The history of personal computer as mass-market consumer electronic devices effectively began in 1977 with the introduction of microcomputers, although some mainframe and maincomputers had been applied as single-user systems much earlier. A personal computer is one intended for interactive individual use, as opposed to a mainframe computer where the end user's requests are filtered through operating staff, or a time sharing system in which one large processor is shared by many individuals. After the development of the microprocessor, individual personal computers were low enough in cost that they eventually became affordable consumer goods. Early personal computers – generally called microcomputers– were sold often inelectronic kit form and in limited numbers, and were of interest mostly to hobbyists and technicians.
Six years later a manufacturer took the risk of referring to their product this way, when Hewlett-Packard advertised their "Powerful Computing Genie" as "The New Hewlett-Packard 9100Apersonal computer".[1] This advertisement was deemed too extreme for the target audience and replaced with a much drier ad for the HP 9100A programmable calculator.[2][3]
Over the next seven years the phrase had gained enough recognition that when Byte magazine published its first edition, it referred to its readers as "[in] the personal computing field",[4] andCreative Computing defined the personal computer as a "non-(time)shared system containing sufficient processing power and storage capabilities to satisfy the needs of an individual user."[5]Two years later, when what Byte was to call the "1977 Trinity" of pre-assembled small computers hit the markets,[6] the Apple II and the PET 2001 were advertised as personal computers,[7][8]while the TRS-80 was a described as a microcomputer used for household tasks including "personal financial management". By 1979 over half a million microcomputers were sold and the youth of the day had a new concept of the personal computer.[9]
Contents
[show]Introduction[edit]
Mainframes, minicomputers, and microcomputers[edit]
Computer terminals were used for time sharing access to central computers. Before the introduction of the microprocessor in the early 1970s, computers were generally large, costly systems owned by large corporations, universities, government agencies, and similar-sized institutions. End users generally did not directly interact with the machine, but instead would prepare tasks for the computer on off-line equipment, such as card punches. A number of assignments for the computer would be gathered up and processed in batch mode. After the job had completed, users could collect the results. In some cases it could take hours or days between submitting a job to the computing center and receiving the output.
A more interactive form of computer use developed commercially by the middle 1960s. In a time-sharing system, multiple computer terminals let many people share the use of one mainframe computer processor. This was common in business applications and in science and engineering.
A different model of computer use was foreshadowed by the way in which early, pre-commercial, experimental computers were used, where one user had exclusive use of a processor.[10] In places such as MIT, students with access to some of the first computers experimented with applications that would today be typical of a personal computer; for example, computer aided drafting was foreshadowed by T-square, a program written in 1961, and an ancestor of today's computer games was found in Spacewar! in 1962. Some of the first computers that might be called "personal" were early minicomputers such as the LINC and PDP-8, and later on VAX and larger minicomputers from Digital Equipment Corporation (DEC), Data General, Prime Computer, and others. By today's standards they were very large (about the size of a refrigerator) and cost prohibitive (typically tens of thousands of US dollars). However, they were much smaller, less expensive, and generally simpler to operate than many of the mainframe computers of the time. Therefore, they were accessible for individual laboratories and research projects. Minicomputers largely freed these organizations from the batch processing and bureaucracy of a commercial or university computing center.
In addition, minicomputers were relatively interactive and soon had their own operating systems. The minicomputer Xerox Alto (1973) was a landmark step in the development of personal computers, because of its graphical user interface, bit-mapped high resolution screen, large internal and external memory storage, mouse, and special software.[11]
As early as 1945, Vannevar Bush, in an essay called As We May Think, outlined a possible solution to the growing problem of information storage and retrieval. In what was later to be called The Mother of All Demos, SRI researcherDouglas Engelbart in 1968 gave a preview of what would become the staples of daily working life in the 21st century – e-mail, hypertext, word processing, video conferencing, and the mouse. The demo was the culmination of research in Engelbart's Augmentation Research Center laboratory, which concentrated on applying computer technology to facilitate creative human thought.
Microprocessor and cost reduction[edit]
The minicomputer ancestors of the modern personal computer used early integrated circuit (microchip) technology, which reduced size and cost, but they contained no microprocessor. This meant that they were still large and difficult to manufacture just like their mainframe predecessors. After the "computer-on-a-chip" was commercialized, the cost to manufacture a computer system dropped dramatically. The arithmetic, logic, and control functions that previously occupied several costly circuit boards were now available in one integrated circuit, making it possible to produce them in high volume. Concurrently, advances in the development of solid state memory eliminated the bulky, costly, and power-hungry magnetic core memory used in prior generations of computers.
A few researchers at places such as SRI and Xerox PARC were working on computers that a single person could use and that could be connected by fast, versatile networks: not home computers, but personal ones.
After the 1972 introduction of the Intel 4004, microprocessor costs declined rapidly. In 1974 the American electronics magazine Radio-Electronics described the Mark-8 computer kit, based on the Intel 8008 processor. In January of the following year, Popular Electronics magazine published an article describing a kit based on the Intel 8080, a somewhat more powerful and easier to use processor. The Altair 8800 sold remarkably well even though initial memory size was limited to a few hundred bytes and there was no software available. However, the Altair kit was much less costly than an Intel development system of the time and so was purchased by companies interested in developing microprocessor control for their own products. Expansion memory boards and peripherals were soon listed by the original manufacturer, and later by plug compatible manufacturers. The very first Microsoft product was a 4 kilobyte paper tape BASIC interpreter, which allowed users to develop programs in a higher-level language. The alternative was to hand-assemble machine code that could be directly loaded into the microcomputer's memory using a front panel of toggle switches, pushbuttons and LED displays. While the hardware front panel emulated those used by early mainframe and minicomputers, after a very short time I/O through a terminal was the preferred human/machine interface, and front panels became extinct.
The beginnings of the personal computer industry[edit]
IBM 610[edit]
Main article: IBM 610
The IBM 610 was designed between 1948 and 1957 by John Lentz at the Watson Lab at Columbia University as the Personal Automatic Computer (PAC) and announced by IBM as the 610 Auto-Point in 1957. The IBM 610 is according to Columbia University, the first personal computer because it was the first programmable computer intended for use by one person (e.g. in an office) and controlled from a keyboard. Although it was faulted for its speed, the IBM 610 handled floating-point arithmetic naturally. With a price tag of $55,000, only 180 units were produced.[12]
Olivetti Programma 101[edit]
Main article: Programma 101
The Programma 101 was the first commercially produced "desktop computer",[13][14] designed and produced by the Italian company Olivetti and presented at the 1965 New York World's Fair. Over 44,000 units were sold worldwide; in the US its cost at launch was $3,200. The Programma 101 had many of the features incorporated in modern personal computers, such as memory, keyboard, printing unit, magnetic card reader/recorder, control and arithmetic unit[15] and is considered by many as the first commercially produced desktop computer, showing the world that it was possible to create a desktop computer[16] (HP later copied the Programma 101 architecture for its HP9100 series).[17] [18]
MIR[edit]
Main article: MIR (computer)
The Soviet MIR series of computers was developed from 1965 to 1969 in a group headed by Victor Glushkov. It was designed as a relatively small-scale computer for use in engineering and scientific applications and contained a hardware implementation of a high-level programming language. Another innovative feature for that time was the user interface combining a keyboard with a monitor and light pen for correcting texts and drawing on screen.[19]
K-202[edit]
Main article: K-202
First 16-bit non-kit desktop computer. First 1 megaflops minicomputer, not in line with the ES EVM. Made by Polish scientists, IT & electronics engineer Jacek Karpiński, Ewa Jezierska, Andrzej Ziemkiewicz, Zbysław Szwaj, Teresa Pajkowska and Krzysztof Jarosławski. Circa 30 sold.
Kenbak-1[edit]
Main article: Kenbak-1
The Kenbak-1 is considered by the Computer History Museum to be the world's first personal computer. It was designed and invented by John Blankenbaker of Kenbak Corporation in 1970, and was first sold in early 1971. Unlike a modern personal computer, the Kenbak-1 was built of small-scale integrated circuits, and did not use a microprocessor. The system first sold for US$750. Only around 40 machines were ever built and sold. In 1973, production of the Kenbak-1 stopped as Kenbak Corporation folded.
With only 256 bytes of memory, an 8-bit word size, and input and output restricted to lights and switches, the Kenbak-1 was most useful for learning the principles of programming but not capable of running application programs.
Datapoint 2200[edit]
Main article: Datapoint 2200
A programmable terminal called the Datapoint 2200 is the earliest known device that bears some significant resemblance to the modern personal computer, with a screen, keyboard, and program storage.[20] It was made by CTC (now known as Datapoint) in 1970 and was a complete system in a small case bearing the approximate footprint of an IBM Selectric typewriter. The system's CPU was constructed from a variety of discrete components, although the company had commissioned Intel to develop a single-chip processing unit; there was a falling out between CTC and Intel, and the chip Intel had developed wasn't used. Intel soon released a modified version of that chip as the Intel 8008, the world's first 8-bit microprocessor.[21] The needs and requirements of the Datapoint 2200 therefore determined the nature of the 8008, upon which all successive processors used in IBM-compatible PCs were based. Additionally, the design of the Datapoint 2200's multi-chip CPU and the final design of the Intel 8008 were so similar that the two are largely software-compatible; therefore, the Datapoint 2200, from a practical perspective, can be regarded as if it were indeed powered by an 8008, which makes it a strong candidate for the title of "first microcomputer" as well.
Micral N[edit]
Main article: Micral
The French company R2E was formed by two former engineers of the Intertechnique company to sell their Intel 8008-based microcomputer design. The system was originally developed at the Institut National de la Recherche Agronomique to automate hygrometric measurements. The system ran at 500 kHz and included 16 kB of memory, and sold for 8500 Francs, about $1300US.
A bus, called Pluribus, was introduced that allowed connection of up to 14 boards. Boards for digital I/O, analog I/O, memory, floppy disk were available from R2E. The Micral operating system was initially called Sysmic, and was later renamed Prologue.
R2E was absorbed by Groupe Bull in 1978. Although Groupe Bull continued the production of Micral computers, it was not interested in the personal computer market, and Micral computers were mostly confined to highway toll gates (where they remained in service until 1992) and similar niche markets.
Xerox Alto and Star[edit]
 | This section does not cite any references or sources. (June 2008) |
The Xerox Alto, developed at Xerox PARC in 1973, was the first computer to use a mouse, the desktop metaphor, and a graphical user interface (GUI), concepts first introduced by Douglas Engelbart while atInternational. It was the first example of what would today be recognized as a complete personal computer.
In 1981, Xerox Corporation introduced the Xerox Star workstation, officially known as the "8010 Star Information System". Drawing upon its predecessor, the Xerox Alto, it was the first commercial system to incorporate various technologies that today have become commonplace in personal computers, including a bit-mapped display, a windows-based graphical user interface, icons, folders, mouse, Ethernet networking,file servers, print servers and e-mail. It also included a programming language system called Smalltalk.
While its use was limited to the engineers at Xerox PARC, the Alto had features years ahead of its time. Both the Xerox Alto and the Xerox Star would inspire the Apple Lisa and the Apple Macintosh.
IBM 5100[edit]
IBM 5100 was a desktop computer introduced in September 1975, six years before the IBM PC. It was the evolution of a prototype called the SCAMP (Special Computer APL Machine Portable) that IBM demonstrated in 1973. In January 1978 IBM announced the IBM 5110, its larger cousin. The 5100 was withdrawn in March 1982.
When the PC was introduced in 1981, it was originally designated as the IBM 5150, putting it in the "5100" series, though its architecture wasn't directly descended from the IBM 5100.
Altair 8800[edit]
Main article: Altair 8800
Development of the single-chip microprocessor was the gateway to the popularization of cheap, easy to use, and truly personal computers. It was only a matter of time before one such design was able to hit a sweet spot in terms of pricing and performance, and that machine is generally considered to be the Altair 8800, from MITS, a small company that produced electronics kits for hobbyists.
The Altair was introduced in a Popular Electronics magazine article in the January 1975 issue. In keeping with MITS's earlier projects, the Altair was sold in kit form, although a relatively complex one consisting of four circuit boards and many parts. Priced at only $400, the Altair tapped into pent-up demand and surprised its creators when it generated thousands of orders in the first month. Unable to keep up with demand, MITS eventually sold the design after about 10,000 kits had shipped.
The introduction of the Altair spawned an entire industry based on the basic layout and internal design. New companies like Cromemco started up to supply add-on kits, while Microsoft was founded to supply a BASIC interpreter for the systems. Soon after a number of complete "clone" designs, typified by the IMSAI 8080, appeared on the market. This led to a wide variety of systems based on the S-100 bus introduced with the Altair, machines of generally improved performance, quality and ease-of-use.
The Altair, and early clones, were relatively difficult to use. The machines contained no operating system in ROM, so starting it up required a machine language program to be entered by hand via front-panel switches, one location at a time. The program was typically a small driver for an attached paper tape reader, which would then be used to read in another "real" program. Later systems added bootstrapping code to improve this process, and the machines became almost universally associated with the CP/M operating system, loaded from floppy disk.
The Altair created a new industry of microcomputers and computer kits, with many others following, such as a wave of small business computers in the late 1970s based on the Intel 8080, Zilog Z80 and Intel 8085 microprocessor chips. Most ran the CP/M-80 operating system developed by Gary Kildall at Digital Research. CP/M-80 was the first popular microcomputer operating system to be used by many different hardware vendors, and many software packages were written for it, such as WordStar and dBase II.
Homebrew Computer Club[edit]
Although the Altair spawned an entire business, another side effect it had was to demonstrate that the microprocessor had so reduced the cost and complexity of building a microcomputer that anyone with an interest could build their own. Many such hobbyists met and traded notes at the meetings of the Homebrew Computer Club (HCC) in Silicon Valley. Although the HCC was relatively short-lived, its influence on the development of the modern PC was enormous.
Members of the group complained that microcomputers would never become commonplace if they still had to be built up, from parts like the original Altair, or even in terms of assembling the various add-ons that turned the machine into a useful system. What they felt was needed was an all-in-one system. Out of this desire came the Sol-20 computer, which placed an entire S-100 system – QWERTY keyboard, CPU, display card, memory and ports – into an attractive single box. The systems were packaged with a cassette tape interface for storage and a 12" monochrome monitor. Complete with a copy of BASIC, the system sold for US$2,100. About 10,000 Sol-20 systems were sold.
Although the Sol-20 was the first all-in-one system that we would recognize today, the basic concept was already rippling through other members of the group, and interested external companies.
Other machines of the era[edit]
Other 1977 machines that were important within the hobbyist community at the time included the Exidy Sorcerer, the NorthStar Horizon, the Cromemco Z-2, and the Heathkit H8.
1977 and the emergence of the "Trinity"[edit]
See also: Microcomputer revolution
By 1976 there were several firms racing to introduce the first truly successful commercial personal computers. Three machines, the Apple II, PET 2001 and TRS-80 were all released in 1977,[22] eventually selling millions of machines.Byte magazine later referred to their launch as the "1977 Trinity".
PET[edit]
Main article: Commodore PET
Chuck Peddle designed the Commodore PET (short for Personal Electronic Transactor) around his MOS 6502 processor. It was essentially a single-board computer with a new display chip (the MOS 6545) driving a small built-in monochrome monitor with 40×25 character graphics. The processor card, keyboard, monitor and cassette drive were all mounted in a single metal case. In 1982, Byte referred to the PET design as "the world's first personal computer".[23]
The PET shipped in two models; the 2001-4 with 4 kB of RAM, or the 2001-8 with 8 kB. The machine also included a built-in Datassette for data storage located on the front of the case, which left little room for the keyboard. The 2001 was announced in June 1977 and the first 100 units were shipped in mid October 1977.[24] However they remained back-ordered for months, and to ease deliveries they eventually canceled the 4 kB version early the next year.
Although the machine was fairly successful, there were frequent complaints about the tiny calculator-like keyboard, often referred to as a "Chiclet keyboard" due to the keys' resemblance to the popular gum candy. This was addressed in the upgraded "dash N" and "dash B" versions of the 2001, which put the cassette outside the case, and included a much larger keyboard with a full stroke non-click motion. Internally a newer and simpler motherboard was used, along with an upgrade in memory to 8, 16, or 32 KB, known as the 2001-N-8, 2001-N-16 or 2001-N-32, respectively.
The PET was the least successful of the 1977 Trinity machines, with under 1 million sales.[25]
Apple II[edit]
Main article: Apple II
Steve Wozniak (known as "Woz"), a regular visitor to Homebrew Computer Club meetings, designed the single-board Apple I computer and first demonstrated it there. With specifications in hand and an order for 100 machines at $500.00 US Dollars each from the Byte Shop, Woz and his friend Steve Jobs founded Apple Computer.
About 200 of the machines sold before the company announced the Apple II as a complete computer. It had color graphics, a full QWERTY keyboard, and internal slots for expansion, which were mounted in a high quality streamlined plastic case. The monitor and I/O devices were sold separately. The original Apple II operating system was only the built-in BASIC interpreter contained in ROM. Apple DOS was added to support the diskette drive; the last version was "Apple DOS 3.3".
Its higher price and lack of floating point BASIC, along with a lack of retail distribution sites, caused it to lag in sales behind the other Trinity machines until 1979, when it surpassed the PET. It was again pushed into 4th place when Atari introduced its popular Atari 8-bit systems.[26]
Despite slow initial sales, the Apple II's lifetime was about eight years longer than other machines, and so accumulated the highest total sales. By 1985 2.1 million had sold and more than 4 million Apple II's were shipped by the end of its production in 1993.[25]
TRS-80[edit]
Main article: TRS-80
Tandy Corporation introduced the TRS-80, retroactively known as the Model I as improved models were introduced. The Model I combined the motherboard and keyboard into one unit with a separate monitor and power supply. Although the PET and the Apple II offered certain features that were greatly advanced in comparison, Tandy's 3000+ Radio Shack storefronts ensured that it would have widespread distribution that neither Apple nor Commodore could touch.
The Model I used a Zilog Z80 processor clocked at 1.77 MHz (the later models were shipped with a Z80A processor). The basic model originally shipped with 4 kB of RAM, and later 16 kB. Its other strong features were its full stroke QWERTY keyboard, small size, well written Floating BASIC and inclusion of a monitor and tape deck for approximately half the cost of the Apple II.
The Model I ran into some trouble meeting FCC regulations on radio interference due to its plastic case and exterior cables. Apple had resolved this issue with an interior metallic foil but this patch wouldn't work on the Model I.[27] Since the Model II and Model III were already in production Tandy decided to stop manufacturing the Model I. Radio Shack had sold 1.5 million Model I's by the cancellation in 1981.[25]
Home computers[edit]
See also: Home computer
Although the success of the Trinity machines was relatively limited in overall terms, as component prices continued to fall, many companies entered the computer business. This led to an explosion of low-cost machines known as home computers that sold millions of units before the market imploded in a price war in the early 1980s.
Atari 400/800[edit]
Main article: Atari 8-bit family
Atari was a well-known brand in the late 1970s, both due to their hit arcade games like Pong, as well as the hugely successful Atari VCS game console. Realizing that the VCS would have a limited lifetime in the market before a technically advanced competitor came along, Atari decided they would be that competitor, and started work on a new console design that was much more advanced.
While these designs were being developed, the Trinity machines hit the market with considerable fanfare. Atari's management decided to change their work to a home computer system instead. Their knowledge of the home market through the VCS resulted in machines that were almost indestructible and just as easy to use as a games machine – simply plug in a cartridge and go. The new machines were first introduced as the 400 and 800 in 1978, but production problems meant widespread sales did not start until the next year.
At the time, the machines offered what was then much higher performance than contemporary designs and a number of graphics and sound features that no other microcomputer could match. They became very popular as a result, quickly eclipsing the Trinity machines in sales. In spite of a promising start with about 600,000 sold by 1981, the looming price war left Atari in a bad position. They were unable to compete effectively with Commodore, and only about 2 million machines were produced by the end of their production run.[25]
Sinclair[edit]
Sinclair Research Ltd is a British consumer electronics company founded by Sir Clive Sinclair in Cambridge. Originally incorporated in 1973 as Ablesdeal Ltd. and renamed to Westminster Mail Order Ltd and then Sinclair Instrument Ltd. in 1975, it remained dormant until 1976, when it was activated with the intension of continuing Sinclair's commercial work from his earlier company Sinclair Radionics; it adopted the name Sinclair Research in 1981. In 1980, Clive Sinclair entered the home computer market with the ZX80 at £99.95, at the time the cheapest personal computer for sale in the UK. In 1982 the ZX Spectrum was released, later becoming Britain's best selling computer, competing aggressively against Commodore and Amstrad. At the height of its success, and largely inspired by the Japanese Fifth Generation Computer programme, the company established the "MetaLab" research centre at Milton Hall (near Cambridge), in order to pursue artificial intelligence, wafer-scale integration, formal verification and other advanced projects. The combination of the failures of the Sinclair QL computer and the TV80 led to financial difficulties in 1985, and a year later Sinclair sold the rights to their computer products and brand name to Amstrad. Sinclair Research Ltd still exists today as a one man company, continuing to market Sir Clive Sinclair's newest inventions.
ZX80
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