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 CPU microprocessors appeared, beginning with the Intel 4004 in 1971, the term "minicomputer" came to mean a machine that lies in the middle range of the computing spectrum, in between the smallest mainframe computers and the microcomputers. The term "minicomputer" is seldom used today; the contemporary term for this class of system is "midrange computer", such as the higher-end SPARC from Oracle, Power ISA from IBM, and Itanium-based systems from Hewlett-Packard.
History
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Definition
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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 process control or accounting. On these machines, programming was generally carried out in their custom machine language, or even hard-coded into a plugboard, although some used a form of BASIC.[citation needed][example needed] DEC wrote, regarding their PDP-5, that it was "the world’s first commercially produced minicomputer".[10] It meets most definitions of "mini" in terms of power and size, but was designed and built to be used as an instrumentation system in labs, not as a general-purpose computer.[11] Many similar examples of small special-purpose machines exist from the early 1960s, including the UK Ferranti Argus and Soviet UM-1NKh.
The CDC 160, circa 1960, is sometimes pointed to as an early example of a minicomputer, as it was small, transistorized and (relatively) inexpensive. However, its basic price of $100,000 (equivalent to $1,029,921 in 2023) and custom desk-like chassis places it within the "small system" or "midrange computer"[12] category as opposed to the more modern use of the term minicomputer. Nevertheless, it retains a strong contender for the term "first minicomputer".[11]
1960s and 1970s success
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Most computing histories point to the 1964 introduction of Digital Equipment Corporation's (DEC) 12-bit PDP-8 as the first minicomputer.[13] Some of this is no doubt due to DEC's widespread use of the term starting in the mid-1960s.[14] Smaller systems, including those from DEC like the PDP-5 and LINC,[15] had existed prior to this point, but it was the PDP-8 combination of small size, general purpose orientation and low price that puts it firmly within the modern definition. Its introductory price of $18,500[16] (equivalent to $178,866 in 2023) places it in an entirely different market segment than earlier examples like the CDC 160.
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.
Raytheon RDS 500 seismic processing system in Benghazi in 1978 Varian Data Machines system connected to analogue tape playback system in 1984Early 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.
Raytheon RDS 704 onsite seismic processing system in Mogadishu in 1974As 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 seismic exploration for oil and gas in the early 1970s saw the widespread use of minicomputers in dedicated processing centres close to the data collection crews. Raytheon Data Systems RDS 704 and later RDS 500 were predominantly the systems of choice for nearly all the geophysical exploration as well as oil companies.[18]
At the launch of the MITS Altair 8800 in 1975, Radio Electronics magazine referred to the system as a "minicomputer", although the term microcomputer soon became usual for personal computers based on single-chip microprocessors. At the time, microcomputers were 8-bit single-user, relatively simple machines running simple program-launcher operating systems like CP/M or MS-DOS, while minis were much more powerful systems that ran full multi-user, multitasking operating systems, such as VMS and Unix.
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 VAX, which they referred to as a superminicomputer, or supermini, that caused the mini market to move en-masse to 32-bit architectures. This provided ample headroom even as single-chip 16-bit microprocessors like the TMS 9900 and Zilog Z8000 appeared in the later 1970s. Most mini vendors introduced their own single-chip processors based on their own architecture and used these mostly in low-cost offerings while concentrating on their 32-bit systems. Examples include the Intersil 6100 single-chip PDP-8, DEC T-11 PDP-11, microNOVA and Fairchild 9440 Nova, and TMS9900 TI-990.
Mid-1980s and 1990s decline
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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 Motorola 68000 offered a significant percentage of the performance of a typical mini in a desktop platform. True 32-bit processors like the National Semiconductor NS32016, Motorola 68020 and Intel 80386 soon followed. By the mid-1980s, high-end microcomputers offered compute performance equal to low-end and mid-range minis, and the new RISC approach promised performance levels well beyond the fastest minis, and even high-end mainframes.
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 hard drives rapidly pushed past the 100 MB range by 1990, and the introduction of inexpensive and easily deployable local area network (LAN) systems provide solutions for those looking for multi-user systems. The introduction of the workstation machines opened new markets for graphics-based systems that the terminal-oriented minis could not even address. Minis retained a force for those using existing software products or those who required high-performance multitasking, but the introduction of newer operating systems based on Unix began to become highly practical replacements for these roles as well.
Mini vendors began to rapidly disappear through this period. Data General responded to the changing market by focusing entirely on the high-performance file server market, embracing a role within large LANs that appeared resilient. This did not last; Novell NetWare rapidly pushed such solutions into niche roles, and later versions of Microsoft Windows did the same to Novell. DEC decided to move into the large-computer space instead, introducing the VAX 9000 mainframe in 1989, but it was a flop in the market and disappeared after almost no sales. The company then attempted to enter the workstation and server markets with the DEC Alpha, but was too late to save the company and they eventually sold their remains to Compaq in 1998. By the end of the decade all of the classic vendors were gone; Data General, Prime, Computervision, Honeywell, and Wang, failed, merged, or were bought out.
Today, only a few proprietary minicomputer architectures survive. The IBM System/38 operating system, which introduced many advanced concepts, lives on with IBM's AS/400. Great efforts were made by IBM to enable programs originally written for the IBM System/34 and System/36 to be moved to the AS/400. After being rebranded multiple times, the AS/400 platform was replaced by IBM Power Systems running IBM i. In contrast, competing proprietary computing architectures from the early 1980s, such as DEC's VAX, Wang VS, and Hewlett-Packard's HP 3000 have long been discontinued without a compatible upgrade path. OpenVMS runs on HP Alpha and Intel IA-64 (Itanium) CPU architectures.
Tandem Computers, which specialized in reliable large-scale computing, was acquired by Compaq in 1997, and in 2001 the combined entity merged with Hewlett-Packard.[22] The NonStop Kernel-based NonStop product line was re-ported from MIPS processors to Itanium-based processors branded as 'HP Integrity NonStop Servers'. As in the earlier migration from stack machines to MIPS microprocessors, all customer software was carried forward without source changes. Integrity NonStop continues to be HP's answer for the extreme scaling needs of its very largest customers. The NSK operating system, now termed NonStop OS, continues as the base software environment for the NonStop Servers, and has been extended to include support for Java and integration with popular development tools like Visual Studio and Eclipse. Later, Hewlett-Packard would split into HP and Hewlett-Packard Enterprise. The NonStop products and the DEC products would then be sold by HPE.
Industrial impact and heritage
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A variety of companies emerged that built turnkey systems around minicomputers with specialized software and, in many cases, custom peripherals that addressed specialized problems such as computer-aided design, computer-aided manufacturing, process control, manufacturing resource planning, and so on. Many if not most minicomputers were sold through these original equipment manufacturers and value-added resellers.
Several pioneering computer companies first built minicomputers, such as DEC, Data General, and Hewlett-Packard (HP) (who now refers to its HP3000 minicomputers as "servers" rather than "minicomputers"). And although today's PCs and servers are clearly microcomputers physically, architecturally their CPUs and operating systems have developed largely by integrating features from minicomputers.[citation needed]
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
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See also
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Notes
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For comparison, the CDC 160 sold about 50 units.
References
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Not to be confused with Laptop , a microcomputer of a certain form factor, designed for consumer use.
A military-type mobile computer housed in a reinforced case A portable computer with three LCD screens A portable computer with one 20.1-inch LCD screen, EATX motherboard The MIT Suitcase Computer, MIT Digital Systems Laboratory, 1975A portable computer is a computer designed to be easily moved[1] from one place to another, as opposed to those designed to remain stationary at a single location such as desktops and workstations. These computers usually include a display and keyboard that are directly connected to the main case, all sharing a single power plug together, much like later desktop computers called all-in-ones (AIO) that integrate the system's internal components into the same case as the display.[2] In modern usage, a portable computer usually refers to a very light and compact personal computer such as a laptop, miniature or pocket-sized computer, while touchscreen-based handheld ("palmtop") devices such as tablet, phablet and smartphone are called mobile devices instead.
The first commercially sold portable computer might be the 20-pound (9.1 kg) MCM/70, released 1974. The next major portables were the 50-pound (23 kg) IBM 5100 (1975), Osborne's 24-pound (11 kg) CP/M-based Osborne 1 (1981) and Compaq's 28-pound (13 kg), advertised as 100% IBM PC compatible Compaq Portable (1983). These luggable computers still required a continuous connection to an external power source;[3] this limitation was later overcome by the laptop computers.[4][3] Laptops were followed by lighter models such as netbooks, so that in the 2000s mobile devices and by 2007 smartphones made the term "portable" rather meaningless. The 2010s introduced wearable computers such as smartwatches.[5]
Portable computers, by their nature, are generally microcomputers.[6] Larger portable computers were commonly known as 'Lunchbox' or 'Luggable' computers. They are also called 'Portable Workstations' or 'Portable PCs'. In Japan they were often called 'Bentocom'. (ベントコン, Bentokon) from "bento".[citation needed]
Portable computers, more narrowly defined, are distinct from desktop replacement computers in that they usually were constructed from full-specification desktop components, and often do not incorporate features associated with laptops or mobile devices. A portable computer in this usage, versus a laptop or other mobile computing device, have a standard motherboard or backplane providing plug-in slots for add-in cards. This allows mission specific cards such as test, A/D, or communication protocol (IEEE-488, 1553) to be installed. Portable computers also provide for more disk storage by using standard disk drives and provide for multiple drives.
Early history
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SCAMP
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In 1973, the IBM Los Gatos Scientific Center developed a portable computer prototype called SCAMP (Special Computer APL Machine Portable) based on the IBM PALM processor with a Philips compact cassette drive, small CRT and full function keyboard. SCAMP emulated an IBM 1130 minicomputer in order to run APL\1130.[7] In 1973, APL was generally available only on mainframe computers, and most desktop sized microcomputers such as the Wang 2200 or HP 9800 offered only BASIC. Because SCAMP was the first to emulate APL\1130 performance on a portable, single user computer, PC Magazine in 1983 designated SCAMP a "revolutionary concept" and "the world's first personal computer".[8][9] The engineering prototype is in the Smithsonian Institution.[10]
Xerox NoteTaker
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Xerox NoteTaker, developed in 1976 at Xerox PARC, was a precursor to later portable computers from Osborne Computer Corporation and Compaq, though it remained a prototype and did not enter production.
IBM 5100
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IBM 5100 (1975)Successful demonstrations of the 1973 SCAMP prototype led to the first commercial IBM 5100 portable microcomputer launched in 1975. The product incorporated an IBM PALM processor, 5-inch (130 mm) CRT, full function keyboard and the ability to be programmed in both APL and BASIC for engineers, analysts, statisticians and other business problem-solvers. (IBM provided different models of the 5100 supporting only BASIC, only APL, or both selectable by a physical switch on the front panel.)[11][12] IBM referred to its PALM processor as a microprocessor, though they used that term to mean a processor that executes microcode to implement a higher-level instruction set, rather than its conventional definition of a complete processor on a single silicon integrated circuit; the PALM processor was a large circuit board populated with over a dozen chips. In the late 1960s, such a machine would have been nearly as large as two desks and would have weighed about half a ton (0.45 t). In comparison, the IBM 5100 weighed about 53 pounds (24 kg and very portable for that time).[13]
MIT Suitcase Computer
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The MIT Suitcase Computer, constructed in 1975, was the first known microprocessor-based portable computer. It was based on the Motorola 6800. Constructed in a Samsonite suitcase approximately 20 by 30 by 8 inches (510 mm × 760 mm × 200 mm) and weighing approximately 20 lb (9.1 kg), it had 4K of SRAM, a serial port to accept downloaded software and connect to a modem, a keyboard and a 40-column thermal printer taken from a cash register. Built by student David Emberson in the MIT Digital Systems Laboratory as a thesis project, it never entered production. It is currently in the collection of Dr. Hoo-Min D. Toong.[citation needed]
Micro Star or Small One
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An early portable computer was manufactured in 1979 by GM Research,[14] a small company in Santa Monica, California. The machine which was designed and patented by James Murez. It was called the Micro Star and later the name was changed to The Small One. Although Xerox claims to have designed the first such system, the machine by Murez predated anything on the market or that had been documented in any publication at the time – hence the patent was issued. As early as 1979, the U.S. Government was contracting to purchase these machines. Other major customers included Sandia Labs, General Dynamics, BBN (featured on the cover of their annual report in 1980 as the C.A.T. system) and several dozen private individuals and companies around the world. In 1979, Adam Osborne viewed the machine along with several hundred other visitors at the first computer show that was sponsored by the IEEE Westec in Los Angeles. Later that year the machine was also shown at the first COMDEX show.
Portal R2E CCMC
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R2E CCMC Portal laptop in September 1980 at the SICOB show in PARISThe portable micro computer; the "Portal" of the French company R2E Micral CCMC officially appeared in September 1980 at the Sicob show in Paris. The Portal was a portable microcomputer designed and marketed by the studies and developments department of the French firm R2E Micral in 1980 at the request of the company CCMC specializing in payroll and accounting. The Portal was based on an intel 8085 processor, 8-bit, clocked at 2 MHz. It was equipped with a central 64 KB RAM, a keyboard with 58 alpha numeric keys and 11 numeric keys (separate blocks), a 32-character screen, a floppy disk: capacity = 140 000 characters, of a thermal printer: speed = 28 characters / sec, an asynchronous channel, a synchronous channel, a 220 V power supply. Designed for an operating temperature of 15–35 °C (59–95 °F), it weighed 12 kilograms (26 lb) and its dimensions were 45 cm × 45 cm × 15 cm (17.7 in × 17.7 in × 5.9 in). It provided total mobility. Its operating system was Prolog. A few hundred were sold between 1980 and 1983.
Osborne 1
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Osborne 1 (1981)The first mass-produced microprocessor-based portable computer released in 1981 was the Osborne 1, developed by Osborne, which owed much to the NoteTaker's design. The company had early success with the design and went public but later due to small screen sizes and other devices being released found trouble selling the Osborne.[15] The Osborne 1 is about the size and weight of a sewing machine, and was advertised as the only computer that would fit underneath an airline seat.[16]
Kaypro
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Another early portable computer released in 1982 was named the Kaypro II, although it was the company's first commercially available product. Some of the press mocked its design—one magazine described Kaypro Corporation as "producing computers packaged in tin cans".[17] Others raved about its value, as the company advertised the Kaypro II as "the $1,595 computer that sells for $1,595",[18] some noting that the included software bundle had a retail value over $1,000 by itself, and by mid-1983 the company was selling more than 10,000 units a month, briefly making it the fifth-largest computer maker in the world. It managed to correct most of the Osborne 1's deficiencies: the screen was larger and showed more characters at once, the floppy drives stored over twice as much data, the case was more attractive-looking, and it was also much better-built and more reliable.
Grid Compass
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Macintosh Portable (1989) Grid Compass (1982)The Grid Compass ran its own operating system, GRiD-OS. Its specialized software and high price (US$8,000–10,000) meant that it was limited to specialized applications. The main buyer was the U.S. government. NASA used it on the Space Shuttle during the early 1980s, as it was powerful, lightweight, and compact. The military Special Forces also purchased the machine, as it could be used by paratroopers in combat.[19]
Post-IBM PC portables
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Compaq Portable and competitors
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Although Columbia Data Product's MPC 1600, "Multi Personal Computer" came out in June 1983,[20][21] one of the first extensively IBM PC compatible computers was the Compaq Portable. Eagle Computer then came out with their offering.[22] and Corona Data Systems's PPC-400.,[23] the "portable" Hyperion Computer System.[24] Both Eagle Computer and Columbia were sued by IBM for copyright infringement of its BIOS. They settled and were forced to halt production. Neither the Columbia nor the Eagle were nearly as IBM PC DOS compatible as Compaq's offerings.
Commodore SX-64
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The first full-color portable computer was the Commodore SX-64 in January 1984..
Atari STacy
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Originally announced in 1987, the Atari STacy was released to the public in December 1989 and was one of the first laptop-like portables.[25][26]
Apple Macintosh Portable
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Apple Inc. introduced and released the Macintosh Portable in 1989, though this device came with a battery, which added to its substantial weight. The Portable has features similar to the Atari STacy, include integrated trackball and clamshell case.
IBM PS/2 Portable
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After release of IBM PC Convertible in 1986, IBM still produced classic portable computers, include released in 1989 PS/2 P70 (with upgrade in 1990 to P75), and IBM produce portables for up to release of PS/2 Note and PS/55note notebook lines.
Modern portables
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In today's world of laptops, smart phones, and tablets, portable computers have evolved and are now mostly used for industrial, commercial or military applications.[27][28][29][30]
Timeline
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See also
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References
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