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 Computer Wallpapers Biography

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The minicomputer ancestors of the modern personal computer used early integrated circuit (microchip) technology, which reduced size and cost, but they contained nomicroprocessor. 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-assemblemachine 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]

§Simon[edit]

Main article: Simon (computer)
Simon [13] was a project developed by Edmund Berkeley and presented in a thirteen articles series issued in Radio-Electronics magazine, from October 1950. Although there were far more advanced machines at the time of its construction, the Simon represented the first experience of building an automatic simple digital computer, for educational purposes. In 1950, it was sold for US$600.
§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 IBMas the 610 Auto-Point in 1957. 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.[14]
§Olivetti Programma 101[edit]

Main article: Programma 101
The Programma 101 was the first commercially produced "desktop computer",[15][16] 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[17] and is considered by many as the first commercially produced desktop computer, showing the world that it was possible to create a desktop computer[18] (HP later copied the Programma 101 architecture for its HP9100 series).[19] [20]
§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.[21]
§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
1970: 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.[22] 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.[23] 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 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]



1973: Xerox Alto
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 at International. 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
>1975: 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 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,[24] eventually selling millions of machines. Byte magazine later referred to their launch as the "1977 Trinity".
§PET[edit]

Main article: Commodore PET
Oct. 1977: Commodore PET.
Chuck Peddle designed the Commodore PET (short for Personal Electronic Transactor) around his MOS 6502 processor. It was essentially asingle-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".[25]
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.[26] However they remained back-ordered for months, and to ease deliveries they eventually canceled the 4 kB version early the next year
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