The class called minicomputers emerged in the 1960s and machines were generally known at the time as minicomputers – especially models from Digital Equipment Corporation (PDP line), Data General, Hewlett-Packard (HP3000 line and successors), and Sun Microsystems (SPARC Enterprise). These were widely used in science and research as well as for business.
IBM favored the term "midrange computer" for their comparable, but more business-oriented, systems.
IBM Midrange Systems included
Although the systems numbered appear to simply be a series of successions, they weren't. Unlike the System/3, which was multi-user, the System/32 was not.
- System/3 was the first of the IBM midrange systems (1969)
- System/32 (introduced in 1975)  was a 16-bit single-user system also known as the IBM 5320.
- System/34 was intended as successor to both the 3 and the 32.
- System/36 (1983) had two 16-bit processors with an operating system that supported multiprogramming.
- System/38 (1979) was the first Midrange system to have an integrated relational database management system (DBMS). The 38 had 48-bit addressing.
- AS/400 was introduced under that name in 1988, renamed eServer iSeries in 2000, and subsequently became IBM System i in 2006.
- IBM System i was subsequently replaced by the IBM Power Systems in April 2008.
Since the 1990s, when the client–server model of computing became predominant, computers of the comparable class are instead usually known as servers to recognize that they usually "serve" end users at their "client" computers.
Midrange systems are primarily high-end network servers and other types of servers that can handle the large-scale processing of many business applications[dubious ]. Although not as powerful as mainframe computers[dubious ][clarification needed], they are less costly to buy, operate, and maintain than mainframe systems and thus meet the computing needs of many organizations. Midrange systems have become popular as powerful network servers to help manage large Internet Web sites, corporate intranets and extranets, and other networks. Today, midrange systems include servers used in industrial process-control and manufacturing plants and play major roles in computer-aided manufacturing (CAM). They can also take the form of powerful technical workstations for computer-aided design (CAD) and other computation and graphics-intensive applications. Midrange system are also used as front-end servers to assist mainframe computers in telecommunications processing and network management.
- Estabrooks, Maurice (1995). Electronic technology, corporate strategy, and world transformation. Westport, Conn.: Quorum Books. p. 53. ISBN 0899309690.
- Bell, Gordon (9 January 2015). "Rise and Fall of Minicomputers". Engineering and Technology History Wiki. Retrieved 28 January 2017.
- "1969 IBM System/3 promotional ad - midrange, minicomputer, Computer History, RPG". Computer History Archives Project. Netherlands.
- "IBM System/3 announcement" (PDF).
- "IBM System/32". IBM Corporation.
- "now referred to as small or midsize servers." "Minicomputer". Britannica.com.
- "PC Magazine, Definition of: midrange computer".