Definition: IBM 1401

IBM's second successful commercial computer (the first was the 650). Introduced in 1959 and offered until 1971, the 1401 was an outstanding success. More than 12,000 systems were installed, and it was estimated that by the mid-1960s, half of the world's computers were 1401s.

A fully equipped 1401 had 16KB of six-bit core memory and six tape drives. All input was on punch cards, and all output was printed or punched into blank cards. There was no display screen. In 1960, IBM introduced the larger 1410 with 80KB of memory, which also ran 1401 programs.

Taken down for maintenance many hours a month while IBM service technicians cleaned and tested its innards, the 1401 was extremely reliable for its time. In order to migrate to IBM's first family of computers, emulators were built into the System/360 series.

Stand-Alone or a Peripheral
The 1401 was used as a stand-alone computer but was also used in large enterprises as only an input/output peripheral to larger IBM computers. Equipped with card readers and card punch devices, the 1401 was often used in the datacenter to transfer cards to tape and later print the results from the tapes that were updated. For a personal story relating to the 1401, see software bloat. See IBM 701, IBM 650 and System/360.

IBM 1401

The 1401 was very successful. Its architecture and machine language were simple and straightforward. (Image courtesy of IBM.)