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96-451: The VAXserver was a family of minicomputers developed and manufactured by Digital Equipment Corporation (DEC) using processors implementing the VAX instruction set architecture (ISA). The VAXserver models were variants of various VAX-based computers which were configured to only run operating systems which were licensed for network server use and not interactive time-sharing use. This

192-426: A 19-inch rack . The backplanes allowed 25 modules in a single 5-1/4 inch section of rack, and allowed the high densities needed to build a computer. The original laboratory and system module lines were offered in 500 kilocycle, 5 megacycle and 10 megacycle versions. In all cases, the supply voltages were -15 and +10 volts, with logic levels of -3 volts (passive pull-down) and 0 volts (active pull-up). DEC used

288-610: A VAX CPU was the VAX-11/780 , announced in October 1977, which DEC referred to as a superminicomputer . Although it was not the first 32-bit minicomputer, the VAX-11/780's combination of features, price, and marketing almost immediately propelled it to a leadership position in the market after it was released in 1978. VAX systems were so successful that in 1983, DEC canceled its Jupiter project , which had been intended to build

384-586: 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

480-535: A new virtual memory system, and would also improve performance by processing twice as much data at a time. The system would, however, maintain compatibility with the PDP-11, by operating in a second mode that sent its 16-bit words into the 32-bit internals, while mapping the PDP-11's 16-bit memory space into the larger virtual 32-bit space. The result was the VAX architecture, where VAX stands for Virtual Address eXtension (from 16 to 32 bits). The first computer to use

576-476: A new device to be added easily, generally only requiring plugging a hardware interface board into the backplane and possibly adding a jumper to the wire wrapped backplane, and then installing software that read and wrote to the mapped memory to control it. The relative ease of interfacing spawned a huge market of third party add-ons for the PDP-11, which made the machine even more useful. The combination of architectural innovations proved superior to competitors and

672-467: A profit at the end of its first year. The original Laboratory Modules were soon supplemented with the "Digital System Module " line, which were identical internally but packaged differently. The Systems Modules were designed with all of the connections at the back of the module using 22-pin Amphenol connectors, and were attached to each other by plugging them into a backplane that could be mounted in

768-470: 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 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

864-438: A selection of System Building Blocks to implement a small 12-bit machine, and attached it to a variety of analog-to-digital (A to D) input/output (I/O) devices that made it easy to interface with various analog lab equipment. The LINC proved to attract intense interest in the scientific community, and has since been referred to as the first real minicomputer , a machine that was small and inexpensive enough to be dedicated to

960-485: A self-sustaining business, the company would be free to use them to develop a complete computer in their Phase II. The newly christened "Digital Equipment Corporation" received $ 70,000 from AR&D for a 70% share of the company, and began operations in a Civil War -era textile mill in Maynard, Massachusetts , where plenty of inexpensive manufacturing space was available. In early 1958, DEC shipped its first products,

1056-511: A separate input/output processor for further performance gains. Over 400 PDP-15's were ordered in the first eight months of production, and production eventually amounted to 790 examples in 12 basic models. However, by this time other machines in DEC's lineup could fill the same niche at even lower price points, and the PDP-15 would be the last of the 18-bit series. In 1962, Lincoln Laboratory used

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1152-485: A single large mainframe case, with a hexagonal control panel containing switches and lights mounted to lie at table-top height at one end of the mainframe. Above the control panel was the system's standard input/output solution, a punched tape reader and writer. Most systems were purchased with two peripherals , the Type 30 vector graphics display, and a Soroban Engineering modified IBM Model B Electric typewriter that

1248-659: A single task even in a small lab. Seeing the success of the LINC, in 1963 DEC took the basic logic design but stripped away the extensive A to D systems to produce the PDP-5 . The new machine, the first outside the PDP-1 mould, was introduced at WESTCON on August 11, 1963. A 1964 ad expressed the main advantage of the PDP-5, "Now you can own the PDP-5 computer for what a core memory alone used to cost: $ 27,000". 116 PDP-5s were produced until

1344-653: A successor to the PDP-10 mainframe, and instead focused on promoting the VAX as the single computer architecture for the company. Supporting the VAX's success was the VT52 , one of the most successful smart terminals . Building on earlier less successful models, the VT05 and VT50 , the VT52 was the first terminal that did everything one might want in a single inexpensive chassis. The VT52

1440-440: A turn to use the stripped-down TX-0, while largely ignoring a faster IBM machine that was also available. The two decided that the draw of interactive computing was so strong that they felt there was a market for a small machine dedicated to this role, essentially a commercialized TX-0. They could sell this to users where the graphical output or real-time operation would be more important than outright performance. Additionally, as

1536-677: Is most famous as the machine for which the Unix operating system was originally written. Unix ran only on DEC systems until the Interdata 8/32 . A more dramatic upgrade to the PDP-1 series was introduced in August 1966, the PDP-9 . The PDP-9 was instruction-compatible with the PDP-4 and −7, but ran about twice as fast as the −7 and was intended to be used in larger deployments. At only $ 19,900 in 1968,

1632-522: Is no reason for any individual to have a computer in his home." Unsurprisingly, DEC did not put much effort into the microcomputer area in the early days of the market. In 1977, the Heathkit H11 was announced; a PDP-11 in kit form. At the beginning of the 1980s, DEC built the VT180 (codenamed "Robin"), which was a VT100 terminal with an added Z80 -based microcomputer running CP/M , but this product

1728-448: 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 . The term "minicomputer" developed in the 1960s 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

1824-406: 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" category as opposed to the more modern use of the term minicomputer. Nevertheless, it retains a strong contender for

1920-567: The DEC Alpha product line began to make successful inroads in the mid-1990s, but was too late to save the company. DEC was acquired in June 1998 by Compaq in what was at that time the largest merger in the history of the computer industry. During the purchase, some parts of DEC were sold to other companies; the compiler business and the Hudson Fab were sold to Intel . At the time, Compaq

2016-539: The PDP line, with the PDP-8 and PDP-11 being among the most successful minis in history. Their success was only surpassed by another DEC product, the late-1970s VAX "supermini" systems that were designed to replace the PDP-11. Although a number of competitors had successfully competed with Digital through the 1970s, the VAX cemented the company's place as a leading vendor in the computer space. As microcomputers improved in

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2112-727: The SAGE system for the US Air Force , which used large screens and light guns to allow operators to interact with radar data stored in the computer. When the Air Force project wound down, the Lab turned their attention to an effort to build a version of the Whirlwind using transistors in place of vacuum tubes . In order to test their new circuitry, they first built a small 18-bit machine known as TX-0 , which first ran in 1956. When

2208-566: 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. For computational science , clusters of commodity PCs largely replaced minicomputers. Mini vendors began to rapidly disappear through this period. Data General responded to

2304-802: The "11" architecture was soon the industry leader, propelling DEC back to a strong market position. The design was later expanded to allow paged physical memory and memory protection features, useful for multitasking and time-sharing . Some models supported separate instruction and data spaces for an effective virtual address size of 128 KB within a physical address size of up to 4 MB. Smaller PDP-11s, implemented as single-chip CPUs, continued to be produced until 1996, by which time over 600,000 had been sold. The PDP-11 supported several operating systems, including Bell Labs ' new Unix operating system as well as DEC's DOS-11 , RSX-11 , IAS, RT-11 , DSM-11, and RSTS/E . Many early PDP-11 applications were developed using standalone paper-tape utilities. DOS-11

2400-543: The "Digital Laboratory Module" line. The Modules consisted of a number of individual electronic components and germanium transistors mounted to a circuit board , the actual circuits being based on those from the TX-2. The Laboratory Modules were packaged in an extruded aluminum housing, intended to sit on an engineer's workbench, although a rack-mount bay was sold that held nine laboratory modules. They were then connected together using banana plug patch cords inserted at

2496-439: The "sandbox" for a rising generation of engineers and computer scientists. Large numbers of PDP-11/70s were deployed in telecommunications and industrial control applications. AT&T Corporation became DEC's largest customer. RT-11 provided a practical real-time operating system in minimal memory, allowing the PDP-11 to continue DEC's critical role as a computer supplier for embedded systems . Historically, RT-11 also served as

2592-433: The 1950s, wiped out when new technical developments rendered their platforms obsolete, and even large companies like RCA and General Electric were failing to make a profit in the market. The only serious expression of interest came from Georges Doriot and his American Research and Development Corporation (AR&D). Worried that a new computer company would find it difficult to arrange further financing, Doriot suggested

2688-417: The 1960s to the 1990s. The company was co-founded by Ken Olsen and Harlan Anderson in 1957. Olsen was president until he was forced to resign in 1992, after the company had gone into precipitous decline. The company produced many different product lines over its history. It is best known for the work in the minicomputer market starting in the early 1960s. The company produced a series of machines known as

2784-572: The 1980s, culminating in the NVAX microprocessor implementation and VAX 7000/10000 series in the early 1990s. When a DEC research group demonstrated two prototype microcomputers in 1974—before the debut of the MITS Altair —Olsen chose to not proceed with the project. The company similarly rejected another personal computer proposal in 1977. At the time these systems were of limited utility, and Olsen famously derided them in 1977, stating "There

2880-466: 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 . DEC wrote, regarding their PDP-5, that it

2976-450: The CPU which allowed one to easily see the logic modules plugged into the wire-wrapped backplane of the CPU. Sold standard with 4 kWords of 12-bit core memory and a Teletype Model 33 ASR for basic input/output, the machine listed for only $ 18,000. The PDP-8 is referred to as the first real minicomputer because of its sub-$ 25,000 price. Sales were, unsurprisingly, very strong, and helped by

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3072-517: The PC, but was more expensive than, and completely incompatible with IBM PC hardware and software, offering far fewer options for customizing a system. Unlike CP/M and DOS microcomputers, every copy of every program for the Professional had to be provided with a unique key for the particular machine and CPU for which it was bought. At that time this was mainstream policy, because most computer software

3168-630: The PDP-8, all in software. Although not a huge seller, 142 LINC-8s were sold starting at $ 38,500. Like the original LINC to PDP-5 evolution, the LINC-8 was then modified into the single-processor PDP-12 , adding another 1000 machines to the 12-bit family. Newer circuitry designs led to the PDP-8/I and PDP-8/L in 1968. In 1975, one year after an agreement between DEC and Intersil , the Intersil 6100 chip

3264-459: The PDP-9 was a big seller, eventually selling 445 machines, more than all of the earlier models combined. Even while the PDP-9 was being introduced, its replacement was being designed, and was introduced as 1969's PDP-15 , which re-implemented the PDP-9 using integrated circuits in place of modules. Much faster than the PDP-9 even in basic form, the PDP-15 also included a floating point unit and

3360-700: The Professional was a superior machine, running inferior software. In addition, a new user would have to learn an awkward, slow, and inflexible menu-based user interface which appeared to be radically different from PC DOS or CP/M , which were more commonly used on the 8080- and 8088-based microcomputers of the time. A second offering, the DECmate II was the latest version of the PDP-8-based word processors, but not really suited to general computing, nor competitive with Wang Laboratories ' popular word processing equipment. The most popular early DEC microcomputer

3456-511: The Rainbow, and in its standard form was the first widely marketed diskless workstation . In 1984, DEC launched its first 10 Mbit/s Ethernet . Ethernet allowed scalable networking, and VAXcluster allowed scalable computing. Combined with DECnet and Ethernet-based terminal servers ( LAT ), DEC had produced a networked storage architecture which allowed them to compete directly with IBM. Ethernet replaced Token Ring , and went on to become

3552-492: The System Modules to build their "Memory Test" machine for testing core memory systems, selling about 50 of these pre-packaged units over the next eight years. The PDP-1 and LINC computers were also built using System Modules (see below). Modules were part of DEC's product line into the 1970s, although they went through several evolutions during this time as technology changed. The same circuits were then packaged as

3648-469: The TX-0 successfully proved the basic concepts, attention turned to a much larger system, the 36-bit TX-2 with a then-enormous 64 kWords of core memory . Core was so expensive that parts of TX-0's memory were stripped for the TX-2, and what remained of the TX-0 was then given to MIT on permanent loan. At MIT, Ken Olsen and Harlan Anderson noticed something odd: students would line up for hours to get

3744-436: The ability to address more memory, often by extending the address format to 18 or 24-bits in machines were otherwise similar to their earlier 16-bit designs. In contrast, DEC decided to make a more radical departure. In 1976, they began the design of a machine whose entire architecture was expanded from the 16-bit PDP-11 to a new 32-bit basis. This would allow the addressing of very large memories, which were to be controlled by

3840-515: The adoption of "\" for pathnames in MS-DOS and Microsoft Windows as opposed to "/" in Unix . The evolution of the PDP-11 followed earlier systems, eventually including a single-user deskside personal computer form, the MicroPDP-11. In total, around 600,000 PDP-11s of all models were sold, and a wide variety of third-party peripheral vendors had also entered the computer product ecosystem. It

3936-1243: 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. 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. In

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4032-512: The basis for the new design, although when they first viewed the proposal, management was not impressed and almost cancelled it. The result was the PDP-11 , released in 1970. It differed from earlier designs considerably. In particular, the new design did not include many of the addressing modes that were intended to make programs smaller in memory, a technique that was widely used on other DEC machines and CISC designs in general. This would mean

4128-451: The better-established vendors like IBM or Honeywell , in spite of its low cost around $ 300,000. Only 23 were sold, or 26 depending on the source, and unlike other models the low sales meant the PDP-6 was not improved with successor versions. However, the PDP-6 is historically important as the platform that introduced "Monitor", an early time-sharing operating system that would evolve into

4224-410: 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

4320-774: The company's first computer, the PDP-1 . In keeping with Doriot's instructions, the name was an initialism for " Programmable Data Processor ", leaving off the term "computer". As Gurley put it, "We aren't building computers, we're building 'Programmable Data Processors'." The prototype was first shown publicly at the Joint Computer Conference in Boston in December 1959. The first PDP-1 was delivered to Bolt, Beranek and Newman in November 1960, and formally accepted

4416-411: The compatible DECSYSTEM-20 , along with a TOPS-20 operating system that included virtual memory support. The Jupiter Project was supposed to continue the mainframe product line into the future by using gate arrays with an innovative Air Mover Cooling System, coupled with a built-in floating point processing engine called "FBOX". The design was intended for a top tier scientific computing niche, yet

4512-472: 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

4608-486: The critical performance measurement was based upon COBOL compilation which did not fully utilize the primary design features of Jupiter technology. When the Jupiter Project was cancelled in 1983, some of the engineers adapted aspects of the 36-bit design into a forthcoming 32-bit design, releasing the high-end VAX8600 in 1985. DEC's successful entry into the computer market took place during a fundamental shift in

4704-430: 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. 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

4800-485: 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 was ported to HP Alpha and Intel IA-64 ( Itanium ) CPU architectures, and now runs on x86-64 processors. 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 . The NonStop Kernel-based NonStop product line

4896-473: The fact that several competitors had just entered the market with machines aimed directly at the PDP-5's market space, which the PDP-8 trounced. This gave the company two years of unrestricted leadership, and eventually 1450 "straight eight" machines were produced before it was replaced by newer implementations of the same basic design. DEC hit an even lower price-point with the PDP-8/S, the S for "serial". As

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4992-475: The first "R" (red) series " Flip-Chip " modules. Later, other Flip-Chip module series provided additional speed, much higher logic density, and industrial I/O capabilities. DEC published extensive data about the modules in free catalogs that became very popular. With the company established and a successful product on the market, DEC turned its attention to the computer market once again as part of its planned "Phase II". In August 1959, Ben Gurley started design of

5088-487: The fledgling company change its business plan to focus less on computers, and even change their name from "Digital Computer Corporation". The pair returned with an updated business plan that outlined two phases for the company's development. They would start by selling computer modules as stand-alone devices that could be purchased separately and wired together to produce a number of different digital systems for lab use. Then, if these "digital modules" were able to build

5184-405: 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. Digital Equipment Corporation Digital Equipment Corporation ( DEC / d ɛ k / ), using the trademark Digital , was a major American company in the computer industry from

5280-411: The front of the modules. Three versions were offered, running at 5 MHz (1957), 500 kHz (1959), or 10 MHz (1960). The Modules proved to be in high demand by other computer companies, who used them to build equipment to test their own systems. Despite the recession of the late 1950s, the company sold $ 94,000 worth of these modules during 1958 alone (equivalent to $ 992,700 in 2023), turning

5376-413: The inspiration for many microcomputer OS's, as these were generally being written by programmers who cut their teeth on one of the many PDP-11 models. For example, CP/M used a command syntax similar to RT-11's, and even retained the awkward PIP program used to copy data from one computer device to another. As another historical footnote, DEC's use of "/" for "switches" (command-line options) would lead to

5472-490: The lab's various computer projects. The Lab is best known for their work on what would today be known as "interactivity", and their machines were among the first where operators had direct control over programs running in real-time. These had started in 1944 with the famed Whirlwind , which was originally developed to make a flight simulator for the US Navy , although this was never completed. Instead, this effort evolved into

5568-424: The late 1980s, especially with the introduction of RISC -based workstation machines, the performance niche of the minicomputer was rapidly eroded. By the early 1990s, the company was in turmoil as their mini sales collapsed and their attempts to address this by entering the high-end market with machines like the VAX 9000 were market failures. After several attempts to enter the workstation and file server market,

5664-594: 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. 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

5760-548: The limited information available, they used it to process radar cross section data for the Lockheed A-12 reconnaissance aircraft . Gordon Bell remembered that it was being used in Oregon some time later, but could not recall who was using it. In November 1962, DEC introduced the $ 65,000 PDP-4 . The PDP-4 was similar to the PDP-1 and used a similar instruction set, but used slower memory and different packaging to lower

5856-441: The lines were shut down in early 1967. Like the PDP-1 before it, the PDP-5 inspired a series of newer models based on the same basic design that would go on to be more famous than its parent. On March 22, 1965, DEC introduced the PDP-8 , which replaced the PDP-5's modules with the new R-series modules using Flip Chips. The machine was re-packaged into a small tabletop case, which remains distinctive for its use of smoked plastic over

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5952-496: The machine would cost much less than the larger systems then available, it would also be able to serve users that needed a lower-cost solution dedicated to a specific task, where a larger 36-bit machine would not be needed. In 1957, when the pair and Ken's brother Stan sought capital, they found that the American business community was hostile to investing in computer companies. Many smaller computer companies had come and gone in

6048-438: The machine would spend more time accessing memory, which would slow it down. However, the machine also extended the idea of multiple "General Purpose Registers" (GPRs), which gave the programmer flexibility to use these high-speed memory caches as they needed, potentially addressing the performance issues. A major advance in the PDP-11 design was DEC's Unibus , which supported all peripherals through memory mapping . This allowed

6144-423: 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

6240-481: The modern definition. Its introductory price of $ 18,500 (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. Follow-on versions using small scale integrated circuits further lowered the cost and size of the system. Its success led to widespread imitation, and

6336-496: 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

6432-425: The name implies the /S used a serial arithmetic unit, which was much slower but reduced costs so much that the system sold for under $ 10,000. DEC then used the new PDP-8 design as the basis for a new LINC, the two-processor LINC-8 . The LINC-8 used one PDP-8 CPU and a separate LINC CPU, and included instructions to switch from one to the other. This allowed customers to run their existing LINC programs, or "upgrade" to

6528-547: 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 provided solutions for those looking for multi-user systems. The introduction of

6624-458: The next April. The PDP-1 sold in basic form for $ 120,000 (equivalent to $ 9,269,291 in 2023). By the time production ended in 1969, 53 PDP-1s had been delivered. The PDP-1 was supplied standard with 4096 words of core memory , 18-bits per word, and ran at a basic speed of 100,000 operations per second. It was constructed using many System Building Blocks that were packaged into several 19-inch racks . The racks were themselves packaged into

6720-581: The price. Like the PDP-1, about 54 PDP-4s were eventually sold, most to a customer base similar to the original PDP-1. In 1964, DEC introduced its new Flip Chip module design, and used it to re-implement the PDP-4 as the PDP-7 . The PDP-7 was introduced in December 1964, and about 120 were eventually produced. An upgrade to the Flip Chip led to the R series, which in turn led to the PDP-7A in 1965. The PDP-7

6816-607: The same design. During construction of the prototype PDP-1, some design work was carried out on a 24-bit PDP-2, and the 36-bit PDP-3. Although the PDP-2 never proceeded beyond the initial design, the PDP-3 found some interest and was designed in full. Only one PDP-3 appears to have been built, in 1960, by the CIA's Scientific Engineering Institute (SEI) in Waltham, Massachusetts . According to

6912-449: 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

7008-471: 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. UNIX was originally a minicomputer OS, while the Windows NT kernel ,

7104-492: The term "first minicomputer". Most computing histories point to the 1964 introduction of Digital Equipment Corporation 's (DEC) 12-bit PDP-8 as the first minicomputer. Some of this is no doubt due to DEC's widespread use of the term starting in the mid-1960s. Smaller systems, including those from DEC like the PDP-5 and LINC , 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

7200-403: 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. Around

7296-468: The two-decade lifetime of the minicomputer class (1965–1985), almost 100 companies formed and only a half dozen remained. 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"

7392-505: The ubiquitous Teletype Model 33 ASR. They usually took up one or a few 19-inch rack cabinets, compared with the large mainframes that could fill a room. 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

7488-489: The underlying organization of the machines from word lengths based on 6-bit characters to those based on 8-bit words needed to support ASCII . DEC began studies of such a machine, the PDP-X, but Ken Olsen did not support it as he could not see how it offered anything their existing 12-bit or 18-bit machines didn't. This led the leaders of the PDP-X project to leave DEC and start Data General , whose 16-bit Data General Nova

7584-467: The widely used TOPS-10 . When newer Flip Chip packaging allowed the PDP-6 to be re-implemented at a much lower cost, DEC took the opportunity to refine their 36-bit design, introducing the PDP-10 in 1968. The PDP-10 was as much a success as the PDP-6 was a commercial failure; about 700 mainframe PDP-10s were sold before production ended in 1984. The PDP-10 was widely used in university settings, and thus

7680-471: Was "the world’s first commercially produced minicomputer". 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. 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,

7776-434: 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

7872-555: Was accomplished with different CPU modules and firmware. VAXserver models include: This computer hardware article is a stub . You can help Misplaced Pages by expanding it . Minicomputers 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

7968-478: Was either bought from the company that built the computer or custom-constructed for one client. However, the emerging third-party software industry disregarded the PDP-11/Professional line and concentrated on other microcomputers where distribution was easier. At DEC itself, creating better programs for the Professional was not a priority, perhaps from fear of cannibalizing the PDP-11 line. As a result,

8064-507: Was even sold in kit form as the Heathkit H11 , although it proved too expensive for Heathkit 's traditional hobbyist market. The introduction of semiconductor memory in the early 1970s, and especially dynamic RAM shortly thereafter, led to dramatic reductions in the price of memory as the effects of Moore's Law were felt. Within years, it was common to equip a machine with all the memory it could address, typically 64 KB on 16-bit machines. This led vendors to introduce new designs with

8160-623: Was eventually ported along with MS-DOS 2.0 and introduced in late 1983. Although the Rainbow generated some press, it was unsuccessful due to its high price and lack of marketing and sales support. By late 1983 IBM was outselling DEC's personal computers by more than ten to one. A further system was introduced in 1986 as the VAXmate , which included Microsoft Windows 1.0 and used VAX/VMS-based file and print servers along with integration into DEC's own DECnet -family, providing LAN/WAN connection from PC to mainframe or supermini. The VAXmate replaced

8256-509: Was focused on the enterprise market and had recently purchased several other large vendors. DEC was a major player overseas where Compaq had less presence. However, Compaq had little idea what to do with its acquisitions, and soon found itself in financial difficulty of its own. Compaq subsequently merged with Hewlett-Packard (HP) in May 2002. Ken Olsen and Harlan Anderson were two engineers who had been working at MIT Lincoln Laboratory on

8352-636: Was followed by the even more successful VT100 and its follow-ons, making DEC one of the largest terminal vendors in the industry. This was supported by a line of inexpensive computer printers , the DECwriter line. With the VT and DECwriter series, DEC could now offer a complete top-to-bottom system from computer to all peripherals, which formerly required collecting the required devices from different suppliers. The VAX processor architecture and family of systems evolved and expanded through several generations during

8448-731: Was initially available only to DEC employees. It was only after IBM had successfully launched the IBM PC in 1981 that DEC responded with their own systems. In 1982, DEC introduced not one, but three incompatible machines which were each tied to different proprietary architectures. The first, the DEC Professional , was based on the PDP-11/23 (and later, the 11/73) running the RSX-11M+ derived, but menu-driven, P/OS ("Professional Operating System"). This DEC machine easily outperformed

8544-498: Was launched, effectively a PDP-8 on a chip. This was a way to allow PDP-8 software to be run even after the official end-of-life announcement for the DEC PDP-8 product line. While the PDP-5 introduced a lower-cost line, 1963's PDP-6 was intended to take DEC into the mainframe market with a 36-bit machine. However, the PDP-6 proved to be a "hard sell" with customers, as it offered few obvious advantages over similar machines from

8640-541: 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 CPU performance equal to low-end and mid-range minis, and

8736-417: 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

8832-539: Was released in 1969 and was a huge success. The success of the Nova finally prompted DEC to take the switch seriously, and they began a crash program to introduce a 16-bit machine of their own. The new system was designed primarily by Harold McFarland, Gordon Bell , Roger Cady, and others. The project was able to leap forward in design with the arrival of Harold McFarland, who had been researching 16-bit designs at Carnegie Mellon University . One of his simpler designs became

8928-404: Was the PDP-11's first disk operating system, but was soon supplanted by more capable systems. RSX provided a general-purpose multitasking environment and supported a wide variety of programming languages . IAS was a time-sharing version of RSX-11D. Both RSTS and Unix were time-sharing systems available to educational institutions at little or no cost, and these PDP-11 systems were destined to be

9024-454: Was the basis of many advances in computing and operating system design during the 1970s. DEC later re-branded all of the models in the 36-bit series as the "DECsystem-10", and PDP-10s are generally referred to by the model of their CPU, starting with the "KA10", soon upgraded to the "KI10" (I:Integrated circuit); then to "KL10" (L:Large-scale integration ECL logic ); also the "KS10" (S: Small form factor ). Unified product line upgrades produced

9120-484: Was the dual-processor (Z80 and 8088) Rainbow 100 , which ran the 8-bit CP/M operating system on the Z80 and the 16-bit CP/M-86 operating system on the Intel 8088 processor. It could also run a UNIX System III implementation called VENIX . Applications from standard CP/M could be re-compiled for the Rainbow, but by this time users were expecting custom-built (pre-compiled binary) applications such as Lotus 1-2-3 , which

9216-441: Was used as a printer . The Soroban system was notoriously unreliable, and often replaced with a modified Friden Flexowriter , which also contained its own punched tape system. A variety of more-expensive add-ons followed, including magnetic tape systems, punched card readers and punches, and faster punched tape and printer systems. When DEC introduced the PDP-1, they also mentioned larger machines at 24, 30 and 36 bits, based on

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