - One MP3 File

Although this was amazing technology in 1956, RAMAC's 50 platters in total held the equivalent of "one" MP3 music file. (Images courtesy of IBM.)

RAMAC Name Resurrected

In 1994, IBM named its hard disk array RAMAC. In 38 years, areal density on the disk platters vaulted from 2,000 to 260,000,000 bits per square inch. Access time decreased from 600 milliseconds to 9.5. (Image courtesy of IBM.)

Would They Have Believed It?

This is a hard drive sale at a Micro Center store in 2022 for 800,000 times as much storage as the RAMAC. (Image courtesy of Micro Center.)