Digital Equipment Corporation
Encyclopedia
Digital Equipment Corporation was a major American company in the computer industry
and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s. Also known as DEC and using the trademark DIGITAL, its PDP
and VAX
products were the most successful (in terms of sales) minicomputer
s.
From 1957 until 1992 its headquarters was located in a former wool mill at Clock Tower Place, Maynard, Massachusetts
. DEC was acquired in June 1998 by Compaq
, which subsequently merged with Hewlett-Packard
in May 2002. Some parts of DEC, notably the compiler business and the Hudson, Massachusetts
facility, were sold to Intel.
Digital Equipment Corporation should not be confused with the unrelated companies Digital Research, Inc
or Western Digital
(despite the latter manufacturing the LSI-11 chipsets used in DEC's low end PDP-11
/03 computers).
, widely considered to be the first successful minicomputer
. Looking to simplify and update their line, DEC replaced most of their smaller machines with the PDP-11
in 1970, eventually selling over 600,000 units and cementing DECs position in the industry. Originally designed as a follow-on to the PDP-11, DEC's VAX-11
series was the first widely used 32-bit
minicomputer, sometimes referred to as "superminis". These were able to compete in many roles with larger mainframe computer
s, such as the IBM System/370. The VAX was a best-seller, with over 400,000 sold, and its sales through the 1980s propelled the company into the second largest in the industry. At its peak, DEC was the second largest employer in Massachusetts, second only to the state government.
The rapid rise of the business microcomputer
in the late 1980s, and especially the introduction of powerful 32-bit systems in the 1990s, quickly eroded the value of DEC's systems. DEC's last major attempt to find a space in the rapidly changing market was the DEC Alpha
64-bit
RISC processor architecture. DEC initially started work on Alpha as a way to re-implement their VAX series, but also employed it in a range of high-performance workstations. Although the Alpha processor family met both of these goals, and, for most of its lifetime, was the fastest processor family on the market, it did little to affect the bottom line or repair the company's status.
The company was acquired in June 1998 by Compaq
, in what was at that time the largest merger in the history of the computer industry. At the time, Compaq 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. The company subsequently merged with Hewlett-Packard
in May 2002. some of DEC's product lines were still produced under the HP name.
Ken Olsen
and Harlan Anderson
were two engineers who had been working at MIT Lincoln Laboratory
on 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 the SAGE
system for the US Air Force, which used large screens and light gun
s 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 transistor
s in place of vacuum tube
s. 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 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, Olsen and Anderson noticed something odd: students would line up for hours to get 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 graphical output or realtime operation would be more important than outright performance. Additionally, as 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 wouldn't be needed.
In 1957 when the pair and Ken's brother Stan went looking for capital, they found that the American business community was hostile to investing in computer companies. Many smaller computer companies had come and gone in 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 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 module
s 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 a self-sustaining business, the company would be free to use them to develop a complete computer in their Phase II. The newly christened DEC 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, 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. They were then connected together using banana plug patch cords inserted at 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 in 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, turning a profit at the end of its first year.
The original Laboratory Modules were soon supplemented with the "Digital Systems 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 inserting them into a custom 19-inch rack
. These versions allowed 25 modules be to inserted into a single 5-1/4 inch section of racking, and allowed the high densities needed to build a computer. DEC used the Systems 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.
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 the first "R" (red) series "Flip-Chip
" modules. Later, other module series provided additional speed, much higher logic density, and industrial I/O capabilities. Digital published extensive data about the modules in free catalogs that became very popular.
. 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 the next April. The PDP-1 sold in basic form for $120,000, or about $900,000 in 2011 US dollars. 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-bit
s 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 a single large mainframe case, with a hexagonal control panel containing switches and lights mounted to lay at table-top height at one end of the mainframe. Above the control panel was the system's standard input/output
solution, a punch 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 was used as a printer. The Soroban system was notoriously unreliable, and often replaced with a modified Friden Flexowriter
, which also contained its own punch tape system. A variety of more-expensive add-ons followed, including magnetic tape
systems, punched card
readers and punches, and faster punch tape and printer systems.
When DEC introduced the PDP-1, they also mentioned larger machines at 24, 30 and 36-bits, based on 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 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 the price. Like the PDP-1, about 54 PDP-4's 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 is most famous as the original machine for the Unix
operating system.
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, 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 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.
used 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 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 11 August 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 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 22 March 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 the CPU which allowed one to easily see the wire-wrapped internals 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 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 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 the PDP-8, all in software. Although not a huge seller, 142 LINK-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 Digital and Intersil
, the Intersil 6100
chip 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 Digital 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 advantages over similar machines from 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 earlier models the low sales meant the PDP-6 was not improved with intermediate versions. However, the PDP-6 is historically important as the platform that introduced "Monitor", an early time-sharing
operating system
that would evolve into the widely used TOPS-10
.
In spite of the PDP-6's limited commercial success, it introduced many features that clearly had commercial benefit. When the Flip Chip packaging allowed the PDP-6 to be re-implemented at a much lower cost, DEC took the opportunity to carry out a similar evolution of their 36-bit design and introduced the PDP-10
in 1968. The PDP-10 was as much a success as the PDP-6 was a failure; during its lifetime about 700 mainframe PDP-10s were sold before production ended in 1984. The PDP-10 was widely used in university settings, and thus 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, like "KA10". Later upgrades produced the compatible DECSYSTEM-20
, along with TOPS-20
that included virtual memory
.
. The DECtape was a length of special 3/4-inch wide magnetic tape wound on 5-inch reels. The recording format was a 10-track approach using fixed-length numbered 'blocks' organized into a standard file structure, including a directory. Files could be written, read, changed, and deleted on a DECtape as though it were a disk drive. For greater efficiency, the DECtape drive could read and write to a DECtape in both directions.
In fact, some PDP-10 systems had no disks at all, using DECtapes alone for their primary data storage. The DECtape was also widely used on other PDP models, since it was much easier to use than hand-loading multiple paper tapes. Primitive early time-sharing systems could use DECtapes as system devices and swapping devices. Although superior to paper tape, DECtapes were relatively slow, and were supplanted as reliable disk drives became affordable.
s instead of 6-bit characters. Known as the "PDP-X", the project was eventually cancelled. Several team members decamped and set up Data General
in May 1968, and rapidly brought the 16-bit NOVA
minicomputer to market. DEC immediately found itself behind in the industry transition to 8-bit bytes, and soon lost its crown as the largest minicomputer vendor.
The PDP-11
16-bit computer was designed in a crash program 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 the PDP-11, although when they first viewed the proposal, management was not impressed and almost cancelled it.
In particular, the new design did not include many of the addressing mode
s 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 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 Digital's Unibus
, which supported all peripherals through memory mapping
. This allowed a new device to be added easily, generally only requiring plugging a hardware interface board into the 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 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 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 language
s. 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 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
became DEC's largest customer.
RT-11 provided a practical real-time operating system in minimal memory, allowing the PDP-11 to continue Digital's critical role as a computer supplier for embedded system
s. Historically, RT-11 also served as 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 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-11's of all models were sold. and a wide variety of third-party peripheral vendors had also entered the computer product ecosystem.
Many PDP-11-like machines were also introduced by competitors. The PDP-11 series was cloned in COMECON countries as the SM EVM
series, and was produced in quantities comparable to original PDP-11 production.
architecture to 32-bit
s while adding a complete virtual memory
system to the simple paging and memory protection of the PDP-11. The result was the VAX
architecture. The first computer to use a VAX CPU was the VAX-11/780, 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 a successor to the PDP-10 mainframe, and instead focused on promoting the VAX as their the single computer architecture for the company.
Supporting the VAX's success was the VT52
, one of the most successful smart terminal
s. 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 chassis. The VT52 was followed by the even more successful VT100
and its follow-ons, making DEC one of the largest terminal vendors in the industry. With the VT 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 the 1980s, culminating in the NVAX
microprocessor
implementation and VAX 7000/10000
series in the early 1990s.
s inevitably led to the first microcomputers around 1975. At the time these systems were of limited utility, and Ken Olsen famously derided them in 1977, stating "There 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. 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 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, Digital 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 the PC, but was more expensive than, and completely incompatible with IBM PC hardware and software, offering far fewer options for customizing a system. 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 best known of DEC's early microcomputers was the Rainbow 100
, which ran an implementation of CP/M
on the Intel 8086
processor. 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 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.
The way the DEC standard RX50 floppy disk drive supported DEC's initial offerings seemed to encapsulate their approach to the personal computer market. Although the mechanical drive hardware was nearly identical to other 5.25" floppy disk drives available on competing systems, DEC sought to differentiate their product by using a proprietary disk format for the data written on the disk. The DEC format had a higher capacity for data, but the RX50 drives were incompatible with other PC floppy drives. This required DEC owners to buy higher-priced, specially-formatted floppy media, which was harder to obtain through standard distribution channels. DEC attempted to enforce exclusive control over its floppy media sales by copyright
ing its proprietary disk format, and requiring a negotiated license agreement and royalty payments from anybody selling compatible media. The proprietary data format meant that RX50 floppies were not interchangeable with other PC floppies, further isolating DEC products from the developing de facto standard PC market. Hardware hackers and DEC enthusiasts eventually reverse-engineered the RX50 format, but the damage had already been done, in terms of market confusion and isolation.
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 the Rainbow, and in its standard form was the first widely marketed diskless workstation.
. 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 the dominant networking model in use today.
In September 1985, DEC became the fifth company to register a .com
domain name
(dec.com).
Along with the hardware and protocols, DEC also introduced the VAXcluster concept, which allowed several VAX machines to be tied together into a single larger storage system. VAXclusters allowed a DEC-based company to scale their services by adding new machines to the cluster at any time, as opposed to buying a faster machine and using that to replace a slower one. The flexibility this offered was compelling, and allowed DEC to attack high-end markets formerly out of their reach.
At its peak, Digital was the second-largest computer company in the world, with over 100,000 employees. It was during this time that the company branched out development into a wide variety of projects that were far from its core business in computer equipment. The company invested heavily in custom software. In the 1970s and earlier most software was custom-written to serve a specific task, but by the 1980s the introduction of relational databases and similar systems allowed powerful software to be built in a modular fashion, potentially saving enormous amounts of development time. Software companies like Oracle
became the new darlings of the industry, and DEC started their own efforts in every "hot" niche, in some cases several projects for the same niche. Some of these products competed with DEC's own partners, notably Rdb
which competed with Oracle's products on the VAX, part of a major partnership only a few years earlier.
Although many of these products were well designed, most of them were DEC-only or DEC-centric, and customers frequently ignored them and used third-party products instead. This problem was further exacerbated by Olsen's aversion to traditional advertising and his belief that well-engineered products would sell themselves. Hundreds of millions of dollars were spent on these projects, at the same time that workstations using RISC microprocessors were starting to approach VAX CPUs in performance.
and Stanford MIPS
designs were aiming to introduce 32-bit designs that would outperform the fastest members of the VAX family, DEC's cash cow
.
Constrained by the huge success of their VAX
/VMS
products, which followed the proprietary model, the company was very late to respond to these threats. In the early 1990s, DEC found its sales faltering and its first layoffs followed. The company that created the minicomputer, a dominant networking technology, and arguably the first computers for personal use, had abandoned the "low end" market, whose dominance with the PDP-8 had built the company in a previous generation. Decisions about what to do about this threat led to infighting within the company that seriously delayed their responses.
One group suggested that every possible development in the industry be poured into the construction of a new VAX family that would leapfrog the performance of the existing machines. This would limit the market erosion in the top-end segment, where profit margin
s were maximized and DEC could continue to survive as a minicomputer vendor. This line of thought led, eventually, to the VAX 9000
series, which were plagued with problems when they were first introduced in October 1989, already two years late. The problems took so long to work out, and the prices of the systems were so high, that DEC was never able to make the line the success they hoped.
Others within the company felt that the proper response was to introduce their own RISC designs and use those to build new machines. However, there was little official support for these efforts, and no less than four separate small projects ran in parallel at various labs around the US. Eventually these were gathered into the DEC PRISM
project, which delivered a credible 32-bit design with some unique features allowing it to serve as the basis of a new VAX implementation. Infighting with teams dedicated to DEC's big iron made funding difficult, and the design was not finalized until April 1988, and then cancelled shortly thereafter.
Another group concluded that new workstation
s like those from Sun Microsystems
and Silicon Graphics
would take away a large part of DEC's existing customer base before the new VAX systems could address the issues, and that the company needed its own Unix workstation as soon as possible. Fed up with slow progress on both the RISC and VAX fronts, a group in Palo Alto
started a skunkworks project
to introduce their own systems. Selecting the MIPS processor, which was widely available, introducing the new DECstation
series with the model 3100 on 11 January 1989. These systems would see some success in the market, but were later displaced by similar models running the Alpha.
processor, the first implementation of their Alpha
instruction set architecture, initially named Alpha AXP (the "AXP" was a "non-acronym" and was later dropped). This was a 64-bit
RISC architecture (as opposed to the 32-bit CISC
architecture used in the VAX) and one of the first "pure" (not an extension of an earlier 32-bit architecture) 64-bit microprocessor
architectures and implementations. The Alpha offered class-leading performance at its launch, and subsequent variants continued to do so into the 2000s. An AlphaServer SC45 supercomputer was still ranked No. 6 in the world in November 2004. Alpha-based computers (the DEC AXP series, later the AlphaStation
and AlphaServer
series) superseded both the VAX and MIPS architecture in DEC's product lines, and could run OpenVMS
, DEC OSF/1 AXP (later, Digital Unix or Tru64 UNIX) and Microsoft's then-new operating system, Windows NT
.
In 1998, following the takeover by Compaq Computers, a decision was made that Microsoft would no longer support and develop Windows NT for the Alpha series computers, a decision that was seen as the beginning of the end for the Alpha series computers.
DEC tried to compete in the Unix market by adding POSIX
-compatibility features to the VAX/VMS operating system (becoming "OpenVMS") and by selling its own version of Unix (Ultrix
on PDP-11, VAX and MIPS architectures; OSF/1 on Alpha), and began to advertise more aggressively. DEC was simply not prepared to sell into a crowded Unix market however, and the low end PC-servers running NT (based on Intel processors) took market share from Alpha-based computers. DEC's workstation and server line never gained much popularity beyond former DEC customers.
microprocessor. This was based in part on ARM7 and in part on DEC technologies like Alpha, and was targeted at embedded system
s and portable devices. It was highly compatible with the ARMv4 architecture and was very successful, competing effectively against rivals such as the SuperH
and MIPS architecture
s in the portable digital assistant market. Microsoft
subsequently dropped support for these other architectures in their Pocket PC
platform. In 1997, as part of a lawsuit settlement, the StrongARM
intellectual property was sold to Intel. They continued to produce StrongARM
, as well as developing it into the XScale
architecture. Intel subsequently sold this business to Marvell Technology Group
in 2006.
was replaced by Robert Palmer
as the company's president. Digital's board of directors also granted Palmer the title of chief executive officer ("CEO"), a title that had never been used during Digital's 35-year existence. Palmer had joined DEC in 1985 to run Semiconductor Engineering and Manufacturing. His relentless campaign to be CEO, and success with the Alpha microprocessor family, made him a candidate to succeed Olsen. At the same time a more modern logo was designed
During the profitable years up until the early 1990s, DEC was a company that boasted that it never had a general layoff; following the 1992 economic downturn, layoffs became regular events as the company continually downsized to try to stay afloat. Palmer was tasked with the goal of bringing DEC back to profitability, which he attempted to do by changing the established DEC business culture, hiring new executives from outside the company, and selling off various non-core business units:
By 1997 Digital had subsidiary companies in more than two dozen countries including Austria, Australia, Belgium, Brazil, Canada, China (People's Republic), Colombia, Cyprus, Czech Republic, Denmark, Finland, France, Germany, Ireland, Israel, Japan, Jersey States, New Zealand, Netherlands, Norway, Russia, Singapore, Spain, Sweden, Switzerland, Taiwan, and the United Kingdom.
Eventually, on 26 January 1998, what remained of the company (including Digital's multivendor global services organization and customer support centers) was sold to Compaq
, which was acquired by Hewlett-Packard
in 2002. The remainder of Digital Semiconductor (the Alpha microprocessor group) was sold to Intel, which placed those employees back in their Hudson, Mass. office which they had vacated when the site was sold to Intel in 1997. Compaq, and later HP, continued to sell many of the former Digital products but rebranded with their own logos. For example, HP now sells what were formerly Digital's StorageWorks disk/tape products, as a result of the Compaq acquisition.
The Digital logo survived for a while after the company ceased to exist, as the logo of Digital GlobalSoft, an IT services company in India (which was a 51 percent subsidiary of Compaq). Digital GlobalSoft was later renamed "HP GlobalSoft" (also known as the "HP Global Delivery India Center" or HP GDIC) and no longer uses the Digital logo.
The digital.com and DEC.com domain names are now owned by Hewlett-Packard and redirect to their US website. Digital once held the Class A
IP address
block 16.0.0.0/8.
The Digital Federal Credit Union
(DCU, now DFCU), which was chartered in 1979 for employees of DEC, is now open to essentially everyone. DFCU has over 700 different sponsors, including the companies that acquired pieces of DEC.
and are still operated by Hewlett-Packard
. The laboratories were:
Some of the former employees of Digital's Research Labs or Digital's R&D in general include:
Some of the former employees of Digital Equipment Corp who were responsible for developing Alpha and StrongARM
Some of the work of the Research Labs was published in the Digital Technical Journal, which was in published from 1985 until 1998.
standards, especially the ASCII
character set, which survives in Unicode
and the ISO 8859 character set family. Digital's own Multinational Character Set
also had a large influence on ISO 8859-1 (Latin-1) and, by extension, Unicode
.
The first versions of the C
language and the Unix
operating system ran on Digital's PDP
series of computers (first on a PDP-7, then the PDP-11
's), which were among the first commercially viable minicomputer
s, although for several years Digital itself did not encourage the use of Unix.
Digital also produced the popular VAX
computer family, the first pure 64-bit microprocessor architecture (Alpha AXP
), the first commercially successful workstation (the VT-78), and some commercially unsuccessful personal computers. The central computing system of the Soviet reusable Buran spaceship was based on two MicroVAX computers.
Digital produced widely used interactive operating systems, including OS-8
, TOPS-10
, TOPS-20
, RSTS/E
, RSX-11
, RT-11
, and OpenVMS
. PDP computers, in particular the PDP-11
model, inspired a generation of programmers and software developers. Some PDP-11
systems more than 25 years old (software and hardware) are still being used to control and monitor factories, transportation systems and nuclear plants. Digital was an early champion of time-sharing
systems.
Digital was to the command-line interface (CLI) what Apple was to the GUI : there was history before and innovation after, but it was Digital's operating systems that put it together in a complete and definitive form . The command-line interfaces found in Digital's systems, eventually codified as DCL
, would look familiar to any user of modern microcomputer CLIs; those used in earlier systems, such as CTSS, IBM
's JCL
, or Univac
's time-sharing systems, would look utterly alien. Many features of the CP/M and MS-DOS CLI show a recognizable family resemblance to Digital's OSes, including command names such as DIR and HELP and the "name-dot-extension" file naming conventions.
VAX and MicroVAX
computers (very widespread in the 1980s) running VMS formed one of the most important proprietary networks, DECnet
, which linked business and research facilities. The DECnet
protocols formed one of the first peer-to-peer networking standards, with DECnet phase I being released in the mid-1970s. Email, file sharing, and distributed collaborative projects existed within the company long before their value was recognized in the market.
Digital, Intel and Xerox through their collaboration to create the DIX standard, were champions of Ethernet
, but Digital is the company that made Ethernet commercially successful. Initially, Ethernet-based DECnet and LAT
protocols interconnected VAXes with DECserver terminal servers. Starting with the UNIBUS to Ethernet adapter, multiple generations of Ethernet controllers from Digital were the de facto standard. The CI "computer interconnect" adapter was the industry's first network interface controller to use separate transmit and receive "rings".
Digital also invented clustering, an operating system technology that treated multiple machines as one logical entity. Clustering permitted sharing of pooled disk and tape storage via the HSC50/70/90 and later series of Hierarchical Storage Controllers. HSCs delivered the first hardware RAID 0 and 1 capabilities and the first serial interconnects of multiple storage technologies. This technology was the forerunner to systems like Network of Workstations which are used for massively cooperative tasks such as web-searches and drug research.
The LA36 and LA120 dot matrix printers became industry standards and may have hastened the demise of the Teletype Corporation
.
The VT100
computer terminal
became the industry standard, implementing a useful subset of the ANSI X3.64 standard, and even today terminal emulators such as HyperTerminal
, PuTTY
and Xterm
still emulate a VT100 (or its more capable successor, the VT220
).
The X Window System
, the network transparent window system used on UNIX and Linux, and also available on other operating systems, was developed at MIT
jointly between Project Athena
and the Laboratory for Computer Science. Digital was the primary sponsor for this project, which was one of the first large scale free software projects, a contemporary of the GNU Project
but not associated with it.
Dave Cutler
, who led the development of RSX-11
M, RSX-11
M+, VMS and then VAXeln
, left Digital in 1988 to lead the development of Windows NT
which was initially intended to be an "open" operating system
that would run on more powerful processors than the existing predominant x86 architecture. While DEC did see value in continuing its X Window System
environment to support engineering customers, it understood that future mid-range based customers would demand a faster and more user friendly Graphical User Interface
(GUI), potentially offered through the Windows environment. As Microsoft had experience, technology and patents that would give them upper hand in advancing GUI technology, DEC opted to partner with Microsoft's development of Windows NT for mid-range processors and share in the R&D process of creating faster computers using their RISC Alpha
processors. Microsoft was not exclusively bound to the Alpha chip so it pursued other processor makers such as IBM with the PowerPC
architecture and eventually capitalized on the emerging strength of the Intel x86 based processors. While most would say that the market determined its own course through the more cost efficient processors produced by Intel, DEC quickly came to realize that its loose partnership with Microsoft would lead to its own undoing in terms of being a major player in the mid-range processor market.
Notes-11 and its follow-on product, VAXnotes, were two of the first examples of online collaboration software, a category that has become to be known as groupware
. Len Kawell
, one of the original Notes-11 developers later joined Lotus Development Corporation and contributed to their Lotus Notes
product.
Digital was one of the first businesses connected to the Internet with dec.com, registered in 1985, being one of the first of the now ubiquitous .com domains. gatekeeper.dec.com was a well-known software repository during the pre-World Wide Web days, and Digital was also the first computer vendor to open a public website, on 1 October 1993. The popular AltaVista
, created by Digital, was one of the first comprehensive Internet search engines. (Although Lycos
was earlier, it was much more limited.)
DEC invented Digital Linear Tape
(DLT), formerly known as CompacTape, which began as a compact backup medium for MicroVAX systems, and later grew to capacities of 800 gigabytes.
Work on the first hard-disk-based MP3-player, the Personal Jukebox
, started at the DEC Systems Research Center
. (The project was started about a month before the merger into Compaq
was completed.)
DEC's Western Research Lab created the Itsy Pocket Computer
. This was developed into the Compaq iPaq
line of PDA
s, which replaced the Compaq Aero
PDA.
was called DECUS
(Digital Equipment Computer User Society) during the 1960s to 1990s. When Compaq
acquired Digital in 1998, the users group was renamed CUO, the Compaq Users' Organisation. When HP
acquired Compaq
in 2002, CUO became HP-Interex
, although there are still DECUS groups in several countries. In the United States, the organization is represented by the Encompass
organization.
Computer industry
Computer industry is a collective term used to describe the whole range of businesses involved in developing computer software, designing computer hardware and computer networking infrastructures, the manufacture of computer components and the provision of information technology services.-See...
and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s. Also known as DEC and using the trademark DIGITAL, its PDP
Programmed Data Processor
Programmed Data Processor was the name of a series of minicomputers made by Digital Equipment Corporation. The name 'PDP' intentionally avoided the use of the term 'computer' because, at the time of the first PDPs, computers had a reputation of being large, complicated, and expensive machines, and...
and VAX
VAX
VAX was an instruction set architecture developed by Digital Equipment Corporation in the mid-1970s. A 32-bit complex instruction set computer ISA, it was designed to extend or replace DEC's various Programmed Data Processor ISAs...
products were the most successful (in terms of sales) minicomputer
Minicomputer
A minicomputer is a class of multi-user computers that lies in the middle range of the computing spectrum, in between the largest multi-user systems and the smallest single-user systems...
s.
From 1957 until 1992 its headquarters was located in a former wool mill at Clock Tower Place, Maynard, Massachusetts
Maynard, Massachusetts
Maynard is a town in Middlesex County, Massachusetts, United States. As of the 2010 census, the town population was 10,106.- History :Maynard, located on the Assabet River, was incorporated as an independent municipality in 1871. Prior to that it was known as 'Assabet Village' but was legally...
. DEC was acquired in June 1998 by Compaq
Compaq
Compaq Computer Corporation is a personal computer company founded in 1982. Once the largest supplier of personal computing systems in the world, Compaq existed as an independent corporation until 2002, when it was acquired for US$25 billion by Hewlett-Packard....
, which subsequently merged with Hewlett-Packard
Hewlett-Packard
Hewlett-Packard Company or HP is an American multinational information technology corporation headquartered in Palo Alto, California, USA that provides products, technologies, softwares, solutions and services to consumers, small- and medium-sized businesses and large enterprises, including...
in May 2002. Some parts of DEC, notably the compiler business and the Hudson, Massachusetts
Hudson, Massachusetts
Hudson is a town in Middlesex County, Massachusetts, United States. The population was 19,063 at the 2010 census. The town is located in central Massachusetts, about a 40-minute drive, or about , west of Boston, and about a 20-minute drive, or about , northeast of Worcester.Before its...
facility, were sold to Intel.
Digital Equipment Corporation should not be confused with the unrelated companies Digital Research, Inc
Digital Research
Digital Research, Inc. was the company created by Dr. Gary Kildall to market and develop his CP/M operating system and related products. It was the first large software company in the microcomputer world...
or Western Digital
Western Digital
Western Digital Corporation is one of the largest computer hard disk drive manufacturers in the world. It has a long history in the electronics industry as an integrated circuit maker and a storage products company. Western Digital was founded on April 23, 1970 by Alvin B...
(despite the latter manufacturing the LSI-11 chipsets used in DEC's low end PDP-11
PDP-11
The PDP-11 was a series of 16-bit minicomputers sold by Digital Equipment Corporation from 1970 into the 1990s, one of a succession of products in the PDP series. The PDP-11 replaced the PDP-8 in many real-time applications, although both product lines lived in parallel for more than 10 years...
/03 computers).
Overview
Initially focusing on the small-end of the computer market allowed DEC to grow without its potential competitors making serious efforts to compete with them. Their PDP series of machines became popular in the 1960s, especially the PDP-8PDP-8
The 12-bit PDP-8 was the first successful commercial minicomputer, produced by Digital Equipment Corporation in the 1960s. DEC introduced it on 22 March 1965, and sold more than 50,000 systems, the most of any computer up to that date. It was the first widely sold computer in the DEC PDP series of...
, widely considered to be the first successful minicomputer
Minicomputer
A minicomputer is a class of multi-user computers that lies in the middle range of the computing spectrum, in between the largest multi-user systems and the smallest single-user systems...
. Looking to simplify and update their line, DEC replaced most of their smaller machines with the PDP-11
PDP-11
The PDP-11 was a series of 16-bit minicomputers sold by Digital Equipment Corporation from 1970 into the 1990s, one of a succession of products in the PDP series. The PDP-11 replaced the PDP-8 in many real-time applications, although both product lines lived in parallel for more than 10 years...
in 1970, eventually selling over 600,000 units and cementing DECs position in the industry. Originally designed as a follow-on to the PDP-11, DEC's VAX-11
VAX
VAX was an instruction set architecture developed by Digital Equipment Corporation in the mid-1970s. A 32-bit complex instruction set computer ISA, it was designed to extend or replace DEC's various Programmed Data Processor ISAs...
series was the first widely used 32-bit
32-bit
The range of integer values that can be stored in 32 bits is 0 through 4,294,967,295. Hence, a processor with 32-bit memory addresses can directly access 4 GB of byte-addressable memory....
minicomputer, sometimes referred to as "superminis". These were able to compete in many roles with larger mainframe computer
Mainframe computer
Mainframes are powerful computers used primarily by corporate and governmental organizations for critical applications, bulk data processing such as census, industry and consumer statistics, enterprise resource planning, and financial transaction processing.The term originally referred to the...
s, such as the IBM System/370. The VAX was a best-seller, with over 400,000 sold, and its sales through the 1980s propelled the company into the second largest in the industry. At its peak, DEC was the second largest employer in Massachusetts, second only to the state government.
The rapid rise of the business microcomputer
Microcomputer
A microcomputer is a computer with a microprocessor as its central processing unit. They are physically small compared to mainframe and minicomputers...
in the late 1980s, and especially the introduction of powerful 32-bit systems in the 1990s, quickly eroded the value of DEC's systems. DEC's last major attempt to find a space in the rapidly changing market was the DEC Alpha
DEC Alpha
Alpha, originally known as Alpha AXP, is a 64-bit reduced instruction set computer instruction set architecture developed by Digital Equipment Corporation , designed to replace the 32-bit VAX complex instruction set computer ISA and its implementations. Alpha was implemented in microprocessors...
64-bit
64-bit
64-bit is a word size that defines certain classes of computer architecture, buses, memory and CPUs, and by extension the software that runs on them. 64-bit CPUs have existed in supercomputers since the 1970s and in RISC-based workstations and servers since the early 1990s...
RISC processor architecture. DEC initially started work on Alpha as a way to re-implement their VAX series, but also employed it in a range of high-performance workstations. Although the Alpha processor family met both of these goals, and, for most of its lifetime, was the fastest processor family on the market, it did little to affect the bottom line or repair the company's status.
The company was acquired in June 1998 by Compaq
Compaq
Compaq Computer Corporation is a personal computer company founded in 1982. Once the largest supplier of personal computing systems in the world, Compaq existed as an independent corporation until 2002, when it was acquired for US$25 billion by Hewlett-Packard....
, in what was at that time the largest merger in the history of the computer industry. At the time, Compaq 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. The company subsequently merged with Hewlett-Packard
Hewlett-Packard
Hewlett-Packard Company or HP is an American multinational information technology corporation headquartered in Palo Alto, California, USA that provides products, technologies, softwares, solutions and services to consumers, small- and medium-sized businesses and large enterprises, including...
in May 2002. some of DEC's product lines were still produced under the HP name.
Origins
Ken Olsen
Kenneth Harry Olsen was an American engineer who co-founded Digital Equipment Corporation in 1957 with colleague Harlan Anderson.-Background:...
and Harlan Anderson
Harlan Anderson
Harlan Anderson is an engineer and entrepreneur, best known as the co-founder of Digital Equipment Corporation which at one time was the second largest computer company in the world. Other notable entities he has been associated with include Lincoln Laboratory at the Massachusetts Institute of...
were two engineers who had been working at MIT Lincoln Laboratory
Lincoln Laboratory
MIT Lincoln Laboratory, located in Lexington, Massachusetts, is a United States Department of Defense research and development center chartered to apply advanced technology to problems of national security. Research and development activities focus on long-term technology development as well as...
on 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
Whirlwind (computer)
The Whirlwind computer was developed at the Massachusetts Institute of Technology. It is the first computer that operated in real time, used video displays for output, and the first that was not simply an electronic replacement of older mechanical systems...
which was originally developed to make a flight simulator
Flight simulator
A flight simulator is a device that artificially re-creates aircraft flight and various aspects of the flight environment. This includes the equations that govern how aircraft fly, how they react to applications of their controls and other aircraft systems, and how they react to the external...
for the US Navy, although this was never completed. Instead, this effort evolved into the SAGE
Semi Automatic Ground Environment
The Semi-Automatic Ground Environment was an automated control system for tracking and intercepting enemy bomber aircraft used by NORAD from the late 1950s into the 1980s...
system for the US Air Force, which used large screens and light gun
Light gun
A light gun is a pointing device for computers and a control device for arcade and video games.Modern screen-based light guns work by building a sensor into the gun itself, and the on-screen target emit light rather than the gun...
s to allow operators to interact with radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
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 transistor
Transistor
A transistor is a semiconductor device used to amplify and switch electronic signals and power. It is composed of a semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current...
s in place of vacuum tube
Vacuum tube
In electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...
s. In order to test their new circuitry, they first built a small 18-bit
18-bit
18 binary digits have unique combinations.-Example 18-bit computer architectures:* Possibly the most well-known 18-bit computer architectures are the PDP-1, PDP-4, PDP-7, PDP-9 and PDP-15 minicomputers produced by Digital Equipment Corporation from 1960 to 1975.* UNIVAC produced a number of...
machine known as TX-0
TX-0
The TX-0, for Transistorized Experimental computer zero, but affectionately referred to as tixo , was an early fully transistorized computer and contained a then-huge 64K of 18-bit words of magnetic core memory. The TX-0 was built in 1955 and went online in 1956 and was used continually through the...
which first ran in 1956. When the TX-0 successfully proved the basic concepts, attention turned to a much larger system, the 36-bit
36-bit word length
Many early computers aimed at the scientific market had a 36-bit word length. This word length was just long enough to represent positive and negative integers to an accuracy of ten decimal digits . It also allowed the storage of six alphanumeric characters encoded in a six-bit character encoding...
TX-2
TX-2
The MIT Lincoln Laboratory TX-2 computer was the successor to the Lincoln TX-0 and was known for its role in advancing both artificial intelligence and human-computer interaction.- Specifications :...
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, Olsen and Anderson noticed something odd: students would line up for hours to get a turn to use the stripped-down TX-0, while largely ignoring a faster IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
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 graphical output or realtime operation would be more important than outright performance. Additionally, as 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 wouldn't be needed.
In 1957 when the pair and Ken's brother Stan went looking for capital, they found that the American business community was hostile to investing in computer companies. Many smaller computer companies had come and gone in the 1950s, wiped out when new technical developments rendered their platforms obsolete, and even large companies like RCA
RCA
RCA Corporation, founded as the Radio Corporation of America, was an American electronics company in existence from 1919 to 1986. The RCA trademark is currently owned by the French conglomerate Technicolor SA through RCA Trademark Management S.A., a company owned by Technicolor...
and General Electric
General Electric
General Electric Company , or GE, is an American multinational conglomerate corporation incorporated in Schenectady, New York and headquartered in Fairfield, Connecticut, United States...
were failing to make a profit in the market. The only serious expression of interest came from Georges Doriot
Georges Doriot
Georges F. Doriot was one of the first American venture capitalists. In 1946, he founded American Research and Development Corporation, the first publicly owned venture capital firm...
and his American Research and Development Corporation
American Research and Development Corporation
American Research and Development Corporation was a venture capital and private equity firm founded in 1946 by Georges Doriot, the "father of venture capitalism" , with Ralph Flanders and Karl Compton .ARDC is credited with the first major venture capital success story when its 1957 investment of...
(AR&D). Worried that a new computer company would find it difficult to arrange further financing, Doriot suggested 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
Business plan
A business plan is a formal statement of a set of business goals, the reasons why they are believed attainable, and the plan for reaching those goals. It may also contain background information about the organization or team attempting to reach those goals....
that outlined two-phases for the company's development. They would start by selling computer module
Computer module
A computer module is a selection of independent electronic circuits packaged onto a circuit board to provide a basic function within a computer. An example might be an inverter or flip-flop, which would require two or more transistors and a small number of additional supporting devices...
s 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 a self-sustaining business, the company would be free to use them to develop a complete computer in their Phase II. The newly christened DEC received $70,000 from AR&D for a 70% share of the company, and began operations in a Civil War
American Civil War
The American Civil War was a civil war fought in the United States of America. In response to the election of Abraham Lincoln as President of the United States, 11 southern slave states declared their secession from the United States and formed the Confederate States of America ; the other 25...
era textile mill in Maynard, Massachusetts
Maynard, Massachusetts
Maynard is a town in Middlesex County, Massachusetts, United States. As of the 2010 census, the town population was 10,106.- History :Maynard, located on the Assabet River, was incorporated as an independent municipality in 1871. Prior to that it was known as 'Assabet Village' but was legally...
, where plenty of inexpensive manufacturing space was available.
Digital modules
The Laboratory Modules were packaged in an extruded aluminum housing, intended to sit on an engineer's workbench. They were then connected together using banana plug patch cords inserted at 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 in 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, turning a profit at the end of its first year.
The original Laboratory Modules were soon supplemented with the "Digital Systems 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 inserting them into a custom 19-inch rack
19-inch rack
A 19-inch rack is a standardized frame or enclosure for mounting multiple equipment modules. Each module has a front panel that is wide, including edges or ears that protrude on each side which allow the module to be fastened to the rack frame with screws.-Overview and history:Equipment designed...
. These versions allowed 25 modules be to inserted into a single 5-1/4 inch section of racking, and allowed the high densities needed to build a computer. DEC used the Systems 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.
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 the first "R" (red) series "Flip-Chip
Flip Chip (trademark)
Flip-Chip modules were used in the DEC PDP-7 , PDP-8, PDP-9 and PDP-10, beginning on August 24, 1964. The trademark "Flip-Chip"' was filed on August 27, 1964...
" modules. Later, other module series provided additional speed, much higher logic density, and industrial I/O capabilities. Digital published extensive data about the modules in free catalogs that became very popular.
PDP-1 family
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 the company's first computer, the PDP-1PDP-1
The PDP-1 was the first computer in Digital Equipment Corporation's PDP series and was first produced in 1960. It is famous for being the computer most important in the creation of hacker culture at MIT, BBN and elsewhere...
. 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 the next April. The PDP-1 sold in basic form for $120,000, or about $900,000 in 2011 US dollars. 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-bit
18-bit
18 binary digits have unique combinations.-Example 18-bit computer architectures:* Possibly the most well-known 18-bit computer architectures are the PDP-1, PDP-4, PDP-7, PDP-9 and PDP-15 minicomputers produced by Digital Equipment Corporation from 1960 to 1975.* UNIVAC produced a number of...
s 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 a single large mainframe case, with a hexagonal control panel containing switches and lights mounted to lay at table-top height at one end of the mainframe. Above the control panel was the system's standard input/output
Input/output
In computing, input/output, or I/O, refers to the communication between an information processing system , and the outside world, possibly a human, or another information processing system. Inputs are the signals or data received by the system, and outputs are the signals or data sent from it...
solution, a punch tape reader and writer. Most systems were purchased with two peripherals, the Type 30 vector graphics
Vector graphics
Vector graphics is the use of geometrical primitives such as points, lines, curves, and shapes or polygon, which are all based on mathematical expressions, to represent images in computer graphics...
display, and a Soroban Engineering modified IBM Model B Electric typewriter
IBM Electric typewriter
The IBM Electric typewriters were a series of electric typewriters that IBM manufactured, starting in the mid-1930s. They used the conventional moving carriage and typebar mechanism, as opposed to the fixed carriage and type ball used in the IBM Selectric, introduced in 1961...
that was used as a printer. The Soroban system was notoriously unreliable, and often replaced with a modified Friden Flexowriter
Friden Flexowriter
The Friden Flexowriter was a teleprinter, a heavy duty electric typewriter capable of being driven not only by a human typing, but also automatically by several methods including direct attachment to a computer and by use of paper tape....
, which also contained its own punch tape system. A variety of more-expensive add-ons followed, including magnetic tape
Magnetic tape
Magnetic tape is a medium for magnetic recording, made of a thin magnetizable coating on a long, narrow strip of plastic. It was developed in Germany, based on magnetic wire recording. Devices that record and play back audio and video using magnetic tape are tape recorders and video tape recorders...
systems, punched card
Punched card
A punched card, punch card, IBM card, or Hollerith card is a piece of stiff paper that contains digital information represented by the presence or absence of holes in predefined positions...
readers and punches, and faster punch tape and printer systems.
When DEC introduced the PDP-1, they also mentioned larger machines at 24, 30 and 36-bits, based on 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
Waltham, Massachusetts
Waltham is a city in Middlesex County, Massachusetts, United States, was an early center for the labor movement, and major contributor to the American Industrial Revolution. The original home of the Boston Manufacturing Company, the city was a prototype for 19th century industrial city planning,...
. According to the limited information available, they used it to process radar cross section data for the Lockheed A-12 reconnaissance aircraft
Reconnaissance aircraft
A reconnaissance aircraft is a manned military aircraft designed, or adapted, to carry out aerial reconnaissance.-History:The majority of World War I aircraft were reconnaissance designs...
. Gordon Bell
Gordon Bell
C. Gordon Bell is an American computer engineer and manager. An early employee of Digital Equipment Corporation 1960–1966, Bell designed several of their PDP machines and later became Vice President of Engineering 1972-1983, overseeing the development of the VAX...
remembered that it was being used in Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
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 the price. Like the PDP-1, about 54 PDP-4's were eventually sold, most to a customer base similar to the original PDP-1.
In 1964 DEC introduced its new Flip Chip
Flip Chip (trademark)
Flip-Chip modules were used in the DEC PDP-7 , PDP-8, PDP-9 and PDP-10, beginning on August 24, 1964. The trademark "Flip-Chip"' was filed on August 27, 1964...
module design, and used it to re-implement the PDP-4 as the PDP-7
PDP-7
The DEC PDP-7 is a minicomputer produced by Digital Equipment Corporation. Introduced in 1965, it was the first to use their Flip-Chip technology. With a cost of only $72,000 USD, it was cheap but powerful by the standards of the time. The PDP-7 was the third of Digital's 18-bit machines, with...
. 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 is most famous as the original machine for the Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
operating system.
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, 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
Floating point unit
A floating-point unit is a part of a computer system specially designed to carry out operations on floating point numbers. Typical operations are addition, subtraction, multiplication, division, and square root...
and a separate input/output
Input/output
In computing, input/output, or I/O, refers to the communication between an information processing system , and the outside world, possibly a human, or another information processing system. Inputs are the signals or data received by the system, and outputs are the signals or data sent from it...
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.
PDP-8 family
In 1962, Lincoln LaboratoryLincoln Laboratory
MIT Lincoln Laboratory, located in Lexington, Massachusetts, is a United States Department of Defense research and development center chartered to apply advanced technology to problems of national security. Research and development activities focus on long-term technology development as well as...
used 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
Input/output
In computing, input/output, or I/O, refers to the communication between an information processing system , and the outside world, possibly a human, or another information processing system. Inputs are the signals or data received by the system, and outputs are the signals or data sent from it...
(I/O) devices that made it easy to interface with various analog lab equipment. The LINC
LINC
The LINC was a 12-bit, 2048-word computer. The LINC can be considered the first minicomputer and a forerunner to the personal computer....
proved to attract intense interest in the scientific community, and has since been referred to as the first real minicomputer
Minicomputer
A minicomputer is a class of multi-user computers that lies in the middle range of the computing spectrum, in between the largest multi-user systems and the smallest single-user systems...
, a machine that was small and inexpensive enough to be dedicated to 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 11 August 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 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 22 March 1965, DEC introduced the PDP-8
PDP-8
The 12-bit PDP-8 was the first successful commercial minicomputer, produced by Digital Equipment Corporation in the 1960s. DEC introduced it on 22 March 1965, and sold more than 50,000 systems, the most of any computer up to that date. It was the first widely sold computer in the DEC PDP series of...
, 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 the CPU which allowed one to easily see the wire-wrapped internals of the CPU. Sold standard with 4 kWords of 12-bit core memory and a Teletype
Teletype Corporation
The Teletype Corporation, a part of American Telephone and Telegraph Company's Western Electric manufacturing arm since 1930, came into being in 1928 when the Morkrum-Kleinschmidt Company changed its name to the name of its trademark equipment...
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
Minicomputer
A minicomputer is a class of multi-user computers that lies in the middle range of the computing spectrum, in between the largest multi-user systems and the smallest single-user systems...
because of its sub-$25,000 price. Sales were, unsurprisingly, very strong, and helped by 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 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
LINC-8
LINC-8 was the name of a minicomputer manufactured by Digital Equipment Corporation between 1966 and 1969. It combined a LINC computer with a PDP-8 in one cabinet, thus being able to run programs written for either of the two architectures.-Architecture:...
. 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 the PDP-8, all in software. Although not a huge seller, 142 LINK-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 Digital and Intersil
Intersil
Intersil Corporation is an American company that specializes in the design, development and manufacturing of high-performance analog semiconductors for four high-growth markets — Communications, Computing, High End Consumer and Industrial.-Company history:...
, the Intersil 6100
Intersil 6100
The Intersil 6100 family consisted of a 12-bit microprocessor and a range of peripheral support and memory ICs developed in the mid-1970s.The microprocessor recognised the PDP-8 instruction set....
chip 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 Digital PDP-8 product line.
PDP-10 family
PDP-6
The PDP-6 was a computer model developed by Digital Equipment Corporation in 1963. It was influential primarily as the prototype for the later PDP-10; the instruction sets of the two machines are almost identical.The PDP-6 was DEC's first "big" machine...
was intended to take DEC into the mainframe
Mainframe computer
Mainframes are powerful computers used primarily by corporate and governmental organizations for critical applications, bulk data processing such as census, industry and consumer statistics, enterprise resource planning, and financial transaction processing.The term originally referred to the...
market with a 36-bit machine. However, the PDP-6 proved to be a "hard sell" with customers, as it offered few advantages over similar machines from the better established vendors like IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
or Honeywell
Honeywell
Honeywell International, Inc. is a major conglomerate company that produces a variety of consumer products, engineering services, and aerospace systems for a wide variety of customers, from private consumers to major corporations and governments....
, in spite of its low cost around $300,000. Only 23 were sold, or 26 depending on the source, and unlike earlier models the low sales meant the PDP-6 was not improved with intermediate versions. However, the PDP-6 is historically important as the platform that introduced "Monitor", an early time-sharing
Time-sharing
Time-sharing is the sharing of a computing resource among many users by means of multiprogramming and multi-tasking. Its introduction in the 1960s, and emergence as the prominent model of computing in the 1970s, represents a major technological shift in the history of computing.By allowing a large...
operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
that would evolve into the widely used TOPS-10
TOPS-10
The TOPS-10 System was a computer operating system from Digital Equipment Corporation for the PDP-10 mainframe computer launched in 1967...
.
In spite of the PDP-6's limited commercial success, it introduced many features that clearly had commercial benefit. When the Flip Chip packaging allowed the PDP-6 to be re-implemented at a much lower cost, DEC took the opportunity to carry out a similar evolution of their 36-bit design and introduced the PDP-10
PDP-10
The PDP-10 was a mainframe computer family manufactured by Digital Equipment Corporation from the late 1960s on; the name stands for "Programmed Data Processor model 10". The first model was delivered in 1966...
in 1968. The PDP-10 was as much a success as the PDP-6 was a failure; during its lifetime about 700 mainframe PDP-10s were sold before production ended in 1984. The PDP-10 was widely used in university settings, and thus 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, like "KA10". Later upgrades produced the compatible DECSYSTEM-20
DECSYSTEM-20
The DECSYSTEM-20 was a 36-bit Digital Equipment Corporation PDP-10 mainframe computer running the TOPS-20 operating system.PDP-10 computers running the TOPS-10 operating system were labeled DECsystem-10 as a way of differentiating them from the PDP-11...
, along with TOPS-20
TOPS-20
The TOPS-20 operating system by Digital Equipment Corporation was the second proprietary OS for the PDP-10 mainframe computer. TOPS-20 began in 1969 as the TENEX operating system of Bolt, Beranek and Newman...
that included virtual memory
Virtual memory
In computing, virtual memory is a memory management technique developed for multitasking kernels. This technique virtualizes a computer architecture's various forms of computer data storage , allowing a program to be designed as though there is only one kind of memory, "virtual" memory, which...
.
DECtape
One of the most unusual peripherals produced for the PDP-10 was the DECtapeDECtape
DECtape, originally called "Microtape", was a magnetic tape data storage medium used with many Digital Equipment Corporation computers, including the PDP-6, PDP-8, LINC-8, PDP-10, PDP-11, PDP-12, and the PDP-15. On DEC's 32-bit systems, VAX/VMS support for it was implemented but did not become an...
. The DECtape was a length of special 3/4-inch wide magnetic tape wound on 5-inch reels. The recording format was a 10-track approach using fixed-length numbered 'blocks' organized into a standard file structure, including a directory. Files could be written, read, changed, and deleted on a DECtape as though it were a disk drive. For greater efficiency, the DECtape drive could read and write to a DECtape in both directions.
In fact, some PDP-10 systems had no disks at all, using DECtapes alone for their primary data storage. The DECtape was also widely used on other PDP models, since it was much easier to use than hand-loading multiple paper tapes. Primitive early time-sharing systems could use DECtapes as system devices and swapping devices. Although superior to paper tape, DECtapes were relatively slow, and were supplanted as reliable disk drives became affordable.
PDP-11
In 1968, DEC was developing a PDP machine that would be based on 8-bit byteByte
The byte is a unit of digital information in computing and telecommunications that most commonly consists of eight bits. Historically, a byte was the number of bits used to encode a single character of text in a computer and for this reason it is the basic addressable element in many computer...
s instead of 6-bit characters. Known as the "PDP-X", the project was eventually cancelled. Several team members decamped and set up Data General
Data General
Data General was one of the first minicomputer firms from the late 1960s. Three of the four founders were former employees of Digital Equipment Corporation. Their first product, the Data General Nova, was a 16-bit minicomputer...
in May 1968, and rapidly brought the 16-bit NOVA
Data General Nova
The Data General Nova was a popular 16-bit minicomputer built by the American company Data General starting in 1969. The Nova was packaged into a single rack mount case and had enough power to do most simple computing tasks. The Nova became popular in science laboratories around the world, and...
minicomputer to market. DEC immediately found itself behind in the industry transition to 8-bit bytes, and soon lost its crown as the largest minicomputer vendor.
The PDP-11
PDP-11
The PDP-11 was a series of 16-bit minicomputers sold by Digital Equipment Corporation from 1970 into the 1990s, one of a succession of products in the PDP series. The PDP-11 replaced the PDP-8 in many real-time applications, although both product lines lived in parallel for more than 10 years...
16-bit computer was designed in a crash program by Harold McFarland, Gordon Bell
Gordon Bell
C. Gordon Bell is an American computer engineer and manager. An early employee of Digital Equipment Corporation 1960–1966, Bell designed several of their PDP machines and later became Vice President of Engineering 1972-1983, overseeing the development of the VAX...
, 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
Carnegie Mellon University
Carnegie Mellon University is a private research university in Pittsburgh, Pennsylvania, United States....
. One of his simpler designs became the PDP-11, although when they first viewed the proposal, management was not impressed and almost cancelled it.
In particular, the new design did not include many of the addressing mode
Addressing mode
Addressing modes are an aspect of the instruction set architecture in most central processing unit designs. The various addressing modes that are defined in a given instruction set architecture define how machine language instructions in that architecture identify the operand of each instruction...
s 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 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 Digital's Unibus
Unibus
The Unibus was the earliest of several computer bus technologies used with PDP-11 and early VAX systems manufactured by the Digital Equipment Corporation of Maynard, Massachusetts.-History:...
, which supported all peripherals through memory mapping
Memory mapping
In computing, memory mapping may refer to:* Memory-mapped file, also known as mmap* Memory-mapped I/O, an alternative to port I/O; a communication between CPU and peripheral device using the same instructions, and same bus, as between CPU and memory...
. This allowed a new device to be added easily, generally only requiring plugging a hardware interface board into the 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 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
Paging
In computer operating systems, paging is one of the memory-management schemes by which a computer can store and retrieve data from secondary storage for use in main memory. In the paging memory-management scheme, the operating system retrieves data from secondary storage in same-size blocks called...
and memory protection
Memory protection
Memory protection is a way to control memory access rights on a computer, and is a part of most modern operating systems. The main purpose of memory protection is to prevent a process from accessing memory that has not been allocated to it. This prevents a bug within a process from affecting...
features, useful for multitasking
Computer multitasking
In computing, multitasking is a method where multiple tasks, also known as processes, share common processing resources such as a CPU. In the case of a computer with a single CPU, only one task is said to be running at any point in time, meaning that the CPU is actively executing instructions for...
and time-sharing
Time-sharing
Time-sharing is the sharing of a computing resource among many users by means of multiprogramming and multi-tasking. Its introduction in the 1960s, and emergence as the prominent model of computing in the 1970s, represents a major technological shift in the history of computing.By allowing a large...
. 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'
Bell Labs
Bell Laboratories is the research and development subsidiary of the French-owned Alcatel-Lucent and previously of the American Telephone & Telegraph Company , half-owned through its Western Electric manufacturing subsidiary.Bell Laboratories operates its...
new Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
operating system as well as DEC's DOS-11, RSX-11
RSX-11
RSX-11 is a family of real-time operating systems mainly for PDP-11 computers created by Digital Equipment Corporation , common in the late 1970s and early 1980s. RSX-11D first appeared on the PDP-11/40 in 1972...
, IAS, RT-11
RT-11
RT-11 was a small, single-user real-time operating system for the Digital Equipment Corporation PDP-11 family of 16-bit computers...
, DSM-11, and RSTS/E
RSTS/E
RSTS is a multi-user time-sharing operating system, developed by Digital Equipment Corporation , for the PDP-11 series of 16-bit minicomputers. The first version of RSTS was implemented in 1970 by DEC software engineers that developed the TSS-8 time-sharing operating system for the PDP-8...
. Many early PDP-11 applications were developed using standalone paper-tape utilities. DOS-11 was the PDP-11's first disk operating system, but was soon supplanted by more capable systems. RSX provided a general-purpose multitasking
Computer multitasking
In computing, multitasking is a method where multiple tasks, also known as processes, share common processing resources such as a CPU. In the case of a computer with a single CPU, only one task is said to be running at any point in time, meaning that the CPU is actively executing instructions for...
environment and supported a wide variety of programming language
Programming language
A programming language is an artificial language designed to communicate instructions to a machine, particularly a computer. Programming languages can be used to create programs that control the behavior of a machine and/or to express algorithms precisely....
s. IAS was a time-sharing
Time-sharing
Time-sharing is the sharing of a computing resource among many users by means of multiprogramming and multi-tasking. Its introduction in the 1960s, and emergence as the prominent model of computing in the 1970s, represents a major technological shift in the history of computing.By allowing a large...
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 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
AT&T
AT&T Inc. is an American multinational telecommunications corporation headquartered in Whitacre Tower, Dallas, Texas, United States. It is the largest provider of mobile telephony and fixed telephony in the United States, and is also a provider of broadband and subscription television services...
became DEC's largest customer.
RT-11 provided a practical real-time operating system in minimal memory, allowing the PDP-11 to continue Digital's critical role as a computer supplier for embedded system
Embedded system
An embedded system is a computer system designed for specific control functions within a larger system. often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal...
s. Historically, RT-11 also served as 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
CP/M
CP/M was a mass-market operating system created for Intel 8080/85 based microcomputers by Gary Kildall of Digital Research, Inc...
used a command syntax similar to RT-11's, and even retained the awkward PIP
Peripheral Interchange Program
Peripheral Interchange Program was a utility to transfer files on and between devices on Digital Equipment Corporation's computers. It was first implemented on the PDP-6 architecture by Harrison "Dit" Morse early in the 1960s...
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 the adoption of "\" for pathnames in MS-DOS
MS-DOS
MS-DOS is an operating system for x86-based personal computers. It was the most commonly used member of the DOS family of operating systems, and was the main operating system for IBM PC compatible personal computers during the 1980s to the mid 1990s, until it was gradually superseded by operating...
and Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
as opposed to "/" in Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
.
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-11's of all models were sold. and a wide variety of third-party peripheral vendors had also entered the computer product ecosystem.
Many PDP-11-like machines were also introduced by competitors. The PDP-11 series was cloned in COMECON countries as the SM EVM
SM EVM
SM EVM was the general name for several types of Soviet and Comecon minicomputers produced in the 1970s and 1980s. Production began in 1975....
series, and was produced in quantities comparable to original PDP-11 production.
VAX
In 1976, DEC decided to extend the PDP-11PDP-11
The PDP-11 was a series of 16-bit minicomputers sold by Digital Equipment Corporation from 1970 into the 1990s, one of a succession of products in the PDP series. The PDP-11 replaced the PDP-8 in many real-time applications, although both product lines lived in parallel for more than 10 years...
architecture to 32-bit
32-bit
The range of integer values that can be stored in 32 bits is 0 through 4,294,967,295. Hence, a processor with 32-bit memory addresses can directly access 4 GB of byte-addressable memory....
s while adding a complete virtual memory
Virtual memory
In computing, virtual memory is a memory management technique developed for multitasking kernels. This technique virtualizes a computer architecture's various forms of computer data storage , allowing a program to be designed as though there is only one kind of memory, "virtual" memory, which...
system to the simple paging and memory protection of the PDP-11. The result was the VAX
VAX
VAX was an instruction set architecture developed by Digital Equipment Corporation in the mid-1970s. A 32-bit complex instruction set computer ISA, it was designed to extend or replace DEC's various Programmed Data Processor ISAs...
architecture. The first computer to use a VAX CPU was the VAX-11/780, 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
Jupiter project
The Jupiter project was to be a successor to Digital Equipment Corporation 's PDP-10 model. This project was cancelled in 1983, as the PDP-10 was increasingly eclipsed by the VAX supermini machines...
, which had been intended to build a successor to the PDP-10 mainframe, and instead focused on promoting the VAX as their the single computer architecture for the company.
Supporting the VAX's success was the VT52
VT52
The VT52 was a CRT-based computer terminal produced by Digital Equipment Corporation introduced in September, 1975 . It provided a screen of 24 rows and 80 columns of text and supported all 95 ASCII characters as well as 32 graphics characters. It supported asynchronous communication at baud rates...
, one of the most successful smart terminal
Smart terminal
In computing, smart terminal can mean either:* A thin client with local data processing capacity* A computer terminal that has capabilities for cursor positioning, or other display formatting capabilities beyond a text-mode teleprinter...
s. Building on earlier less successful models (the VT05
VT05
The VT05 was the first free-standing CRT computer terminal from Digital Equipment Corporation. Famous for its extremely futuristic styling, the VT05 presented the user with an upper-case only 5x7 dot-matrix display of 20 rows by 72 columns. The terminal only supported forward scrolling and direct...
and VT50), the VT52 was the first terminal that did everything one might want in a single chassis. The VT52 was followed by the even more successful VT100
VT100
The VT100 is a video terminal that was made by Digital Equipment Corporation . Its detailed attributes became the de facto standard for terminal emulators.-History:...
and its follow-ons, making DEC one of the largest terminal vendors in the industry. With the VT 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 the 1980s, culminating in the NVAX
NVAX
The NVAX is a microprocessor developed and fabricated by Digital Equipment Corporation that implemented the VAX instruction set architecture . The NVAX was a high-end single-chip VAX microprocessor. A variant of the NVAX, the NVAX+, differed in the bus interface and external cache supported, but...
microprocessor
Microprocessor
A microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...
implementation and VAX 7000/10000
VAX 7000/10000
The VAX 7000 and VAX 10000 were a series of high-end multiprocessor minicomputers developed and manufactured by Digital Equipment Corporation , introduced in July 1992. These systems used microprocessors implementing the VAX instruction set architecture...
series in the early 1990s.
Early microcomputers
The introduction of the first general purpose microprocessorMicroprocessor
A microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...
s inevitably led to the first microcomputers around 1975. At the time these systems were of limited utility, and Ken Olsen famously derided them in 1977, stating "There 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. At the beginning of the 1980s, DEC built the VT180
VT180
The VT180 was a video terminal produced by Digital Equipment Corporation of Maynard, Massachusetts.An extension of their existing line of VT100 terminals, this version integrated a Z80 microprocessor and two external 5.25-inch floppy disk drives...
(codenamed "Robin"), which was a VT100
VT100
The VT100 is a video terminal that was made by Digital Equipment Corporation . Its detailed attributes became the de facto standard for terminal emulators.-History:...
terminal with an added Z80
Zilog Z80
The Zilog Z80 is an 8-bit microprocessor designed by Zilog and sold from July 1976 onwards. It was widely used both in desktop and embedded computer designs as well as for military purposes...
-based microcomputer running CP/M
CP/M
CP/M was a mass-market operating system created for Intel 8080/85 based microcomputers by Gary Kildall of Digital Research, Inc...
, but this product was initially available only to DEC employees.
It was only after IBM had successfully launched the IBM PC
IBM PC
The IBM Personal Computer, commonly known as the IBM PC, is the original version and progenitor of the IBM PC compatible hardware platform. It is IBM model number 5150, and was introduced on August 12, 1981...
in 1981 that DEC responded with their own systems. In 1982, Digital introduced not one, but three incompatible machines which were each tied to different proprietary
Proprietary hardware
Proprietary hardware is computer hardware which is owned by the proprietor.Historically, most early computer hardware was designed as proprietary until the 1980s, when IBM PC changed this paradigm...
architectures. The first, the DEC Professional
DEC Professional (computer)
The Professional 325 and Professional 350 were PDP-11 compatible microcomputers introduced in 1982 by Digital Equipment Corporation as high-end competitors to the IBM PC...
, was based on the PDP-11/23 (and later, the 11/73) running the RSX-11M+
RSX-11
RSX-11 is a family of real-time operating systems mainly for PDP-11 computers created by Digital Equipment Corporation , common in the late 1970s and early 1980s. RSX-11D first appeared on the PDP-11/40 in 1972...
derived, but menu-driven, P/OS ("Professional Operating System"). This DEC machine easily outperformed the PC, but was more expensive than, and completely incompatible with IBM PC hardware and software, offering far fewer options for customizing a system. 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
PC-DOS
IBM PC DOS is a DOS system for the IBM Personal Computer and compatibles, manufactured and sold by IBM from the 1980s to the 2000s....
or CP/M
CP/M
CP/M was a mass-market operating system created for Intel 8080/85 based microcomputers by Gary Kildall of Digital Research, Inc...
, which were more commonly used on the 8080 and 8088 based microcomputers of the time. A second offering, the DECmate II
DECmate
DECmate was the name of a series of PDP-8-compatible computers produced by the Digital Equipment Corporation in the late 1970s and early 1980s. All of the models used an Intersil 6100 or Harris 6120 microprocessor which emulated the 12-bit DEC PDP-8 CPU...
was the latest version of the PDP-8 based word processors, but not really suited to general computing, nor competitive with Wang Laboratories
Wang Laboratories
Wang Laboratories was a computer company founded in 1951 by Dr. An Wang and Dr. G. Y. Chu. The company was successively headquartered in Cambridge , Tewksbury , and finally in Lowell, Massachusetts . At its peak in the 1980s, Wang Laboratories had annual revenues of $3 billion and employed over...
' popular word processing equipment.
The best known of DEC's early microcomputers was the Rainbow 100
Rainbow 100
The Rainbow 100 was a microcomputer introduced by Digital Equipment Corporation in 1982. This desktop unit had the video-terminal display circuitry from the VT102, a video monitor similar to the VT220 in a dual-CPU box with both Zilog Z80 and Intel 8088 CPUs.The Rainbow 100 was a triple-use...
, which ran an implementation of CP/M
CP/M-86
CP/M-86 was a version of the CP/M operating system that Digital Research made for the Intel 8086 and Intel 8088. The commands are those of CP/M-80. Executable files used the relocatable .CMD file format...
on the Intel 8086
Intel 8086
The 8086 is a 16-bit microprocessor chip designed by Intel between early 1976 and mid-1978, when it was released. The 8086 gave rise to the x86 architecture of Intel's future processors...
processor. 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
Lotus 1-2-3
Lotus 1-2-3 is a spreadsheet program from Lotus Software . It was the IBM PC's first "killer application"; its huge popularity in the mid-1980s contributed significantly to the success of the IBM PC in the corporate environment.-Beginnings:...
, which was eventually ported along with MS-DOS
MS-DOS
MS-DOS is an operating system for x86-based personal computers. It was the most commonly used member of the DOS family of operating systems, and was the main operating system for IBM PC compatible personal computers during the 1980s to the mid 1990s, until it was gradually superseded by operating...
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.
The way the DEC standard RX50 floppy disk drive supported DEC's initial offerings seemed to encapsulate their approach to the personal computer market. Although the mechanical drive hardware was nearly identical to other 5.25" floppy disk drives available on competing systems, DEC sought to differentiate their product by using a proprietary disk format for the data written on the disk. The DEC format had a higher capacity for data, but the RX50 drives were incompatible with other PC floppy drives. This required DEC owners to buy higher-priced, specially-formatted floppy media, which was harder to obtain through standard distribution channels. DEC attempted to enforce exclusive control over its floppy media sales by copyright
Copyright
Copyright is a legal concept, enacted by most governments, giving the creator of an original work exclusive rights to it, usually for a limited time...
ing its proprietary disk format, and requiring a negotiated license agreement and royalty payments from anybody selling compatible media. The proprietary data format meant that RX50 floppies were not interchangeable with other PC floppies, further isolating DEC products from the developing de facto standard PC market. Hardware hackers and DEC enthusiasts eventually reverse-engineered the RX50 format, but the damage had already been done, in terms of market confusion and isolation.
A further system was introduced in 1986 as the VAXmate
VAXmate
VAXmate was an IBM PC/AT compatible personal computer introduced by Digital Equipment Corporation in September, 1986. The replacement to the Rainbow 100, in its standard form it was the first commercial diskless personal computer.-OS and files:...
, which included Microsoft Windows 1.0 and used VAX/VMS-based file and print servers along with integration into DEC's own DECnet
DECnet
DECnet is a suite of network protocols created by Digital Equipment Corporation, originally released in 1975 in order to connect two PDP-11 minicomputers. It evolved into one of the first peer-to-peer network architectures, thus transforming DEC into a networking powerhouse in the 1980s...
-family, providing LAN/WAN connection from PC to mainframe or supermini. The VAXmate replaced the Rainbow, and in its standard form was the first widely marketed diskless workstation.
Networking and clusters
In 1984, DEC launched its first 10 Mbit/s EthernetEthernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....
. Ethernet allowed scalable networking, and VAXcluster allowed scalable computing. Combined with DECnet
DECnet
DECnet is a suite of network protocols created by Digital Equipment Corporation, originally released in 1975 in order to connect two PDP-11 minicomputers. It evolved into one of the first peer-to-peer network architectures, thus transforming DEC into a networking powerhouse in the 1980s...
and Ethernet-based terminal servers (LAT
Local Area Transport
Local Area Transport is a non-routable networking technology developed by Digital Equipment Corporation to provide connection between the DECserver 90, 100, 200, 300, 500, 700 and DECserver 900 terminal servers and Digital's VAX and Alpha and MIPS_architecture host computers via Ethernet, giving...
), DEC had produced a networked storage architecture which allowed them to compete directly with IBM. Ethernet replaced token ring, and went on to become the dominant networking model in use today.
In September 1985, DEC became the fifth company to register a .com
.com
The domain name com is a generic top-level domain in the Domain Name System of the Internet. Its name is derived from commercial, indicating its original intended purpose for domains registered by commercial organizations...
domain name
Domain name
A domain name is an identification string that defines a realm of administrative autonomy, authority, or control in the Internet. Domain names are formed by the rules and procedures of the Domain Name System ....
(dec.com).
Along with the hardware and protocols, DEC also introduced the VAXcluster concept, which allowed several VAX machines to be tied together into a single larger storage system. VAXclusters allowed a DEC-based company to scale their services by adding new machines to the cluster at any time, as opposed to buying a faster machine and using that to replace a slower one. The flexibility this offered was compelling, and allowed DEC to attack high-end markets formerly out of their reach.
Diversification
Although their microcomputer efforts were eventually considered failures, the PDP-11 and VAX lines continued to sell in record numbers. Better yet, DEC was competing very well against the market leader, IBM, taking an estimated $2 billion away from them in the mid-80s. In 1986, Digital's profits rose 38 percent when the rest of the computer industry experienced a downturn, and by 1987 the company was threatening IBM's number one position in the computer industry.At its peak, Digital was the second-largest computer company in the world, with over 100,000 employees. It was during this time that the company branched out development into a wide variety of projects that were far from its core business in computer equipment. The company invested heavily in custom software. In the 1970s and earlier most software was custom-written to serve a specific task, but by the 1980s the introduction of relational databases and similar systems allowed powerful software to be built in a modular fashion, potentially saving enormous amounts of development time. Software companies like Oracle
Oracle Corporation
Oracle Corporation is an American multinational computer technology corporation that specializes in developing and marketing hardware systems and enterprise software products – particularly database management systems...
became the new darlings of the industry, and DEC started their own efforts in every "hot" niche, in some cases several projects for the same niche. Some of these products competed with DEC's own partners, notably Rdb
RDB
Rdb and RDB can refer to:* Rang de Basanti, a 2006 Hindi-language film starring Aamir Khan, Soha Ali Khan, R. Madhavan, Siddharth Narayan, Sharman Joshi, Kunal Kapoor and Alice Patten...
which competed with Oracle's products on the VAX, part of a major partnership only a few years earlier.
Although many of these products were well designed, most of them were DEC-only or DEC-centric, and customers frequently ignored them and used third-party products instead. This problem was further exacerbated by Olsen's aversion to traditional advertising and his belief that well-engineered products would sell themselves. Hundreds of millions of dollars were spent on these projects, at the same time that workstations using RISC microprocessors were starting to approach VAX CPUs in performance.
Faltering in the market
As microprocessors continued to improve in the 1980s, it soon became clear that the next generation would offer performance and features equal to the best of DECs low-end minicomputer lineup. Worse, the Berkeley RISCBerkeley RISC
Berkeley RISC was one of two seminal research projects into RISC-based microprocessor design taking place under ARPA's VLSI project. RISC was led by David Patterson at the University of California, Berkeley between 1980 and 1984, while the other was taking place only a short drive away at Stanford...
and Stanford MIPS
MIPS architecture
MIPS is a reduced instruction set computer instruction set architecture developed by MIPS Technologies . The early MIPS architectures were 32-bit, and later versions were 64-bit...
designs were aiming to introduce 32-bit designs that would outperform the fastest members of the VAX family, DEC's cash cow
Cash cow
In business, a cash cow is a product or a business unit that generates unusually high profit margins: so high that it is responsible for a large amount of a company's operating profit...
.
Constrained by the huge success of their VAX
VAX
VAX was an instruction set architecture developed by Digital Equipment Corporation in the mid-1970s. A 32-bit complex instruction set computer ISA, it was designed to extend or replace DEC's various Programmed Data Processor ISAs...
/VMS
OpenVMS
OpenVMS , previously known as VAX-11/VMS, VAX/VMS or VMS, is a computer server operating system that runs on VAX, Alpha and Itanium-based families of computers. Contrary to what its name suggests, OpenVMS is not open source software; however, the source listings are available for purchase...
products, which followed the proprietary model, the company was very late to respond to these threats. In the early 1990s, DEC found its sales faltering and its first layoffs followed. The company that created the minicomputer, a dominant networking technology, and arguably the first computers for personal use, had abandoned the "low end" market, whose dominance with the PDP-8 had built the company in a previous generation. Decisions about what to do about this threat led to infighting within the company that seriously delayed their responses.
One group suggested that every possible development in the industry be poured into the construction of a new VAX family that would leapfrog the performance of the existing machines. This would limit the market erosion in the top-end segment, where profit margin
Profit margin
Profit margin, net margin, net profit margin or net profit ratio all refer to a measure of profitability. It is calculated by finding the net profit as a percentage of the revenue.Net profit Margin = x100...
s were maximized and DEC could continue to survive as a minicomputer vendor. This line of thought led, eventually, to the VAX 9000
VAX 9000
The VAX 9000, code named Aridus, was a family of high-end minicomputers developed and manufactured by Digital Equipment Corporation using processors implementing the VAX instruction set architecture . The VAX 9000 was positioned by Digital as its first mainframe...
series, which were plagued with problems when they were first introduced in October 1989, already two years late. The problems took so long to work out, and the prices of the systems were so high, that DEC was never able to make the line the success they hoped.
Others within the company felt that the proper response was to introduce their own RISC designs and use those to build new machines. However, there was little official support for these efforts, and no less than four separate small projects ran in parallel at various labs around the US. Eventually these were gathered into the DEC PRISM
DEC PRISM
PRISM was a 32-bit RISC instruction set architecture developed by Digital Equipment Corporation . It was the final outcome of a number of DEC research projects from the 1982–1985 time-frame, and was at the point of delivering silicon in 1988 when the management canceled the project...
project, which delivered a credible 32-bit design with some unique features allowing it to serve as the basis of a new VAX implementation. Infighting with teams dedicated to DEC's big iron made funding difficult, and the design was not finalized until April 1988, and then cancelled shortly thereafter.
Another group concluded that new workstation
Workstation
A workstation is a high-end microcomputer designed for technical or scientific applications. Intended primarily to be used by one person at a time, they are commonly connected to a local area network and run multi-user operating systems...
s like those from Sun Microsystems
Sun Microsystems
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
and Silicon Graphics
Silicon Graphics
Silicon Graphics, Inc. was a manufacturer of high-performance computing solutions, including computer hardware and software, founded in 1981 by Jim Clark...
would take away a large part of DEC's existing customer base before the new VAX systems could address the issues, and that the company needed its own Unix workstation as soon as possible. Fed up with slow progress on both the RISC and VAX fronts, a group in Palo Alto
Palo Alto, California
Palo Alto is a California charter city located in the northwest corner of Santa Clara County, in the San Francisco Bay Area of California, United States. The city shares its borders with East Palo Alto, Mountain View, Los Altos, Los Altos Hills, Stanford, Portola Valley, and Menlo Park. It is...
started a skunkworks project
Skunkworks project
A skunkworks project is one typically developed by a small and loosely structured group of people who research and develop a project primarily for the sake of radical innovation. The term typically refers to technology projects, and originated with Skunk Works, an official alias for the Lockheed...
to introduce their own systems. Selecting the MIPS processor, which was widely available, introducing the new DECstation
DECstation
The DECstation was a brand of computers used by DEC, and refers to three distinct lines of computer systems—the first released in 1978 as a word processing system, and the latter two both released in 1989. These comprised a range of computer workstations based on the MIPS architecture and a...
series with the model 3100 on 11 January 1989. These systems would see some success in the market, but were later displaced by similar models running the Alpha.
32-bit MIPS and 64-bit Alpha systems
Eventually, in 1992, DEC launched the DECchip 21064Alpha 21064
The Alpha 21064 is a microprocessor developed and fabricated by Digital Equipment Corporation that implemented the Alpha instruction set architecture . It was introduced as the DECchip 21064 before it was renamed in 1994. The 21064 is also known by its code name, EV4...
processor, the first implementation of their Alpha
DEC Alpha
Alpha, originally known as Alpha AXP, is a 64-bit reduced instruction set computer instruction set architecture developed by Digital Equipment Corporation , designed to replace the 32-bit VAX complex instruction set computer ISA and its implementations. Alpha was implemented in microprocessors...
instruction set architecture, initially named Alpha AXP (the "AXP" was a "non-acronym" and was later dropped). This was a 64-bit
64-bit
64-bit is a word size that defines certain classes of computer architecture, buses, memory and CPUs, and by extension the software that runs on them. 64-bit CPUs have existed in supercomputers since the 1970s and in RISC-based workstations and servers since the early 1990s...
RISC architecture (as opposed to the 32-bit CISC
Complex instruction set computer
A complex instruction set computer , is a computer where single instructions can execute several low-level operations and/or are capable of multi-step operations or addressing modes within single instructions...
architecture used in the VAX) and one of the first "pure" (not an extension of an earlier 32-bit architecture) 64-bit microprocessor
Microprocessor
A microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...
architectures and implementations. The Alpha offered class-leading performance at its launch, and subsequent variants continued to do so into the 2000s. An AlphaServer SC45 supercomputer was still ranked No. 6 in the world in November 2004. Alpha-based computers (the DEC AXP series, later the AlphaStation
AlphaStation
AlphaStation was the name given to a series of computer workstations, produced from 1994 onwards by Digital Equipment Corporation, and latterly by Compaq and HP. As the name suggests, the AlphaStations were based on the DEC Alpha 64-bit microprocessor...
and AlphaServer
AlphaServer
AlphaServer was the name given to a series of server computers, produced from 1994 onwards by Digital Equipment Corporation, and latterly by Compaq and HP. As the name suggests, the AlphaServers were based on the DEC Alpha 64-bit microprocessor...
series) superseded both the VAX and MIPS architecture in DEC's product lines, and could run OpenVMS
OpenVMS
OpenVMS , previously known as VAX-11/VMS, VAX/VMS or VMS, is a computer server operating system that runs on VAX, Alpha and Itanium-based families of computers. Contrary to what its name suggests, OpenVMS is not open source software; however, the source listings are available for purchase...
, DEC OSF/1 AXP (later, Digital Unix or Tru64 UNIX) and Microsoft's then-new operating system, Windows NT
Windows NT
Windows NT is a family of operating systems produced by Microsoft, the first version of which was released in July 1993. It was a powerful high-level-language-based, processor-independent, multiprocessing, multiuser operating system with features comparable to Unix. It was intended to complement...
.
In 1998, following the takeover by Compaq Computers, a decision was made that Microsoft would no longer support and develop Windows NT for the Alpha series computers, a decision that was seen as the beginning of the end for the Alpha series computers.
DEC tried to compete in the Unix market by adding POSIX
POSIX
POSIX , an acronym for "Portable Operating System Interface", is a family of standards specified by the IEEE for maintaining compatibility between operating systems...
-compatibility features to the VAX/VMS operating system (becoming "OpenVMS") and by selling its own version of Unix (Ultrix
Ultrix
Ultrix was the brand name of Digital Equipment Corporation's native Unix systems. While ultrix is the Latin word for avenger, the name was chosen solely for its sound.-History:...
on PDP-11, VAX and MIPS architectures; OSF/1 on Alpha), and began to advertise more aggressively. DEC was simply not prepared to sell into a crowded Unix market however, and the low end PC-servers running NT (based on Intel processors) took market share from Alpha-based computers. DEC's workstation and server line never gained much popularity beyond former DEC customers.
StrongARM
In the mid-1990s, Digital Semiconductor collaborated with ARM Limited to produce the StrongARMStrongARM
The StrongARM is a family of microprocessors that implemented the ARM V4 instruction set architecture . It was developed by Digital Equipment Corporation and later sold to Intel, who continued to manufacture it before replacing it with the XScale....
microprocessor. This was based in part on ARM7 and in part on DEC technologies like Alpha, and was targeted at embedded system
Embedded system
An embedded system is a computer system designed for specific control functions within a larger system. often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal...
s and portable devices. It was highly compatible with the ARMv4 architecture and was very successful, competing effectively against rivals such as the SuperH
SuperH
SuperH is a 32-bit reduced instruction set computer instruction set architecture developed by Hitachi. It is implemented by microcontrollers and microprocessors for embedded systems....
and MIPS architecture
MIPS architecture
MIPS is a reduced instruction set computer instruction set architecture developed by MIPS Technologies . The early MIPS architectures were 32-bit, and later versions were 64-bit...
s in the portable digital assistant market. Microsoft
Microsoft
Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...
subsequently dropped support for these other architectures in their Pocket PC
Pocket PC
A Pocket PC is also known by Microsoft as a 'Windows Mobile Classic device'. It is a hardware specification for a handheld-sized computer, personal digital assistant , that runs the Microsoft 'Windows Mobile Classic' operating system...
platform. In 1997, as part of a lawsuit settlement, the StrongARM
StrongARM
The StrongARM is a family of microprocessors that implemented the ARM V4 instruction set architecture . It was developed by Digital Equipment Corporation and later sold to Intel, who continued to manufacture it before replacing it with the XScale....
intellectual property was sold to Intel. They continued to produce StrongARM
StrongARM
The StrongARM is a family of microprocessors that implemented the ARM V4 instruction set architecture . It was developed by Digital Equipment Corporation and later sold to Intel, who continued to manufacture it before replacing it with the XScale....
, as well as developing it into the XScale
XScale
The XScale, a microprocessor core, is Intel's and Marvell's implementation of the ARMv5 architecture, and consists of several distinct families: IXP, IXC, IOP, PXA and CE . Intel sold the PXA family to Marvell Technology Group in June 2006....
architecture. Intel subsequently sold this business to Marvell Technology Group
Marvell Technology Group
Marvell is an American producer of storage, communications and consumer semiconductor products.Founded in 1995, Marvell Technology Group Ltd. has operations worldwide and approximately 5,700 employees. Marvell’s U.S. operating subsidiary is based in Santa Clara, California and Marvell has...
in 2006.
Designing solutions
Beyond DECsystem-10/20, PDP, VAX and Alpha, Digital was well respected for its communication subsystem designs, such as Ethernet, DNA (Digital Network Architecture – predominantly DECnet products), DSA (Digital Storage Architecture – disks/tapes/controllers), and its "dumb terminal" subsystems including VT100 and DECserver products.Final years
In June 1992, Ken OlsenKen Olsen
Kenneth Harry Olsen was an American engineer who co-founded Digital Equipment Corporation in 1957 with colleague Harlan Anderson.-Background:...
was replaced by Robert Palmer
Robert Palmer (computer businessman)
Robert B. Palmer is an American businessman best known for his role as the last Chairman and Chief Executive Officer of Digital Equipment Corporation....
as the company's president. Digital's board of directors also granted Palmer the title of chief executive officer ("CEO"), a title that had never been used during Digital's 35-year existence. Palmer had joined DEC in 1985 to run Semiconductor Engineering and Manufacturing. His relentless campaign to be CEO, and success with the Alpha microprocessor family, made him a candidate to succeed Olsen. At the same time a more modern logo was designed
During the profitable years up until the early 1990s, DEC was a company that boasted that it never had a general layoff; following the 1992 economic downturn, layoffs became regular events as the company continually downsized to try to stay afloat. Palmer was tasked with the goal of bringing DEC back to profitability, which he attempted to do by changing the established DEC business culture, hiring new executives from outside the company, and selling off various non-core business units:
- Worldwide training was spun off to form an independent/new company called Global Knowledge Network.
- RdbOracle RdbRdb/VMS is a relational database management system for the Hewlett-Packard OpenVMS operating system. It was originally created by Digital Equipment Corporation in 1984 as part of the VMS Information Architecture, intended to be used for data storage and retrieval by high-level languages and/or...
, DEC's database product, was sold to OracleOracle CorporationOracle Corporation is an American multinational computer technology corporation that specializes in developing and marketing hardware systems and enterprise software products – particularly database management systems...
. - Rights to the PDP-11PDP-11The PDP-11 was a series of 16-bit minicomputers sold by Digital Equipment Corporation from 1970 into the 1990s, one of a succession of products in the PDP series. The PDP-11 replaced the PDP-8 in many real-time applications, although both product lines lived in parallel for more than 10 years...
line and several PDP-11 operating systems were sold to Mentec in 1994, though DEC continued to produce some PDP-11 hardware for a few years. - Disk and DLTDigital Linear TapeDigital Linear Tape is a magnetic tape data storage technology developed by Digital Equipment Corporation from 1984 onwards. In 1994 the technology was purchased by Quantum Corporation, who currently manufactures drives and licenses the technology and trademark. A variant with higher capacity...
technologies was sold to Quantum Corporation in 1994, immediately propelling Quantum to the No1 spot in disk manufacturing. - Text terminal business (VT100VT100The VT100 is a video terminal that was made by Digital Equipment Corporation . Its detailed attributes became the de facto standard for terminal emulators.-History:...
and its successors) was sold in August 1995 to Boundless Technologies. - CORBAÇorbaChorba , ciorbă , shurpa , shorpo , or sorpa is one of various kinds of soup or stew found in national cuisines across Middle East...
-based product, ObjectBroker, and its messaging software, MessageQ, were sold to BEA Systems, IncBEA SystemsBEA Systems, Inc. specialized in enterprise infrastructure software products known as "middleware", which connect software applications to databases and was acquired by Oracle Corporation on April 29, 2008.- History :...
in March 1997. - In May 1997, DEC sued Intel for allegedly infringing on its Alpha patents in designing the original Pentium, Pentium ProPentium ProThe Pentium Pro is a sixth-generation x86 microprocessor developed and manufactured by Intel introduced in November 1, 1995 . It introduced the P6 microarchitecture and was originally intended to replace the original Pentium in a full range of applications...
, and Pentium IIPentium IIThe Pentium II brand refers to Intel's sixth-generation microarchitecture and x86-compatible microprocessors introduced on May 7, 1997. Containing 7.5 million transistors, the Pentium II featured an improved version of the first P6-generation core of the Pentium Pro, which contained 5.5 million...
chips. As part of a settlement, much of DEC's chip design and fabrication business was sold to Intel. This included DEC's StrongARMStrongARMThe StrongARM is a family of microprocessors that implemented the ARM V4 instruction set architecture . It was developed by Digital Equipment Corporation and later sold to Intel, who continued to manufacture it before replacing it with the XScale....
implementation of the ARM computer architectureARM architectureARM is a 32-bit reduced instruction set computer instruction set architecture developed by ARM Holdings. It was named the Advanced RISC Machine, and before that, the Acorn RISC Machine. The ARM architecture is the most widely used 32-bit ISA in numbers produced...
, which Intel marketed as the XScaleIntel XScaleThe XScale, a microprocessor core, is Intel's and Marvell's implementation of the ARMv5 architecture, and consists of several distinct families: IXP, IXC, IOP, PXA and CE . Intel sold the PXA family to Marvell Technology Group in June 2006....
processors commonly used in Pocket PCPocket PCA Pocket PC is also known by Microsoft as a 'Windows Mobile Classic device'. It is a hardware specification for a handheld-sized computer, personal digital assistant , that runs the Microsoft 'Windows Mobile Classic' operating system...
s. The core of Digital Semiconductor, the Alpha microprocessor group, remained with DEC, while the associated office buildings went to Intel as part of the Hudson, Mass. fabrication site. - Printer business was sold in 1997 to GENICOMGENICOMFrom 1982 to 2003, GENICOM was a leading American manufacturer of computer printers, based in Chantilly, Virginia.-The GE years:In 1954, General Electric decided to decentralize the company into separate business units...
(now TallyGenicom), which then produced models bearing the Digital logo. - Networking business was sold c.1997 to Cabletron SystemsCabletron SystemsCabletron Systems was a major New Hampshire, USA-based provider of networking computer equipment throughout the 1980s and 1990s. Cabletron's design and sales methodologies dramatically reduced the cost of Ethernet networking equipment, covering a wide range of Layer 1 and Layer 2 networking...
, and subsequently spun off as Digital Network Products Group. - DECtalkDECtalkDECtalk was a speech synthesizer and text-to-speech technology developed by Digital Equipment Corporation in the early 1980s, based largely on the work of Dennis Klatt at MIT, whose source-filter algorithm was variously known as KlattTalk or MITalk....
and DECvoice voice products were spun off, and eventually arrived at Fonix.
By 1997 Digital had subsidiary companies in more than two dozen countries including Austria, Australia, Belgium, Brazil, Canada, China (People's Republic), Colombia, Cyprus, Czech Republic, Denmark, Finland, France, Germany, Ireland, Israel, Japan, Jersey States, New Zealand, Netherlands, Norway, Russia, Singapore, Spain, Sweden, Switzerland, Taiwan, and the United Kingdom.
Eventually, on 26 January 1998, what remained of the company (including Digital's multivendor global services organization and customer support centers) was sold to Compaq
Compaq
Compaq Computer Corporation is a personal computer company founded in 1982. Once the largest supplier of personal computing systems in the world, Compaq existed as an independent corporation until 2002, when it was acquired for US$25 billion by Hewlett-Packard....
, which was acquired by Hewlett-Packard
Hewlett-Packard
Hewlett-Packard Company or HP is an American multinational information technology corporation headquartered in Palo Alto, California, USA that provides products, technologies, softwares, solutions and services to consumers, small- and medium-sized businesses and large enterprises, including...
in 2002. The remainder of Digital Semiconductor (the Alpha microprocessor group) was sold to Intel, which placed those employees back in their Hudson, Mass. office which they had vacated when the site was sold to Intel in 1997. Compaq, and later HP, continued to sell many of the former Digital products but rebranded with their own logos. For example, HP now sells what were formerly Digital's StorageWorks disk/tape products, as a result of the Compaq acquisition.
The Digital logo survived for a while after the company ceased to exist, as the logo of Digital GlobalSoft, an IT services company in India (which was a 51 percent subsidiary of Compaq). Digital GlobalSoft was later renamed "HP GlobalSoft" (also known as the "HP Global Delivery India Center" or HP GDIC) and no longer uses the Digital logo.
The digital.com and DEC.com domain names are now owned by Hewlett-Packard and redirect to their US website. Digital once held the Class A
Classful network
A classful network is a network addressing architecture used in the Internet from 1981 until the introduction of Classless Inter-Domain Routing in 1993. The method divides the address space for Internet Protocol Version 4 into five address classes. Each class, coded in the first four bits of the...
IP address
IP address
An Internet Protocol address is a numerical label assigned to each device participating in a computer network that uses the Internet Protocol for communication. An IP address serves two principal functions: host or network interface identification and location addressing...
block 16.0.0.0/8.
The Digital Federal Credit Union
Digital Federal Credit Union
Digital Federal Credit Union is a credit union based in Marlborough, Massachusetts. It has over 340,000 members and is among the top 25 credit unions in the U.S.A. and the largest credit union head quartered in New England as measured by assets. DCU has in excess of $4 Billion USD in assets...
(DCU, now DFCU), which was chartered in 1979 for employees of DEC, is now open to essentially everyone. DFCU has over 700 different sponsors, including the companies that acquired pieces of DEC.
Research
DEC's Research Laboratories (or Research Labs, as they were commonly known) conducted Digital's corporate research. Some of them were operated by CompaqCompaq
Compaq Computer Corporation is a personal computer company founded in 1982. Once the largest supplier of personal computing systems in the world, Compaq existed as an independent corporation until 2002, when it was acquired for US$25 billion by Hewlett-Packard....
and are still operated by Hewlett-Packard
Hewlett-Packard
Hewlett-Packard Company or HP is an American multinational information technology corporation headquartered in Palo Alto, California, USA that provides products, technologies, softwares, solutions and services to consumers, small- and medium-sized businesses and large enterprises, including...
. The laboratories were:
- Western Research Laboratory (WRL) in Palo Alto, CaliforniaPalo Alto, CaliforniaPalo Alto is a California charter city located in the northwest corner of Santa Clara County, in the San Francisco Bay Area of California, United States. The city shares its borders with East Palo Alto, Mountain View, Los Altos, Los Altos Hills, Stanford, Portola Valley, and Menlo Park. It is...
, USA - Systems Research CenterDEC Systems Research CenterThe Systems Research Center was a research laboratory created by Digital Equipment Corporation in 1984, in Palo Alto, California....
(SRC) in Palo Alto, CaliforniaPalo Alto, CaliforniaPalo Alto is a California charter city located in the northwest corner of Santa Clara County, in the San Francisco Bay Area of California, United States. The city shares its borders with East Palo Alto, Mountain View, Los Altos, Los Altos Hills, Stanford, Portola Valley, and Menlo Park. It is...
, USA - Network Systems Laboratory (NSL) in Palo Alto, CaliforniaPalo Alto, CaliforniaPalo Alto is a California charter city located in the northwest corner of Santa Clara County, in the San Francisco Bay Area of California, United States. The city shares its borders with East Palo Alto, Mountain View, Los Altos, Los Altos Hills, Stanford, Portola Valley, and Menlo Park. It is...
, USA - Cambridge Research Laboratory (CRL) in Cambridge, MassachusettsCambridge, MassachusettsCambridge is a city in Middlesex County, Massachusetts, United States, in the Greater Boston area. It was named in honor of the University of Cambridge in England, an important center of the Puritan theology embraced by the town's founders. Cambridge is home to two of the world's most prominent...
, USA - Paris Research Laboratory (PRL) in Paris, France
- MetroWest Technology Campus (MTC) in Maynard, MassachusettsMaynard, MassachusettsMaynard is a town in Middlesex County, Massachusetts, United States. As of the 2010 census, the town population was 10,106.- History :Maynard, located on the Assabet River, was incorporated as an independent municipality in 1871. Prior to that it was known as 'Assabet Village' but was legally...
, USA
Some of the former employees of Digital's Research Labs or Digital's R&D in general include:
- Gordon BellGordon BellC. Gordon Bell is an American computer engineer and manager. An early employee of Digital Equipment Corporation 1960–1966, Bell designed several of their PDP machines and later became Vice President of Engineering 1972-1983, overseeing the development of the VAX...
- Leonard BosackLeonard BosackLeonard Bosack along with his wife Sandy Lerner, is a co-founder of Cisco Systems, an American-based multinational corporation that designs and sells consumer electronics, networking and communications technology and services...
- Henry Burkhardt IIIHenry Burkhardt IIIHenry Burkhardt III was born in Ann Arbor, Michigan, USA, grew up in South Hadley, Massachusetts, and was schooled there. He graduated from Phillips Exeter Academy and attended Princeton University. He began his career as a programmer at Digital Equipment Corporation...
, co-founder of Data General CorporationData GeneralData General was one of the first minicomputer firms from the late 1960s. Three of the four founders were former employees of Digital Equipment Corporation. Their first product, the Data General Nova, was a 16-bit minicomputer...
and Kendall Square ResearchKendall Square ResearchKendall Square Research was a supercomputer company headquartered originally in Kendall Square in Cambridge, Massachusetts in 1986, near MIT. It was co-founded by Steven Frank and Henry Burkhardt III, who had previously helped found Data General and Encore Computer and was one of the original... - Mike BurrowsMichael BurrowsMichael Burrows is widely known as the creator of the Burrows–Wheeler transform. He also was, with Louis Monier, one of the two main creators of AltaVista. He did his first degree in Electronic Engineering with Computer Science at University College London...
- Luca CardelliLuca CardelliLuca Cardelli is an Italian computer scientist who is currently an Assistant Director at Microsoft Research in Cambridge, UK. Cardelli is well-known for his research in type theory and operational semantics. Among other contributions he implemented the first compiler for the functional programming...
- Dave CutlerDave CutlerDavid Neil Cutler, Sr. is an American software engineer, designer and developer of several operating systems including RSX-11M, VMS and VAXELN at Digital Equipment Corporation and Windows at Microsoft.- Personal history :...
- Ed deCastro, co-founder of Data General CorporationData GeneralData General was one of the first minicomputer firms from the late 1960s. Three of the four founders were former employees of Digital Equipment Corporation. Their first product, the Data General Nova, was a 16-bit minicomputer...
- Jim GettysJim GettysJim Gettys is an American computer programmer at Alcatel-Lucent Bell Labs, USA. Until January 2009, he was the Vice President of Software at the One Laptop per Child project, working on the software for the OLPC XO-1. He is one of the original developers of the X Window System at MIT and worked on...
- Henri GouraudHenri Gouraud (computer scientist)Henri Gouraud is a French computer scientist. He is the inventor of Gouraud shading used in computer graphics. He is the great nephew of general Henri Gouraud.During 1964–1967, he studied at École Centrale Paris. He received his Ph.D...
- Jim Gray
- Alan KotokAlan KotokAlan Kotok was an American computer scientist known for his work at Digital Equipment Corporation and at the World Wide Web Consortium...
- Leslie LamportLeslie LamportLeslie Lamport is an American computer scientist. A graduate of the Bronx High School of Science, he received a B.S. in mathematics from the Massachusetts Institute of Technology in 1960, and M.A. and Ph.D. degrees in mathematics from Brandeis University, respectively in 1963 and 1972...
- Butler LampsonButler LampsonButler W. Lampson is a renowned computer scientist.After graduating from the Lawrenceville School , Lampson received his Bachelor's degree in Physics from Harvard University in 1964, and his Ph.D...
- Louis MonierLouis MonierLouis Monier was a founder of the Internet search engine AltaVista. After he left AltaVista, he worked at eBay and then at Google. He left Google in August 2007 to join Cuil, a search engine startup. He was Vice President of Products at Cuil. One month after the launch, he left Cuil, citing...
- Isaac NassiIsaac NassiIsaac "Ike" Nassi is Executive Vice President and Chief Scientist at SAP AG and is based in SAP's Palo Alto location. He is the practice lead of the SAP Research Technology Infrastructure practice, which is focused on guiding SAP's technology infrastructure vision, direction, and execution...
- Radia PerlmanRadia PerlmanRadia Joy Perlman is a software designer and network engineer sometimes referred to as the "Mother of the Internet." She is most famous for her invention of the spanning-tree protocol , which is fundamental to the operation of network bridges, while working for Digital Equipment Corporation...
- Marcus RanumMarcus J. RanumMarcus J. Ranum is a computer and network security researcher and industry leader. He is credited with a number of innovations in firewalls, including building the first Internet email server for the whitehouse.gov domain, and intrusion detection systems...
- Brian Reid
- Paul VixiePaul VixiePaul Vixie is an American Internet pioneer, the author of several RFCs and well-known Unix software.Vixie attended George Washington High School in San Francisco, California. He received a Ph.D in computer science from Keio University in 2011....
Some of the former employees of Digital Equipment Corp who were responsible for developing Alpha and StrongARM
- Daniel W. DobberpuhlDaniel W. DobberpuhlDaniel "Dan" W. Dobberpuhl is an electrical engineer in the United States who led several teams of microprocessor designers.- Background :...
- Jill Keller
- Rich Witek
Some of the work of the Research Labs was published in the Digital Technical Journal, which was in published from 1985 until 1998.
Accomplishments
Digital supported the ANSIAmerican National Standards Institute
The American National Standards Institute is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organization also coordinates U.S. standards with international...
standards, especially the ASCII
ASCII
The American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
character set, which survives in Unicode
Unicode
Unicode is a computing industry standard for the consistent encoding, representation and handling of text expressed in most of the world's writing systems...
and the ISO 8859 character set family. Digital's own Multinational Character Set
Multinational Character Set
The Multinational Character Set is a character encoding created by Digital Equipment Corporation for use in the popular VT220 terminal. It was an 8-bit extension of ASCII that added accented characters, currency symbols, and other character glyphs missing from 7-bit ASCII...
also had a large influence on ISO 8859-1 (Latin-1) and, by extension, Unicode
Unicode
Unicode is a computing industry standard for the consistent encoding, representation and handling of text expressed in most of the world's writing systems...
.
The first versions of the C
C (programming language)
C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....
language and the Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
operating system ran on Digital's PDP
Programmed Data Processor
Programmed Data Processor was the name of a series of minicomputers made by Digital Equipment Corporation. The name 'PDP' intentionally avoided the use of the term 'computer' because, at the time of the first PDPs, computers had a reputation of being large, complicated, and expensive machines, and...
series of computers (first on a PDP-7, then the PDP-11
PDP-11
The PDP-11 was a series of 16-bit minicomputers sold by Digital Equipment Corporation from 1970 into the 1990s, one of a succession of products in the PDP series. The PDP-11 replaced the PDP-8 in many real-time applications, although both product lines lived in parallel for more than 10 years...
's), which were among the first commercially viable minicomputer
Minicomputer
A minicomputer is a class of multi-user computers that lies in the middle range of the computing spectrum, in between the largest multi-user systems and the smallest single-user systems...
s, although for several years Digital itself did not encourage the use of Unix.
Digital also produced the popular VAX
VAX
VAX was an instruction set architecture developed by Digital Equipment Corporation in the mid-1970s. A 32-bit complex instruction set computer ISA, it was designed to extend or replace DEC's various Programmed Data Processor ISAs...
computer family, the first pure 64-bit microprocessor architecture (Alpha AXP
DEC Alpha
Alpha, originally known as Alpha AXP, is a 64-bit reduced instruction set computer instruction set architecture developed by Digital Equipment Corporation , designed to replace the 32-bit VAX complex instruction set computer ISA and its implementations. Alpha was implemented in microprocessors...
), the first commercially successful workstation (the VT-78), and some commercially unsuccessful personal computers. The central computing system of the Soviet reusable Buran spaceship was based on two MicroVAX computers.
Digital produced widely used interactive operating systems, including OS-8
OS/8
OS/8 was the primary operating system used on the PDP-8 minicomputer developed by Digital Equipment Corporation of Maynard, Massachusetts. OS/8 was originally called MS/8 and, for a brief time, PS/8 before Digital settled on the name OS/8 in 1971.A virtually identical version of OS/8, called...
, TOPS-10
TOPS-10
The TOPS-10 System was a computer operating system from Digital Equipment Corporation for the PDP-10 mainframe computer launched in 1967...
, TOPS-20
TOPS-20
The TOPS-20 operating system by Digital Equipment Corporation was the second proprietary OS for the PDP-10 mainframe computer. TOPS-20 began in 1969 as the TENEX operating system of Bolt, Beranek and Newman...
, RSTS/E
RSTS/E
RSTS is a multi-user time-sharing operating system, developed by Digital Equipment Corporation , for the PDP-11 series of 16-bit minicomputers. The first version of RSTS was implemented in 1970 by DEC software engineers that developed the TSS-8 time-sharing operating system for the PDP-8...
, RSX-11
RSX-11
RSX-11 is a family of real-time operating systems mainly for PDP-11 computers created by Digital Equipment Corporation , common in the late 1970s and early 1980s. RSX-11D first appeared on the PDP-11/40 in 1972...
, RT-11
RT-11
RT-11 was a small, single-user real-time operating system for the Digital Equipment Corporation PDP-11 family of 16-bit computers...
, and OpenVMS
OpenVMS
OpenVMS , previously known as VAX-11/VMS, VAX/VMS or VMS, is a computer server operating system that runs on VAX, Alpha and Itanium-based families of computers. Contrary to what its name suggests, OpenVMS is not open source software; however, the source listings are available for purchase...
. PDP computers, in particular the PDP-11
PDP-11
The PDP-11 was a series of 16-bit minicomputers sold by Digital Equipment Corporation from 1970 into the 1990s, one of a succession of products in the PDP series. The PDP-11 replaced the PDP-8 in many real-time applications, although both product lines lived in parallel for more than 10 years...
model, inspired a generation of programmers and software developers. Some PDP-11
PDP-11
The PDP-11 was a series of 16-bit minicomputers sold by Digital Equipment Corporation from 1970 into the 1990s, one of a succession of products in the PDP series. The PDP-11 replaced the PDP-8 in many real-time applications, although both product lines lived in parallel for more than 10 years...
systems more than 25 years old (software and hardware) are still being used to control and monitor factories, transportation systems and nuclear plants. Digital was an early champion of time-sharing
Time-sharing
Time-sharing is the sharing of a computing resource among many users by means of multiprogramming and multi-tasking. Its introduction in the 1960s, and emergence as the prominent model of computing in the 1970s, represents a major technological shift in the history of computing.By allowing a large...
systems.
Digital was to the command-line interface (CLI) what Apple was to the GUI : there was history before and innovation after, but it was Digital's operating systems that put it together in a complete and definitive form . The command-line interfaces found in Digital's systems, eventually codified as DCL
DIGITAL Command Language
DCL, the DIGITAL Command Language, is the standard command languageadopted by most of the operating systems that were sold by the former Digital Equipment Corporation...
, would look familiar to any user of modern microcomputer CLIs; those used in earlier systems, such as CTSS, IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
's JCL
Job Control Language
Job Control Language is a scripting language used on IBM mainframe operating systems to instruct the system on how to run a batch job or start a subsystem....
, or Univac
UNIVAC
UNIVAC is the name of a business unit and division of the Remington Rand company formed by the 1950 purchase of the Eckert-Mauchly Computer Corporation, founded four years earlier by ENIAC inventors J. Presper Eckert and John Mauchly, and the associated line of computers which continues to this day...
's time-sharing systems, would look utterly alien. Many features of the CP/M and MS-DOS CLI show a recognizable family resemblance to Digital's OSes, including command names such as DIR and HELP and the "name-dot-extension" file naming conventions.
VAX and MicroVAX
MicroVAX
The MicroVAX was a family of low-end minicomputers developed and manufactured by Digital Equipment Corporation . The first model, the MicroVAX I, was introduced in 1984...
computers (very widespread in the 1980s) running VMS formed one of the most important proprietary networks, DECnet
DECnet
DECnet is a suite of network protocols created by Digital Equipment Corporation, originally released in 1975 in order to connect two PDP-11 minicomputers. It evolved into one of the first peer-to-peer network architectures, thus transforming DEC into a networking powerhouse in the 1980s...
, which linked business and research facilities. The DECnet
DECnet
DECnet is a suite of network protocols created by Digital Equipment Corporation, originally released in 1975 in order to connect two PDP-11 minicomputers. It evolved into one of the first peer-to-peer network architectures, thus transforming DEC into a networking powerhouse in the 1980s...
protocols formed one of the first peer-to-peer networking standards, with DECnet phase I being released in the mid-1970s. Email, file sharing, and distributed collaborative projects existed within the company long before their value was recognized in the market.
Digital, Intel and Xerox through their collaboration to create the DIX standard, were champions of Ethernet
Ethernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....
, but Digital is the company that made Ethernet commercially successful. Initially, Ethernet-based DECnet and LAT
Local Area Transport
Local Area Transport is a non-routable networking technology developed by Digital Equipment Corporation to provide connection between the DECserver 90, 100, 200, 300, 500, 700 and DECserver 900 terminal servers and Digital's VAX and Alpha and MIPS_architecture host computers via Ethernet, giving...
protocols interconnected VAXes with DECserver terminal servers. Starting with the UNIBUS to Ethernet adapter, multiple generations of Ethernet controllers from Digital were the de facto standard. The CI "computer interconnect" adapter was the industry's first network interface controller to use separate transmit and receive "rings".
Digital also invented clustering, an operating system technology that treated multiple machines as one logical entity. Clustering permitted sharing of pooled disk and tape storage via the HSC50/70/90 and later series of Hierarchical Storage Controllers. HSCs delivered the first hardware RAID 0 and 1 capabilities and the first serial interconnects of multiple storage technologies. This technology was the forerunner to systems like Network of Workstations which are used for massively cooperative tasks such as web-searches and drug research.
The LA36 and LA120 dot matrix printers became industry standards and may have hastened the demise of the Teletype Corporation
Teleprinter
A teleprinter is a electromechanical typewriter that can be used to communicate typed messages from point to point and point to multipoint over a variety of communication channels that range from a simple electrical connection, such as a pair of wires, to the use of radio and microwave as the...
.
The VT100
VT100
The VT100 is a video terminal that was made by Digital Equipment Corporation . Its detailed attributes became the de facto standard for terminal emulators.-History:...
computer terminal
Computer terminal
A computer terminal is an electronic or electromechanical hardware device that is used for entering data into, and displaying data from, a computer or a computing system...
became the industry standard, implementing a useful subset of the ANSI X3.64 standard, and even today terminal emulators such as HyperTerminal
HyperACCESS
HyperACCESS is the name for a number of successive computer communications software, made by Hilgraeve.It was the first software product from Hilgraeve, and it was initially designed to let 8-bit Heath computers communicate over a modem. In 1985 this same product was ported to IBM PCs and...
, PuTTY
PuTTY
PuTTY is a free and open source terminal emulator application which can act as a client for the SSH, Telnet, rlogin, and raw TCP computing protocols and as a serial console client...
and Xterm
Xterm
In computing, xterm is the standard terminal emulator for the X Window System. A user can have many different invocations of xterm running at once on the same display, each of which provides independent input/output for the process running in it .xterm originated prior to the X Window System...
still emulate a VT100 (or its more capable successor, the VT220
VT220
The VT220 was a terminal produced by Digital Equipment Corporation from 1983 to 1987.-Hardware:The VT220 improved on the earlier VT100 series of terminals with a redesigned keyboard, much smaller physical packaging, and a much faster microprocessor...
).
The X Window System
X Window System
The X window system is a computer software system and network protocol that provides a basis for graphical user interfaces and rich input device capability for networked computers...
, the network transparent window system used on UNIX and Linux, and also available on other operating systems, was developed at MIT
Massachusetts Institute of Technology
The Massachusetts Institute of Technology is a private research university located in Cambridge, Massachusetts. MIT has five schools and one college, containing a total of 32 academic departments, with a strong emphasis on scientific and technological education and research.Founded in 1861 in...
jointly between Project Athena
Project Athena
Project Athena was a joint project of MIT, Digital Equipment Corporation, and IBM to produce a campus-wide distributed computing environment for educational use. It was launched in 1983, and research and development ran until June 30, 1991, eight years after it began...
and the Laboratory for Computer Science. Digital was the primary sponsor for this project, which was one of the first large scale free software projects, a contemporary of the GNU Project
GNU Project
The GNU Project is a free software, mass collaboration project, announced on September 27, 1983, by Richard Stallman at MIT. It initiated GNU operating system development in January, 1984...
but not associated with it.
Dave Cutler
Dave Cutler
David Neil Cutler, Sr. is an American software engineer, designer and developer of several operating systems including RSX-11M, VMS and VAXELN at Digital Equipment Corporation and Windows at Microsoft.- Personal history :...
, who led the development of RSX-11
RSX-11
RSX-11 is a family of real-time operating systems mainly for PDP-11 computers created by Digital Equipment Corporation , common in the late 1970s and early 1980s. RSX-11D first appeared on the PDP-11/40 in 1972...
M, RSX-11
RSX-11
RSX-11 is a family of real-time operating systems mainly for PDP-11 computers created by Digital Equipment Corporation , common in the late 1970s and early 1980s. RSX-11D first appeared on the PDP-11/40 in 1972...
M+, VMS and then VAXeln
VAXELN
VAXELN is a real-time operating system for the VAX family of computers produced by the Digital Equipment Corporation of Maynard, Massachusetts.As with RSX-11 and VMS, Dave Cutler was the principal force behind the development of this operating system...
, left Digital in 1988 to lead the development of Windows NT
Windows NT
Windows NT is a family of operating systems produced by Microsoft, the first version of which was released in July 1993. It was a powerful high-level-language-based, processor-independent, multiprocessing, multiuser operating system with features comparable to Unix. It was intended to complement...
which was initially intended to be an "open" operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
that would run on more powerful processors than the existing predominant x86 architecture. While DEC did see value in continuing its X Window System
X Window System
The X window system is a computer software system and network protocol that provides a basis for graphical user interfaces and rich input device capability for networked computers...
environment to support engineering customers, it understood that future mid-range based customers would demand a faster and more user friendly Graphical User Interface
Graphical user interface
In computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...
(GUI), potentially offered through the Windows environment. As Microsoft had experience, technology and patents that would give them upper hand in advancing GUI technology, DEC opted to partner with Microsoft's development of Windows NT for mid-range processors and share in the R&D process of creating faster computers using their RISC Alpha
DEC Alpha
Alpha, originally known as Alpha AXP, is a 64-bit reduced instruction set computer instruction set architecture developed by Digital Equipment Corporation , designed to replace the 32-bit VAX complex instruction set computer ISA and its implementations. Alpha was implemented in microprocessors...
processors. Microsoft was not exclusively bound to the Alpha chip so it pursued other processor makers such as IBM with the PowerPC
PowerPC
PowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...
architecture and eventually capitalized on the emerging strength of the Intel x86 based processors. While most would say that the market determined its own course through the more cost efficient processors produced by Intel, DEC quickly came to realize that its loose partnership with Microsoft would lead to its own undoing in terms of being a major player in the mid-range processor market.
Notes-11 and its follow-on product, VAXnotes, were two of the first examples of online collaboration software, a category that has become to be known as groupware
Collaborative software
Collaborative software is computer software designed to help people involved in a common task achieve goals...
. Len Kawell
Len Kawell
Len Kawell is an engineer and entrepreneur who once worked at Digital Equipment Corporation , where he was one of the designers of the VAX/VMS operating system. He also played a key role in the development of the MicroVAX computer, VAX Notes, and VMC Mail...
, one of the original Notes-11 developers later joined Lotus Development Corporation and contributed to their Lotus Notes
Lotus Notes
Lotus Notes is the client of a collaborative platform originally created by Lotus Development Corp. in 1989. In 1995 Lotus was acquired by IBM and became known as the Lotus Development division of IBM and is now part of the IBM Software Group...
product.
Digital was one of the first businesses connected to the Internet with dec.com, registered in 1985, being one of the first of the now ubiquitous .com domains. gatekeeper.dec.com was a well-known software repository during the pre-World Wide Web days, and Digital was also the first computer vendor to open a public website, on 1 October 1993. The popular AltaVista
AltaVista
AltaVista is a web search engine owned by Yahoo!. AltaVista was once one of the most popular search engines but its popularity declined with the rise of Google...
, created by Digital, was one of the first comprehensive Internet search engines. (Although Lycos
Lycos
Lycos, Inc. is a search engine and web portal established in 1994. Lycos also encompasses a network of email, webhosting, social networking, and entertainment websites.-Corporate history:...
was earlier, it was much more limited.)
DEC invented Digital Linear Tape
Digital Linear Tape
Digital Linear Tape is a magnetic tape data storage technology developed by Digital Equipment Corporation from 1984 onwards. In 1994 the technology was purchased by Quantum Corporation, who currently manufactures drives and licenses the technology and trademark. A variant with higher capacity...
(DLT), formerly known as CompacTape, which began as a compact backup medium for MicroVAX systems, and later grew to capacities of 800 gigabytes.
Work on the first hard-disk-based MP3-player, the Personal Jukebox
Personal Jukebox
The Personal Jukebox was the first commercially sold hard disk digital audio player. Introduced late in 1999, it preceded the Apple iPod and similar players. The original design was developed by Compaq Research starting in May 1998...
, started at the DEC Systems Research Center
DEC Systems Research Center
The Systems Research Center was a research laboratory created by Digital Equipment Corporation in 1984, in Palo Alto, California....
. (The project was started about a month before the merger into Compaq
Compaq
Compaq Computer Corporation is a personal computer company founded in 1982. Once the largest supplier of personal computing systems in the world, Compaq existed as an independent corporation until 2002, when it was acquired for US$25 billion by Hewlett-Packard....
was completed.)
DEC's Western Research Lab created the Itsy Pocket Computer
Itsy Pocket Computer
The Itsy Pocket Computer is a small, low-power, handheld device with a highly flexible interface. It was designed at Digital Equipment Corporation's Western Research Laboratory to encourage novel user interface development—for example, it had accelerometers to detect movement and orientation as...
. This was developed into the Compaq iPaq
IPAQ
iPAQ presently refers to a Pocket PC and personal digital assistant first unveiled by Compaq in April 2000; the name was borrowed from Compaq's earlier iPAQ Desktop Personal Computers. Since Hewlett-Packard's acquisition of Compaq, the product has been marketed by HP. The devices use a Windows...
line of PDA
Personal digital assistant
A personal digital assistant , also known as a palmtop computer, or personal data assistant, is a mobile device that functions as a personal information manager. Current PDAs often have the ability to connect to the Internet...
s, which replaced the Compaq Aero
Compaq Aero
The Compaq Aero was popularized as a line of computer handhelds produced by Compaq Computer Corporation. It was succeeded by the iPAQ line. The Aero name was first used for small sub-notebooks Compaq produced in the mid-90's, the Contura Aero 4/25 and 4/33c....
PDA.
User organizations
Originally the users' groupUsers' group
A users' group is a type of club focused on the use of a particular technology, usually computer-related....
was called DECUS
DECUS
The Digital Equipment Computer Users' Society was an independent computer user group related to Digital Equipment Corporation.The Connect User Group Community, formed from the consolidation in May, 2008 of DECUS, Encompass, HP-Interex, and ITUG is Hewlett-Packard’s largest user community...
(Digital Equipment Computer User Society) during the 1960s to 1990s. When Compaq
Compaq
Compaq Computer Corporation is a personal computer company founded in 1982. Once the largest supplier of personal computing systems in the world, Compaq existed as an independent corporation until 2002, when it was acquired for US$25 billion by Hewlett-Packard....
acquired Digital in 1998, the users group was renamed CUO, the Compaq Users' Organisation. When HP
Hewlett-Packard
Hewlett-Packard Company or HP is an American multinational information technology corporation headquartered in Palo Alto, California, USA that provides products, technologies, softwares, solutions and services to consumers, small- and medium-sized businesses and large enterprises, including...
acquired Compaq
Compaq
Compaq Computer Corporation is a personal computer company founded in 1982. Once the largest supplier of personal computing systems in the world, Compaq existed as an independent corporation until 2002, when it was acquired for US$25 billion by Hewlett-Packard....
in 2002, CUO became HP-Interex
HP-Interex
HP-Interex was the EMEA HP Users Organisation, representing the user community of Hewlett-Packard computers.The Connect User Group Community, formed from the consolidation in May, 2008 of HP-Interex, DECUS, Encompass, and ITUG, is Hewlett-Packard’s largest user community representing more than...
, although there are still DECUS groups in several countries. In the United States, the organization is represented by the Encompass
Encompass
Connect, Your Independent HP Business Technology Community, Connect User Group CommunityFormed from the consolidation of DECUS, Encompass, HP-Interex, and ITUG in May, 2008, Connect is Hewlett-Packard’s largest user community representing more than 50,000 participants...
organization.
External links
- GBell's CyberMuseum for Digital Equipment Corp (DEC)
- Rise and Fall of Digital (Equipment Corporation), a company chronicle at a German computer museum
- Ken Olsen, New England Economic Adventure