Personal computer

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Apple II-IMG 7067c.jpg
Apple II , built in 1977
Commodore PET2001.jpg
Commodore PET 2001 , built in 1977
IBM PC 5150.jpg
IBM Personal Computer , built in 1981
HP Tablet PC running Windows XP (Tablet PC edition) (2006) .jpg
Tablet PC , with an integrated keyboard since 2002
and mostly without or
with a dockable keyboard since 2010 . The first and
last option gives the impression of
a laptop

A personal computer ( . Engl ., Dt to "personal computer", shortly PC ) is a multi-purpose computer whose size and capabilities make it suitable for individual personal use in daily life; In contrast to previous computer models , use is no longer restricted to computer experts, technicians or scientists. The concept goes back to an idea from the 1970s , founded by hackers . Ease of use and an affordable price for private households were important prerequisites for the concept, which has been technically implemented since 1976. Only devices of this type triggered what the journalist Steven Levy as computer revolution called. In contrast, devices from earlier times are occasionally referred to as personal computers , although they do not fit into the concept.

A PC is a microcomputer , in contrast to a mini or mainframe computer . It appears, for example, as a desktop , notebook or tablet computer and can run under any operating system such as Windows , iOS or Unix . The spectrum ranges from home computers to typical workstation computers . Workstation computers with above-average performance for computing and memory-intensive applications are called workstations ; their price can be many times that of a PC.

Although already common in the 1970s, the term “personal computer”, especially its short form “PC”, was increasingly and exclusively associated with the IBM personal computer and its IBM-compatible PC replicas from 1981 onwards . This was due to the marketing of IBM with its successful advertising. The link referred to the x86 processor family built into it and the DOS and Windows operating systems running on it . In addition, the term is occasionally associated with the type of x86 desktop PC , which, however, contradicts the type and designation of alternative x86 PC devices such as the Microsoft tablet PC .


Components of a current PC; the illustration shows a typical desktop PC

A current or only a few years old PC typically has the following components:

  1. Main board (mainboard, motherboard) with interfaces to all subsequent components
  2. Main processor central processing unit (CPU)
  3. Processor cooler
  4. Main memory (main memory, Random Access Memory , abbreviated RAM)
  5. Graphics card (in a desktop PC via PCIe interface, also obsolete via AGP or PCI ; very often also as an alternative to the graphics chip integrated on the motherboard or in the CPU)
  6. power adapter
  7. Hard disk drive or SSD (mass storage)
  8. Optical drive (usually a DVD burner, more rarely a BD-ROM / DVD burner combo drive or BD burner, outdated DVD-ROM drive or DVD-ROM / CD burner combo drive; especially on mobile computers sometimes not integrated, but connected as a separate device via USB )
  9. monitor
  10. Keyboard (on keyboard- less tablet PCs , this form of data input is simulated virtually via the integrated touch-sensitive monitor)
  11. Mouse , alternatively as a touchpad on mobile computers ; on a tablet PC, the graphical user interface is operated directly via the monitor without a mouse

Also (not in the picture):

  • Hard disk / removable storage controller
    • SATA and / or ATA interface, as a plug-in card. Usually integrated on the motherboard.
  • Housing made of sheet metal, design based on Intel's ATX specification (or µATX or E-ATX or XL-ATX )
  • optional: additional plug-in card (s) via the PCI or PCIe interfaces
  • optional: case fans are not mandatory in the ATX standard, but are usually necessary for adequate cooling in modern systems
  • optional: printer

Strictly speaking, peripheral devices such as monitors, keyboards, mice and printers do not necessarily count as components of the personal computer.


“The 'brain' [the computer] could one day get down to our [human] level and help with our income tax and accounting calculations. But that's speculation and so far there is no evidence of it. "

- British newspaper The Star in a June 1949 news article about the EDSAC computer, long before the personal computer era.

The journalist Steven Levy published the world's first book in 1984, which deals with the early history of the personal computer and focuses on the developers and their motivation. It is entitled "Hackers - Heroes of the Computer Revolution" . In it, he describes a group of hackers - a kind of very pronounced technology enthusiasts - who could inspire in the 1970s the idea of a personal computer. Their aim was to integrate computers into everyday life, to make them publicly available to everyone, up to and including the visionary goal of the time to enable a broad mass of people to use universally applicable personal computers.

In order to achieve this goal, the personal computer had to meet a number of requirements: It was important to have a practical size that would allow the average person to transport it and, for example, install it on a desk. It had to be available to private households, affordable and universally applicable. A handling that is suitable for the general public was decisive. This made intuitive and universal data input and output necessary, which went far beyond the toggle switches and light-emitting diodes of the previously common computers in the lower price segment. So that the use was not only reserved for electronics specialists, kits also had to be available with ready-soldered components that the computer dealer or the user can easily assemble. Operating both the computer and the application software installed on it should not require any special training beyond the respective operating instructions. In addition, the end user should be given the opportunity to freely program his personal computer. It was only devices of this kind that triggered what Levy calls the computer revolution in his above-mentioned book.

This idea was dismissed as absurd by the prevailing industry at the time. So to Thomas J. Watson , early head of IBM, declared in 1943: "I think there is a world market for maybe five computers." If not to that extent, companies like Texas Instruments , Fairchild , IBM, and DEC still basically followed this decree in the 1970s . When asked about the development of a personal computer by an employee, DEC boss Ken Olsen rejected this proposal in 1977 on the grounds that he could not imagine any private person who would want such a computer.

Ted Nelson dedicated a book in 1974 with the title “Computer Lib” to the idea of ​​a publicly accessible computer, the preliminary stage on the way to the personal computer , which became the standard work among those who supported this idea at the time. In the same year Lee Felsenstein founded the “Community Memory” project, which provided access to a computer via public terminals in record stores and libraries. The project was groundbreaking for the time and had the practical use of a bulletin board on which you could add any contribution via ADD and find it with FIND.

Due to the size and cost of the computers of the 1950s and 1960s, which mostly filled entire rooms or, as minicomputers, were about the size of a cabinet, they could hardly be assigned personally to a single person. That only changed gradually when TTL chips came onto the market from 1961 and microprocessors from 1971 and the core memories that had prevailed until then were replaced by semiconductor memories . Such components have been affordable for private households and thus for building a PC since the mid-1970s.

Around the Homebrew Computer Club founded by Fred Moore and Gordon French in March 1975 in the San Francisco region , on the west coast of the United States, tech-savvy people, hackers, met, as Levy writes. From practical projects and developments to the birth of a completely new industry in Silicon Valley , they have made a decisive contribution to the development of the personal computer. Regarding the PC, you repeatedly drew attention to yourself with concepts and practical developments. Many computer pioneers emerged from their ranks; Members of this association founded numerous computer companies. The Homebrew Computer Club is therefore referred to as the “melting pot for an entire industry”.

Controversy about the first personal computer

In his book mentioned above, Levy sets the limit to the personal computer where he sees the visionary goal achieved at the time, which the developers he interviewed saw in the personal computer. From this point of view, the Apple I, published in April 1976, is considered the world's first personal computer, followed in 1977 by the Commodore PET, the Tandy TRS-80 Model 1 and the Apple II .

However, the above requirements for a PC are not stipulated; the term personal computer has no fixed definition. The naming of the Apple I as the first personal computer is therefore not without controversy.

There are actually several computers depending on their weighting, each of which is referred to as the world's first personal computer. If, for example, one neglects the point of simple handling that is suitable for the general public and does not necessarily assume that the computer can be used universally, the Simon from 1949, affordable for private households for the first time, is the first personal computer; a relay-based learning computer that was only available as a do-it-yourself kit. If it is a purely electronic computer with integrated circuits that was delivered as a fully assembled device, the Kenbak-1 from 1971 is considered the first PC. If a series-produced microcomputer is assumed, which uses a microprocessor as the central processing unit ( CPU ) , then it is the Micral N from 1973. Some consider the Altair 8800 from 1975 to be the world's first personal computer, even if it is not much different from the Micral N. All of the computers mentioned so far have one thing in common: a personal computer must be affordable for private households. But even this point does not claim to be general; People who attach particular importance to ease of use, but who do not attach importance to price or availability, call the Xerox Alto from 1973 the first PC in the world.

The meaning of the word lies in its use. Levy's distinction is supported by the fact that the PC is colloquially not associated with a device that is operated with a toggle switch and lamp, but with a keyboard and monitor. The Apple I, available for $ 666, was undisputedly the first affordable personal computer for private households to come with an operating system and all the ports needed to run it in a modern way with a keyboard and monitor. Some components that were important for operation were not included in the scope of delivery; the keyboard, the housing and the power supply had to be purchased separately and without a home television set as a replacement for a monitor and a cassette recorder as a data storage device, it could not work. In January 1977, the world's first PC of this type was presented with a complete set of ready-to-use equipment: the Commodore PET 2001, available for 795 US dollars. The four-year-old Xerox Alto was also operated via keyboard and monitor and even had a mouse control, however In contrast to these two devices, it is classified as a workstation due to its high price. A workstation can cost many times that of a personal computer. Its production cost was 1,973 at 12,000 US dollars (which the purchasing power equivalent of 2020 related to a value of about 69,000 US dollars); Lead developer Charles P. Thacker estimates that the retail price would have been as high as $ 40,000 in 1973 (the Xerox Alto was not officially on sale at the time). Even before the Xerox Alto there were other graphic workstations with keyboard and monitor, such as the IMLAC PDS-1 from 1970 and the IBM 2250 from 1964 .

Their ease of use and low price have made personal computers largely suitable and attractive for average private users since 1976. It was only the overwhelming sales success of such devices by other companies (partly outside the sector, partly newly founded) that prompted the predominant computer industry to adopt the idea of ​​the personal computer , develop its own products and bring them onto the market since 1981. The marketing of IBM with the advertisement for their IBM Personal Computer , IBM-PC for short, was so successful that the term “Personal Computer” was often associated with this brand, even though this PC was priced marginally compared to the original PC concept was. Instead, the much cheaper replicas, the " IBM PC-compatible computers " , established themselves as one of the most successful platforms for personal computers; the PCs with Windows operating systems and x86 processors available on the market are based on the continuous further development of the IBM design at the time. It is thanks to the successful advertising by IBM that the IBM PC 5150 from 1981 is often referred to as the world's first personal computer. IBM wasn't even the first company to advertise its product as a personal computer ; The HP-9100A desk calculator from 1968 was first referred to in advertising as a personal computer , followed by the HP-9830 from 1972 and the Altair 8800 from 1975 .

The forerunners of the modern personal computer

1949, Edmund C. Berkeley with Simon before the first computer for home use. It consisted of 50  relays and is designed for 300 dollars sold in the form of plans, of which were sold in the first ten years, more than 400 copies. It is a digital, programmable and largely automated computer that was compact for its time and affordable for private households. If you add the components, it could be built for around 500 US dollars at the time (which corresponds to a value of around 5,400 US dollars in terms of purchasing power in 2020). No special training is required for its operation beyond the operating instructions. It already fulfills many requirements for a personal computer and is therefore considered by some people to be the first PC in the world. With its five control buttons, the punched tape as a program sequence memory and the five lights as an output unit, which could display numbers from 0 to 4, this device does not technically correspond to what is understood by a personal computer. The Simon was specially developed as a learning computer , which should bring the user closer to the basic functionality of a computer. The situation is similar with the turntable-based GENIAC from 1955, the analog tube-based Heathkit EC-1 from 1959 and the relay computer Minivac 601 from 1961.

The world's first freely programmable desktop calculator, the Programma 101 from Olivetti , was released in 1965 for $ 3,200. Three years later, the Hewlett-Packard Company launched the HP-9100A, a programmable computing device that already offered more display and programming options than the Programma 101, but at $ 4,900, it cost around twice the average gross annual salary at the time . This computer was referred to as a personal computer in an advertisement for the first time in the literature, although it does not correspond to today's understanding of a PC in terms of price or technology . It is noteworthy that the performance of both desktop computers was provided without the use of integrated circuits .

In 1967 a book was published entitled "How To Build a Working Digital Computer" by the authors Edward Alcosser, James P. Phillips and Allen M. Wolk. The book describes how you can build a simple computer from everyday objects such as paper clips for switches and a tin can for the drum storage. In 1969, COMSPACE sold a professionally assembled version of this learning computer under the name Arkay CT-650 for $ 1,000 .

With the IMLAC PDS-1 , a networked graphics workstation from the manufacturer Imlac Corporation of Needham , a small company from Massachusetts , USA , appeared in 1970 . It was noteworthy that this company developed a very efficient design that made it possible for them to offer their computer for sale for as little as 8300 US dollars (in comparison, the technically comparable IBM 2250 from 1964 still cost 280,000 US dollars ). The PDS-1 was a pioneer on the way to a graphic personal computer, in parts comparable to the much more expensive Xerox Alto from 1973 .

In September 1971, the Kenbak-1, developed by John Blankenbaker , was released for $ 750. Although the first microprocessors had been available since 1971, his computer did not use a microprocessor; Blankenbaker constructed the machine on a single circuit board with TTL chips . The Kenbak-1 is sometimes referred to as the world's first personal computer. Since it did not receive an operating system , all actions had to be programmed in pure machine code using a series of buttons and switches located on the front. The output consisted of a series of lights on the back. Devices like this were largely unsuitable and hardly attractive for average private users; the Kenbak-1 therefore neither fits into the concept of the personal computer nor does it technically correspond to what is colloquially understood as a personal computer.

The HP-9830 published in 1972 was the first desktop computer with a BASIC interpreter integrated in the ROM . In contrast to the HP-9100A and the Programma 101, it had a full alphanumeric keyboard and an alphanumeric display, thus bridging the gap between a conventional desktop computer and an all-in-one desktop computer. It is true that this device only had a single screen line with only 32 characters and was hardly affordable for private households at 5,975 US dollars (which corresponds to a value of around error US dollars in 2020 ); Nevertheless, it came quite close to today's understanding of the term personal computer. Therefore, some people consider it the world's first PC.

The Micral N was another forerunner of the personal computer; the first mass-produced computer of its kind with a microprocessor, in this case an Intel 8008 . It was developed in France by André Truong Trong Thi and François Gernelle and has been sold there for 8500 FF since 1973 (the equivalent of 1750 US dollars, which corresponds to a value of around 10,000 US dollars in 2020 purchasing power). Data input and output was initially carried out using a toggle switch and lamp, but since 1974 it has been supplied with a keyboard and a screen for an extra charge; Hard drives were available from 1975. In terms of operation, this computer has since corresponded to the understanding of a PC, but not in terms of price. Also in 1973 the Scelbi-8H appeared , another microcomputer with an Intel 8008.

In 1973, the HP-65 was the world's first fully programmable calculator for $ 795 . However, since it does not have an alphanumeric display, it can be viewed as a sophisticated programmable computer that is technically further away from a PC than, for example, the one year older HP-9830.

The company Xerox PARC presented their Xerox Alto to the world in 1973 , a device about the size of a refrigerator. With a typewriter-like keyboard, a three-button mouse, an additional small 5-key chord keyboard for special commands, an object-oriented operating system, a screen with a graphical user interface (English, graphical user interface , short GUI ) and an Ethernet interface he was groundbreaking for the future personal computer. However, this workstation was intended as a scientific device; it was neither affordable for private use nor available for trade during this period and was only offered for sale from 1978 at a price of 32,000 US dollars (based on purchasing power in 2020 that would be around 125,000 US dollars).

The Mark-8 appeared in 1974 and was another microcomputer, operated by an Intel 8008. Only the construction plan and the circuit board of the Mark-8 were sold; it was therefore only available as a do-it-yourself kit.

With the Altair 8800 from MITS , a series-produced device came onto the market in 1975, which is also known as a personal computer and was available as a kit for 397 US dollars, as a complete device for 695 US dollars . Within the early scene around the homebrew computer club , the Altair 8800 enjoyed great popularity and served the members of the club as a centerpiece for their own extensions. The equipment with a bus plug-in system for expansion cards based on the S-100 bus standard was pioneering. With its toggle switches as input unit and light-emitting diodes as output unit, however, this device does not technically correspond to what is understood by a personal computer. To use Altair BASIC or CP / M as a command line operating system, a text terminal had to be connected via the serial interface (the RS-232 interface). It was similar with the KIM-1 from MOS Technology , which appeared in the same year and which already had a 24-key input unit in pocket calculator format for direct input of HEX codes and a 6-digit 7-segment LED display as Output unit.

The IBM 5100 , published in 1975, featured a typewriter-like keyboard, an integrated monitor and a cassette drive for removable data storage. In purely technical terms, he was able to demonstrate everything that is understood by a personal computer. However, the price of 9,000 to 20,000 US dollars at that time (around 43,000 to 95,000 US dollars based on the year 2020) was far too high for private households, which is why it did not fit into the concept of the personal computer either.

First personal computers with typewriter-like keyboard and screen

Apple I and II

Steve Wozniak (known on the scene as The Woz ) was a prominent member of the Homebrew Computer Club . In April 1976 he presented his computer to the public, which was technically far superior to the Altair 8800 . As the first device in the world, it was affordable for private households at 666 US dollars and at the same time corresponded to the modern operating concept of a personal computer: His computer used a typewriter-like keyboard as an input unit and a screen (initially in the form of a converted television set) as an output unit. The only peripheral device was a cassette interface, which, in combination with a conventional cassette recorder, allowed programs to be stored on audio cassettes and then reloaded from them. Apple was one of the companies that emerged from the Homebrew Computer Club, with Steve Wozniak being one of the founders alongside Steve Jobs and Ronald Wayne . His computer was indeed developed the company was founded, but then produced there in series under the name Apple I sold. As a single-board computer , it was delivered in the form of a fully equipped circuit board and supplemented by a power supply unit, housing and keyboard by the dealer or end user before it could be operated on the television at home.

The successor model, the Apple II , was now also delivered in a complete version with a housing, power supply unit, keyboard and monitor, and later even with a mouse. At the same time, it was the last industrial PC designed entirely by a single person, Steve Wozniak. It was unveiled in the United States in April 1977 and priced at $ 1,298 (which equates to around $ 5,500 in 2020). When it was launched, it had eight free slots in the 8-bit Apple bus system with which it could be used for various applications (e.g. word processing, games, control technology) by inserting the appropriate expansion card. This property of a computer, which can therefore be individually adapted to the needs of the consumer using slots, is considered to be the basic property of a PC. In addition, this computer could already represent colors and reproduce sounds. The Apple II series was an open system , which means that all essential construction details were published.

Commodore PET and Tandy TRS

The world's first industrially manufactured PC in a complete version (including housing, power supply unit, keyboard, monitor and mass storage device in the form of a data set ) was presented in January 1977: the Commodore PET 2001 , which went over the counter for 795 US dollars. In August of the same year, the Tandy TRS-80 Model 1 followed for $ 599. In terms of performance, both devices were similar to the Apple II , but had no slots for expansion cards, no color display and no sound output. The PET had the (parallel) IEC bus that is widespread in professional measurement technology , which meant that it was widely used in research and industry.

Other providers

In addition to the models from Apple and Commodore, there were other similar PC models from other manufacturers at this time, including Sharp MZ-80K (1978), Acorn System 1 (1979) and Sinclair ZX80 (1980).


On August 12, 1981, the first IBM PC 5150 was presented. In terms of price, it was at the upper limit of commercially available PCs. In the basic configuration, it could be purchased for USD 1,565 (without floppy disk drives and monitor, but with a TV connection) or for USD 3,005 in full (this corresponds to around USD 8,400 in 2020). In the maximum configuration with more memory and color graphics, it was offered for 6,000 US dollars. IBM used its market leadership at the time for (mainframe) data processing systems and managed to get its IBM PC to be used as a workstation computer in numerous companies.

The unit was using the Intel - 8088 equipped processor and had an 8- bit - ISA bus system. The following models were also equipped with processors from Intel. The 8086 processor (6-12 MHz clock; CPU word width 16 bits) introduced by Intel one year before the 8088 processor (4.77–9.5 MHz clock; internal CPU word width 16 bits; system data bus 8 bits) Bit; system bus 16 bit) ensured that the abbreviation “ x86 architecture” was established for the series .

The IBM PC was sold from 1981 to 1995 exclusively with the IBM operating system , PC DOS , which had been licensed from Microsoft to IBM. The collaboration that began in 1981 ended in 1985. Both companies then continued to develop the operating system separately, but paid attention to mutual compatibility . Since then, the MS-DOS operating system from Microsoft has only existed on computers that are similar in construction to those of IBM.

The company IBM disclosed the basic construction of its PC and created an informal industry standard, with which it defined the current device class of " IBM PC-compatible computers " . Numerous inexpensive replicas and continuations of the IBM PC by other companies made the platform very successful both in the workplace and in the home. In February 1984 the IBM Portable Personal Computer was introduced, an early precursor to the laptops , later called notebooks (as a class of portable personal computers).

Home computers, Apple and IBM compatible PCs

C64 with "Personal Computer" lettering

From the 1980s onwards, other devices than home computers came onto the market with TV output and sound output . The best-selling models were the Commodore C64 and the devices of the Amiga series, such as different versions of the Atari ST .

In the German-speaking world in the 1980s, the English word personal (personal) was sometimes incorrectly associated with German staff (workers, employees). A derivation from personal computers to professional use of corresponding devices has therefore become common in this country. For example, in the media, medium-performance devices were sometimes classified as "[not] approaching the performance of a personal computer" when such devices were in fact personal computers. Since the Amiga series and the Atari ST at home computer prices outperformed the IBM PC XT and AT and partly used the housing shape of the professional devices, the erroneous distinction disappeared at the end of the 1980s.

IBM compatible i486 desktop PC (1996, motherboard from 1994)

Since IBM did not have a monopoly on the components used (with the exception of the BIOS ), Compaq was able to bring the first computer compatible with the IBM PC to the market in 1983 . Companies in East Asia in particular created a number of replicas, in Germany it was companies like Commodore and later Schneider . The market that developed in this way led through competition to falling prices and increased innovation.

At the beginning, the number of units was by no means comparable to today's. The market situation at the end of 1983 loud for professional microcomputers (without home computers ):

providers Units delivered Delivery shares
in percent
Commodore 14,500 17.0
Apple 12,000 14.0
IBM 9,700 11.5
Hewlett Packard 7,100 8.5

Market positions of the six most important providers of professional microphones at the end of 1983:

rank providers Sales market share
in percent
1 Commodore 25.0
2 Apple 16.5
3 Hewlett Packard 11.0
4th Tandy 8.5
5 Triumph eagle 5.0
6th IBM 4.5

Personal computers first played a significant role in the American Christmas business in 1984. However, both IBM and Apple had produced too many devices and complained of a disappointing result in the spring of 1985. Many dealers stayed on the PC, and customers complained, “They couldn't do much with the machines.” An Apple dealer even gave an Italian bike to everyone who bought a computer.

Apple computers were partly copied, but the company was able to hold its own (with a significantly reduced market share). The Apple II line was discontinued in the early 1990s; only the Macintosh series was produced. At first, apart from Sun , Apple was the only manufacturer that developed hardware and software (operating system and user programs) itself and marketed them together.

Most other manufacturers, such as Commodore and Schneider, largely disappeared from the market in the early 1990s or turned back to other business areas ( Atari ). The more recent PC models from IBM, such as the PC 300GL, remained largely unknown and went down on the market alongside products from other manufacturers. The attempt by IBM to recapture the market with the Personal System / 2 series and the operating system OS / 2 went similarly .

In the private sector, home computers and PCs were initially used for experimentation, learning and playing. They were increasingly used in areas such as word processing , databases and spreadsheets and thus found their way into everyday business.

Modern personal computers

PC construction from 2005 ( midi tower )
Mid-range PC construction from early 2017 in the same housing model
Mini-PC built in 2004 from a barebone system

The performance of personal computers has increased steadily since their creation ( Moore's law ). In addition to the tasks of word processing and spreadsheets, the multimedia area became one of the main areas of application. In order to meet the requirements of the latest PC games, there are "gaming PCs" that are equipped with high computing power and very powerful graphics cards.

In modern PCs, regardless of the operating system used, hardware based on the x86 architecture has been used practically throughout , which historically dates back to the IBM personal computer from 1981 or its so-called IBM-compatible further developments. Of the other computer architectures for single-user computers, the PowerPC models from Apple were available until the beginning of 2006 , before Apple also replaced them with x86 models. PowerPC computers from Apple are no longer supported by the operating system since Mac OS X Snow Leopard .

In addition to the market-leading Windows, the operating systems used are mainly Unixoid operating systems, especially Linux and BSD . Since the introduction of Mac OS X, the Apple operating system has been a Unix derivative which, in contrast to the various Linux distributions and free BSD operating systems , is certified as UNIX from version 10.5 ( see also the list of operating systems ).


In line with technical developments, the designs also changed over time. The first IBM PC was literally a desktop computer , he and his contemporaries from other manufacturers had cases in landscape format and stood on the work table. On top of them stood the monitor with a screen diagonal of only 10 to 13 inches at the time. As these desktop PCs got a little larger over time and were not only more and more in the way on the desk, but the increasingly larger monitor models on the computer were ergonomically more and more unfavorable, one went to the PC case standing next to the monitor in portrait format about, the Tower models. The latter was then differentiated into Big Towers , Midi Towers and other gradations. Depending on the height of the tower and the preferences of the user, there are many personal computers under or next to the table.

Since the early 1980s, parallel efforts have been made to develop portable computers . This usually refers to a device with the technology and dimensions of a desktop computer, but whose mostly suitcase-shaped housing is designed for regular transport. The first devices of this type were the Osborne-1 and the Kaypro in 1981 and the SX64 in 1983 . You absolutely need a power grid connection for operation; Battery operation was out of the question, especially because these models were still equipped with integrated picture tubes that required a lot of energy.

The device class of mobile computers (with battery operation) have been developed since the availability of inexpensive LCD displays . In 1981 the GRiD Compass 1100 appeared and opened the class of the still quite heavy lap computers ( called laptops ); the first commercially successful laptop appeared in 1986 with the IBM PC Convertible . The term notebook tends to be used for the medium-sized and lighter versions of mobile computers, while the term netbook is used for a significantly smaller device without an optical drive, the keys of which can also be too small for use in the ten-finger system.

A special design of a personal computer that belongs to the handheld devices is the tablet PC . Even if tablets existed before that, they did not gain greater attention until 2002 with Microsoft's Windows XP Tablet PC Edition ; the breakthrough for this device class did not come until 2010 with the release of Apple's iPad .


The number of PCs sold worldwide continued to decline in 2013, with a total of around 316 million units sold, almost 26 million of them in Europe (more precisely: EMEA - the economic region that includes Europe, the Middle East and Africa). Overall, sales fell by around 10% compared to 2012. This decrease is u. a. due to the continued spread of tablet computers and smartphones .

In the past, the majority of PCs sold were used as workstation computers in business and administration, but many private households also had PCs.

In emerging countries in particular , people tend to have a smartphone for communication and a tablet computer rather than a computer instead of a PC with internet access.

Environmental impact

Environmental impacts caused by PCs have been recognized and researched since 2005 at the latest. The environmental impacts are considerable due to the high sales figures and various pollutants in production; they pollute the environment, especially around production facilities and through the consumption of materials and energy. The area in computer science that deals with the environmental aspects of PCs and computer hardware in general is Green IT .

Resource consumption

According to a study from 2003, 240 liters of fossil fuel are needed to manufacture a computer including a 17-inch tube monitor. Assuming a total weight of the system - including the tube monitor  - of around 24 kilograms, that corresponds to ten times its own weight. In addition, around 22 kg of chemicals and 1500 kg of water are required.

Power consumption

In order to be able to operate your PC as economically as possible at present (as of 2013), it is advisable to observe certain industry standards . For power supplies this is the " 80-PLUS " certification in bronze, silver, gold platinum or titanium according to the ENERGY STAR guideline of the US EPA.

For a long time, a single PC in a desktop version used a largely constant electrical power of around 50 W. This value lasted until the introduction of the Intel Pentium III processor at the end of the 1990s. In the period that followed, these values ​​rose rapidly to well over 100 W for the processor alone and sometimes over 200 W for the entire computer. There was a trend reversal in 2004, when the processor manufacturer AMD used functions for the dynamic change of the processor clock for the first time for its AMD Athlon 64 which had only been used in notebooks . Thanks to this function, which is available in all processors, power consumption has dropped again, at least without a dedicated graphics card and without complex calculations. Significant deviations from this result when the processor is actually used, and even more when a dedicated graphics card is used, which - even if only a normal desktop is to be displayed - already requires between 10 and 80 W.

Laptops and notebooks that are supposed to be mobile and designed for battery operation try to use electrical energy as sparingly as possible in order to achieve the longest possible battery life. Depending on the speed requirement and load, between approx. 10 W and (e.g. for mobile 3D graphics) well over 60 W are achieved. The values ​​are largely constant over time; Improvements in battery technology are mainly used to reduce the size of the housing and only to a small extent to extend the running time. Also industrial PCs often use laptop technology, however, less because of the power consumption, but of moving parts in the form of fans to increase to dispense and the mechanical robustness. The even smaller single-board computers, UMPC or netbooks require even less electrical power with sometimes less than 10 W, although here mostly concessions have to be made in terms of computing power.

Due to the high use of resources in production, it does not make sense to buy an economical new device solely with a view to saving energy , since the energy consumption in use is comparatively low compared to the energy consumption in production and disposal . The additional energy consumption resulting from the new production can - if this is possible at all with normal private use - only be compensated for after several years through the lower power consumption.

Complex calculations such as 3D images in computer games , image calculations by graphics programs or video processing increase the energy requirement to 300 W. Powerful PCs with very fast processors achieve values ​​of up to 425 W. High-performance graphics cards each require up to 275 W, so that with two graphics cards Full load of the system power consumption of almost 1000 W is possible.


Personal computers are made up of a wide variety of components, mainly electronics and metal. In Germany they are taken back by the manufacturers via collection structures in accordance with the Electronic Scrap Ordinance. Owners are obliged to bring the devices to the collection points separately from the residual waste . Returns are free of charge in Germany. In the course of scrapping, many electronic components are recycled, for example to save rare earth metals .

Obsolete, still functional PCs or components can also be sold or passed on to hobbyists or people in need - as part of the linux4afrika project . Often old devices are also illegally shipped to third world countries , where, often neglecting work and environmental protection measures , the valuable metals are extracted and the rest is deposited in landfills ( electronic waste dump in Guiyu in China or electronic waste dump in Agbogbloshie in Ghana ).

Technology centers and economic effects of PC trading on the world

A large proportion of imported products come from manufacturers in the United States , followed by Taiwan. Most PCs have an Intel or AMD processor. The most common graphics cards come from US companies such as Nvidia , Intel or AMD.

In the case of PC mainboards, on the other hand, the Republic of China (Taiwan) leads the production, with products from Asus , Gigabyte Technology and Micro-Star International including the most commonly installed sound chips from Realtek . The Taiwanese company Foxconn is the leader in the actual manufacture of the boards .

In contrast, the market leader in external sound solutions is Creative Technology (Singapore) with the Soundblaster series. US suppliers such as Seagate Technology and Western Digital are leading the market for hard drives (HDDs) . When it comes to power supplies, the manufacturers Sea Sonic , Thermaltake and Enermax from Taiwan lead the production, whereby the general quality criterion for power supplies, the 80-PLUS certification in bronze, silver, gold, platinum and titanium comes from the US environmental authority EPA and has established itself as the market standard. Power supplies without the 80 PLUS EPA seal of approval are practically unsaleable.

When it comes to memory modules , US manufacturers such as Corsair Memory , Mushkin , Micron Technology and Kingston Technology lead the market, followed by G.Skill and TeamGroup from Taiwan. The memory chips are mainly manufactured by the Korean manufacturers Samsung and Hynix as well as by the American company Micron Technology.

The three largest FPGA manufacturers Xilinx , Altera and Atmel are also based in the USA. European manufacturers only have a negligible share in the production of current personal computers and are heavily dependent on imports. The US market leader Microsoft, with the most frequently used operating system, Windows , also makes a large contribution to value creation in the USA. For the United Kingdom, however, ARM Limited , which licenses the ARM architecture worldwide, and Raspberry Pi for market leadership among single-board computers with the Raspberry Pi, is advantageous here . However, the Eurozone itself does not benefit from this for the time being.

Development of European alternatives

The development of European alternatives hardly got beyond processor design, as all major home computer manufacturers such as Commodore and Atari had their headquarters in the USA as early as the 1980s , as did the processor manufacturers MOS Technology , Motorola and Zilog .

The most European in this context was the Acorn Archimedes from the British company Acorn with its own ARM architecture , as well as the Dutch company ASML , which manufactures the EUV lithography exposure machines, the key technology for Intel and AMD processor production.

Development in Germany

10 euro commemorative coin for the 100th birthday of Konrad Zuse

The development in Germany had a certain significance until the 1960s with the computers of the Zuse KG of the computer pioneer Konrad Zuse . The Z1 up to the 5-channel punched tape-controlled drawing table Zuse Z64 Graphomat were important in-house developments with international recognition.

In 1969, Siemens AG completely took over Zuse KG and outsourced the computer division to the new company Siemens Nixdorf in Munich , which later merged to become Fujitsu Siemens Computers . The focus was on POS systems and computer trading . The Nixdorf Quattro 8870 mainframe computer with the Business BASIC operating system and the COMET application software, which appeared in 1975, had a certain degree of success in companies until the 1980s. The CPU (an unspecified 1585.01, probably a plagiarism) already came from the company Digital Computer Controls, Inc. from the USA.

Development of Russian alternatives

CPU development in Russia is based primarily on the Russian Elbrus 2000 microprocessor, for which there is even a dedicated 130 nanometer manufacturing process based on the equipment taken over from AMD from Fab 30.

In May 2015, an up-to-date Elbrus home PC based on the Elbrus 4C chip made headlines thanks to the fluid display of the 2004 Doom BFG game .

In the past, Russia was content with copying the Zilog Z80 , whose derivatives such as the MME U880 also provided the basis for computers in the GDR .

Development of Japanese alternatives

In 1982 NEC presented the PC-98 , which was equipped with an Intel 8086 processor and 128 kB of RAM. It was developed from the PC-88 , which was still using a Zilog Z80 . Although the PC-98 was very similar to the IBM PC, it used the 16-bit wide C-bus that was already present in the PC-88, while the ISA bus was used on the IBM PC . The PC-98 was so successful in Japan for over a decade that one can speak of the “IBM PC of Japan”. The performance of the built-in components (CPU, RAM, storage capacities) was constantly adjusted during this time. It was only with the rise of Windows that the PC-98 was increasingly pushed out of the market. Since Windows 3.1 and Windows 95 were also available in versions for the PC-98, customers increasingly turned to cheaper PCs that were also Windows-capable. Within 5 years, the market share in Japan fell from 60 to 33%. In 1997 the production of the PC-98 was stopped.

In the 1980s, the typical Japanese home computer was generally considered to be the MSX computer, which had established itself there as an alternative to the C64 . Although the MSX-1 was essentially based on US manufacturers, again the Z80 processor from Zilog, the graphics chip from Texas Instruments and the sound chip from General Instrument . Japanese own brands were the successors of the MSX-2 and MSX turbo R with the Yamaha v9958 graphics processor and Yamaha YM2149 / YM2413 sound chip. The 7.16 MHz fast R800 CPU for the MSX turbo R was Zilog-compatible, but in fact also an in-house development of the Japanese ASCII Corporation and was manufactured by Mitsui Bussan . In 1987 the X68000 home computer from Sharp followed with an HD68HC000 CPU produced by Hitachi (later the 68000 series from Motorola were installed) and in 1989 the FM Towns with the first serial built-in CD-ROM drive, which, however, was already based on the Intel 8086 architecture based.

Development in Africa

Africa plays a role in the global PC trade, as most of the computer and electronic waste ends up here. For example, children at the electronic scrap dump in Agbogbloshie , the world's most toxic rubbish dump, in a slum on the outskirts of the capital Accra in Ghana, recycle a lot of old devices by removing aluminum from the monitor frame and copper from the cables.

Development in the Middle East

In the Arab countries, as in Africa, there was practically no development. Israel is most likely to develop part of the computer technology with the arms manufacturer Rafael Advanced Defense Systems . The Iron Dome missile interception system and the Trophy (APS) system for defending tanks were already significant in-house developments .


  • John Markoff : What the dormouse said. How the 60s Counterculture Shaped the Personal Computer Industry . New York, Viking 2005, ISBN 0-670-03382-0
  • Scott Mueller: PC Hardware Superbibel, with DVD-ROM . Markt und Technik, Munich 2005, ISBN 3-8272-6794-3
  • Hans Messmer, Klaus Dembowski: PC hardware book. Structure, functionality, programming . Addison-Wesley, Munich a. a. 2003, ISBN 3-8273-2014-3
  • Andreas Stiller: Happy oldies. The PC celebrates its 20th birthday. In: c't . June 18, 2001, pp. 172-177
  • Roy A. Allan: A Bibliography of the Personal Computer . 2005 (english)

Web links

Wiktionary: Personal Computer  - explanations of meanings, origins of words, synonyms, translations
Wiktionary: PC  - explanations of meanings, word origins, synonyms, translations
Commons : Personal Computer  - collection of pictures, videos and audio files
Wikibooks: Computer Hardware for Beginners  - Learning and Teaching Materials

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