Minicomputer
A minicomputer, or colloquially mini, is a type of smaller general-purpose computer developed in the mid-1960s[1][2] and sold at a much lower price than mainframe[3] and mid-size computers from IBM and its direct competitors. In a 1970 survey, The New York Times suggested a consensus definition of a minicomputer as a machine costing less than US$25,000 (equivalent to $196,000 in 2023[4]), with an input-output device such as a teleprinter and at least four thousand words of memory, that is capable of running programs in a higher level language, such as Fortran or BASIC.[5]
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 companies formed and only a half dozen remained.[6]
When single-chip
History
Definition
The term "minicomputer" developed in the 1960s[7] to describe the smaller computers that became possible with the use of transistors and core memory technologies, minimal instructions sets and less expensive peripherals such as the ubiquitous Teletype Model 33 ASR.[6][8] They usually took up one or a few 19-inch rack cabinets, compared with the large mainframes that could fill a room.[9]
In terms of relative computing power compared to contemporary mainframes, small systems that were similar to minicomputers had been available from the 1950s. In particular, there was an entire class of drum machines, like the UNIVAC 1101 and LGP-30, that share some features of the minicomputer class. Similar models using magnetic delay-line memory followed in the early 1960s. These machines, however, were essentially designed as small mainframes, using a custom chassis and often supporting only peripherals from the same company. In contrast, the machines that became known as minicomputers were often designed to fit into a standard chassis and deliberately designed to use common devices like the ASR 33.
Another common difference was that most earlier small machines were not "general purpose", in that they were designed for a specific role like
The
1960s and 1970s success
Most computing histories point to the 1964 introduction of
In contemporary terms, the PDP-8 was a runaway success, ultimately selling 50,000 examples.[a] Follow-on versions using small scale integrated circuits further lowered the cost and size of the system. Its success led to widespread imitation, and the creation of an entire industry of minicomputer companies along Massachusetts Route 128, including Data General, Wang Laboratories and Prime Computer. Other popular minis from the era were the HP 2100, Honeywell 316 and TI-990.
Early minis had a variety of word sizes, with DEC's 12 and 18-bit systems being typical examples. The introduction and standardization of the 7-bit ASCII character set led to the move to 16-bit systems, with the late-1969 Data General Nova being a notable entry in this space. By the early 1970s, most minis were 16-bit, including DEC's PDP-11. For a time, "minicomputer" was almost synonymous with "16-bit", as the larger mainframe machines almost always used 32-bit or larger word sizes.
As integrated circuit design improved, especially with the introduction of the 7400-series integrated circuits, minicomputers became smaller, easier to manufacture, and as a result, less expensive. They were used in manufacturing process control, telephone switching and to control laboratory equipment. In the 1970s, they were the hardware that was used to launch the computer-aided design (CAD) industry[17] and other similar industries where a small dedicated system was needed.
The boom in worldwide
At the launch of the
The Tandem Computers NonStop product line shipped its first fully fault-tolerant cluster computer in 1976.[19][20][21]
Around the same time, minis began to move upward in size. Although several 24 and 32-bit minis had entered the market earlier, it was DEC's 1977
Mid-1980s and 1990s decline
By the early 1980s, the 16-bit market had all but disappeared as newer 32-bit microprocessors began to improve in performance. Those customers who required more performance than these offered had generally already moved to 32-bit systems by this time. But it was not long before this market also began to come under threat; the
All that really separated micros from the mini market was storage and memory capacity. Both of these began to be addressed through the later 1980s; 1 MB of RAM became typical by around 1987, desktop
Mini vendors began to rapidly disappear through this period.
Today, only a few proprietary minicomputer architectures survive. The
Industrial impact and heritage
A variety of companies emerged that built
Several pioneering computer companies first built minicomputers, such as
In the software context, the relatively simple OSs for early microcomputers were usually inspired by minicomputer OSs (such as CP/M's similarity to Digital's single user OS/8 and RT-11 and multi-user RSTS time-sharing system). Also, the multiuser OSs of today are often either inspired by, or directly descended from, minicomputer OSs.[citation needed] UNIX was originally a minicomputer OS, while the Windows NT kernel, the foundation for all current versions of Microsoft Windows, borrowed design ideas liberally from VMS. Many of the first generation of PC programmers were educated on minicomputer systems.[23][24]
Examples
- CII Mitra 15
- CDC 160A and CDC 1700
- DEC PDP and VAX series
- Data General Nova and Eclipse series
- Hewlett-Packard HP 3000 series and HP 2100 series
- Honeywell-Bull DPS 6/DPS 6000 series
- IBM midrange computers
- Interdata 7/32 and 8/32
- Norsk Data Nord-1, Nord-10, and Nord-100
- Ridge Computers Ridge 32 and Ridge 3200 series
- Texas Instruments TI-990
- CTL Modular One, from the UK
- K-202, first Polish minicomputer
See also
- The Soul of a New Machine – about the development of Data General's Eclipse/MV minicomputers in the early 1980s
- Charles Babbage Institute
- History of computing hardware (1960s–present)
- Superminicomputer
- Maxicomputer
Notes
- ^ For comparison, the CDC 160 sold about 50 units.
References
- ISBN 978-0226326832.
- ISBN 978-1133607298.
- ISBN 0899309690.
- ^ 1634–1699: McCusker, J. J. (1997). How Much Is That in Real Money? A Historical Price Index for Use as a Deflator of Money Values in the Economy of the United States: Addenda et Corrigenda (PDF). American Antiquarian Society. 1700–1799: McCusker, J. J. (1992). How Much Is That in Real Money? A Historical Price Index for Use as a Deflator of Money Values in the Economy of the United States (PDF). American Antiquarian Society. 1800–present: Federal Reserve Bank of Minneapolis. "Consumer Price Index (estimate) 1800–". Retrieved February 29, 2024.
- ^ Smith, William D. (April 5, 1970). "Maxi Computers Face Mini Conflict: Mini Trend Reaching Computers". The New York Times.
- ^ S2CID 21352766.
- ^ "Minicomputer". Britannica.com.
Minicomputer... the term was introduced in the mid-1960s.
- .
- ^ "Minicomputer". Britannica.com.
- ^ DIGITAL EQUIPMENT CORPORATION – Nineteen Fifty-Seven To The Present (PDF). Digital Equipment Corporation. 1975.
- ^ a b Lafferty, Stephen H. (January 2014). "Who Built The First Minicomputers?". Retrieved 24 January 2014.
- ^ "What Is the Difference Between a Microcomputer & a Minicomputer". Techwalla.
- ISBN 9780521766456.
- ZDNet. p. 4.
The term was coined by then DEC UK head John Leng, who sent a sales report saying, "Here is the latest minicomputer activity in the land of miniskirts as I drive around in my Mini Minor".
- ^ "The LINC: An Early "Personal Computer"". DrDobbs.com.
- ^ Jones, Douglas. "The Digital Equipment Corporation PDP-8 — Frequently Asked Questions".
- ^ "Computer-aided design".
- ISSN 0010-4841.
- ^ "Tandem History: An Introduction". Center Magazine: A Newsletter for Tandem Employees. 6 (1). Winter 1986.
- ^ "Tracing Tandem's History". NonStop News: A Newsletter for Tandem Employees. 9 (1). January 1986.
- ^ "History of TANDEM COMPUTERS, INC. – FundingUniverse". www.fundinguniverse.com. Retrieved 2023-03-01.
- ^ "Top-end server group comes home to HP". CNET. Retrieved 2023-02-28.
- ^ "History of Computers in Education".
- ISBN 978-1456751159.