Kenneth Olsen, a former researcher at the MIT Lincoln Laboratory, established the Digital Equipment Corporation (DEC) in August 1957. In August 1965, DEC announced the PDP-8, which used a 12-bit word length and cost $18,000. This small, inexpensive computer was suitable for a wide range of system applications and became the first minicomputer. The PDP-8 was held in very high regard and it underscored the existence of new markets in such fields as industrial controls, telecommunications controls, and scientific and engineering calculations that mainframes and other general-purpose computers could not support. As a result, Varian Data Machines, Data General (DG), Hewlett-Packard (HP), Interdata, and many other firms rushed to enter the minicomputer market. DEC updated its 12-bit PDP-8 series and in 1970 developed the 16-bit PDP-11 series. Ken Thompson and Dennis Ritchie working at Bell Labs developed the UNIX operating system in 1969, which was widely used on minicomputers．
Minicomputers from DEC and HP, DG's Nova series of minicomputers, and other minicomputers were imported into Japan. The Nova was one of the first commercial computers to use medium-scale integrated (MSI) circuitry. Japanese also began developing competing minicomputers, and Hitachi was first to market with the HITAC 10 in February 1969. The HITAC 10 was a 16-bit minicomputer with a 4K word memory and priced at ¥4.95 million. Hitachi's offering was followed by Fujitsu's FACOM R, NEC's NEAC M4, and Oki Electric's OKITAC-4300. Later in 1969, Matsushita Electric announced the MACC-7, which was followed by Toshiba's announcement of the TOSBAC-40 in 1970．
Entering the 1970s, independent software vendors in the United States started developing application software to enable minicomputers to be used for business applications. This movement gave birth to the small business computer (SBC) market. As minicomputer capabilities improved, multi-workstation systems, in which multiple terminals were controlled by a single minicomputer, were developed. In Japan, companies repurposed the miniature business computers, which had been developed in the early 1960s, into office computers. In this way, this sector followed a unique development path in Japan．
DEC announced the VAX-11/780 32-bit virtual memory super minicomputer in October 1977. “VAX” stood for the PDP-11's virtual address extension. DG announced the ECLIPSE in 1978. Japanese firms also started developing and releasing a succession of 32-bit super minicomputers in the late 1970s. Toshiba announced the TOSBAC 7/70 series in 1978, and in 1980 Hitachi announced the HITAC E-800, whose instructions were compatible with the HITAC M series. NEC rolled out the NEAC MS120, MS140, and MS190 in 1982. The MS190 achieved the world's fastest performance for scientific and engineering calculations by using current-mode logic LSI, borrowed from the company's largest mainframe, for its processing elements. In 1983, Fujitsu and Panafacom (today PFU) announced the FACOM S-3000 series and the PANAFACOM S-3000 series, the companies' first 32-bit super minicomputers. Mitsubishi Electric announced the MELCOM70 MX/3000 the following year．
NEC, in 1986, announced its MS4100 series, which featured a microprocessor architecture based on 32-bit CMOS VLSI processors. The following year, Fujitsu and Panafacom announced the A series (for ace), and Oki Electric announced the OKITAC8300. Mitsubishi Electric announced the MELCOM70 MX/5000 series of high-end 32-bit super minicomputers in the same year. In 1989, Mitsubishi Electric announced the MELCOM70 MX/5000-SP series of minicomputers that contained Japan's first automatic vectorizing FORTRAN compiler and a vector processor．
Around 1980, the minicomputer started losing its competitive edge over personal computers, as microprocessors became more powerful and more inexpensive. DEC fought the move to personal computers with the LSI-11 (1975), which implemented the PDP-11 in LSI, the LSI-11-2 (1977), and the LSI-11/23 (1979) as well as the Micro VAX-I (1984), which implemented the VAX-11 with gate arrays, the Micro VAX-II (1985), implemented in VLSI, and other machines. However, in 1989, DEC announced its DECStation series, which ran on general-purpose MIPS microprocessors, and in 1992 developed the Alpha processor — a RISC microprocessor with a next-generation 64-bit architecture — and loaded it on the company's workstations. Shortly after, however, the minicomputer category drew to a close. DEC and many other specialized minicomputer manufacturers had vanished by the end of the 1990s, as they were taken over by PC sales companies．