Minicomputer

A minicomputer, or colloquially mini, is a type of general-purpose computer mostly developed from the mid-1960s^[1][2], built significantly smaller and sold at a much lower price than mainframe^[3] and mid-size computers from IBM and its direct competitors. By 21st century-standards however, a mini is an exceptionally large machine. Minicomputers in the traditional technical sense covered here are only small relative to generally even earlier and much bigger machines.

The class formed a distinct group with its own software architectures and operating systems. Minis were designed for control, instrumentation, human interaction, and communication switching, as distinct from calculation and record keeping. Many were sold indirectly to original equipment manufacturers (OEMs) for final end-use application. During the two-decade lifetime of the minicomputer class (1965–1985), almost 100 minicomputer vendor companies formed. Only a half-dozen remained by the mid-1980s.^[4]

When single-chip CPU microprocessors appeared in the 1970s, the definition of "minicomputer" subtly shifted: the word came to mean a machine in the middle range of the computing spectrum, between mainframe computers and microcomputers. The easily misunderstood term "minicomputer" is less often applied to later like systems; a near-synonymous (IBM-adjacent) expert term for this class of system is "midrange computer". Non-experts however have begun to apply the "minicomputer" label to credit card-sized single-board computers (q.v.).