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 ...

[Ken Shirriff] is making those good ol’ days come alive with a series of articles relating to his work with hardware at the Computer History ... of the IBM 1401’s qui-binary arithmetic.

Production ended in 1961 as the RAMAC computer became obsolete the following year upon the arrival of IBM's 1405 Disk Storage Unit for the IBM 1401. By 1981, Apple introduced its first hard drive ...