Personal Computer
A personal computer (English " personal computers" or " private computer ", also briefly PC) is a micro computer which is in contrast to a minicomputer or mainframe of a single user operated and used personally.
The spectrum ranges from the area of privately used home computer up to the typical workstation computer that is used for the management of tasks, for example in business and management applications with no above-average demands on the hardware. Above average performance PCs for compute-and memory -intensive applications are also referred to as a workstation; their cost can be a multiple of a typical PC.
Although already common in the 1970s, the term was linked personal computers as of 1981 in the parlance increasingly and exclusively with the series of the IBM Personal Computer and the kind of the " IBM PC compatible " replicas. However, this limitation is considered outdated.
- 4.1 resource consumption
- 4.2 Power Consumption
- 4.3 applications
- 4.4 Disposal
Construction
A recent PC usually has the following components:
- Controller for hard drives / removable storage (typically SATA and / or ATA interface ), usually integrated on the motherboard
- Housing made of sheet metal design based on the ATX specification
- Optional: another card (s) via the interfaces PCI, PCIe
- Optional: case fans are provided in the ATX standard is not mandatory, but needed in modern systems to ensure sufficient cooling usually
- Optional: printer
Strictly not include peripherals such as monitor, keyboard, mouse and printer to the computer components.
Development
Due to the size and cost of computers in the 1950s and 1960s, mostly filled entire rooms or as a mini computer cabinet were about large, this could hardly be assigned to employees 'personal'. This only changed when the microprocessors came in the 1970s on the market and the then prevalent core memory were gradually supplanted by semiconductor memory. Only in this way the development of real personal computers has become possible that could be placed readily on or in the vicinity of an office workstation.
The precursor of the modern personal computer
1949, Edmund C. Berkeley with Simon the first digital programmable computer for home use before. It consisted of 50 relays and was distributed in the form of plans, of which were sold in the first ten years, more than 400 copies.
The Hewlett- Packard Company introduced with the HP- 9100A 1968 programmable computing device on the market, which cost about twice the average gross annual salary. It is noteworthy that these services have been rendered without the use of integrated circuits. The computer was first described in an advertisement in the literature as a personal computer, although he neither price nor technically corresponds to the current understanding of a PC.
The company Xerox PARC Xerox Alto introduced in 1973 its the world public, about a refrigerator -sized device. With a keyboard, a 3 -button mouse, an additional small 5-button chord keyboard for special instructions, a screen with Graphical User Interface ( engl. graphical user interface, GUI short ) and an Ethernet interface, it was groundbreaking for future staff computer. This workstation was, however, intended as a scientific apparatus; she was neither affordable for home use, still a produced in masses device and not available for trading.
With the Altair 8800 MITS was produced in 1975, a series device on the market, which is also referred to as personal computers and had to purchase a kit for 397 U.S. dollars, as a complete unit for 695 U.S. dollars. Pioneering was the fitting of a bus system to plug expansion cards after the S-100 bus standard. With its toggle switches as an input unit and LEDs as output unit, however, this device complies technically with what is today understood a personal computer.
It was similar to the published in the same year KIM -1 from MOS Technology, which after all, already had a 24-key input unit in the calculator format for direct input of HEX code as well as a 6-digit 7-segment LED display as an output unit.
Journalist Steven Levy described in his 1984 book " Hackers - Heroes of the Computer Revolution " a subculture of hackers, who in the 1970s in the region of San Francisco, the West Coast of the United States, was born. Around founded by Fred Moore in March 1975 Homebrew Computer Club is interested in technology people who were enthusiastic about the idea of a personal computer met. Starting from the idea that computers make for all people accessible to the public, and even use in the home, on practical projects and developments, to the birth of an entirely new industry in Silicon Valley, they have driven the development of the personal computer decisive. Within the early scene enjoyed the MITS Altair 8800 very popular and served the members of the club as a centerpiece for your own extensions. They made regarding the PC again with concepts and practical developments attention. Later members founded this association many computer companies.
In contrast, the idea that the computer will find its place in households and every person should be freely accessible, dismissed by the dominant industry in the 1970s as absurd. So is Thomas J. Watson, the early head of IBM, declared in 1943: "I think there is a world market for maybe five computers." Though not to this extent, companies such as Texas Instruments, Fairchild, IBM, and DEC followed basically still this decree. Approached by an employee on the development of a computer for private households, pointed DEC chief Ken Olsen 1977 this proposal on the grounds of himself that he could not imagine any individual who wants to have such a computer. Only the outstanding sales success of such devices by other (partly outside the industry, newly founded in part ) Companies should encourage the prevailing industry decided to adopt the idea of the personal computer to develop their own products and bring to market.
First personal computer with typewriter- style keyboard and screen
Apple I and II
A prominent member of the Homebrew Computer Club, Steve Wozniak ( in the scene known as The Woz ), developed in 1976 in a garage entirely his own computer, the Altair 8800 was the technically far superior and the first device in the world are not only priced to the modern notions of a personal computer corresponded: His computer had a typewriter-like keyboard as an input unit and a display screen ( initially in the form of a repurposed television ) as the output unit. Apple was one of the companies that emerged from the Homebrew Computer Club, where Steve Wozniak is next to Steve Jobs and Ronald Wayne is one of the company founders. His computer was indeed developed before founding the company, but then produced there in series, and sold under the name Apple I for 666 U.S. dollars. As a single board it was delivered in the form of a fully assembled board and supplemented by the dealer or end user to a power supply, case and keyboard before he could be operated on domestic television.
Its successor, the Apple II, was now delivered in complete version with a chassis, power supply, keyboard and monitor, later even with a mouse. At the same time he was the last industrially manufactured PC, which was completely designed by a single person, Steve Wozniak. It was introduced in April 1977 in the U.S. and offered for a price of 1298 U.S. dollars. At its launch, it had eight free slots of the 8- bit Apple - bus system with which it could be used by inserting the corresponding expansion card for different applications (eg word processing, games, control engineering ). This property of a computer that can be adapted by slots individually to the needs of the consumer, then, is now regarded as a basic property of a PC; it is an open system. Moreover, have already shown colors and tones are reproduced with this computer.
Commodore PET and Tandy TRS
The world's first PC in a complete design ( including case, power supply, keyboard, monitor, and mass storage in the form of a Datasette ) industrially produced was presented in January 1977, the Commodore PET 2001, which went for 795 dollars over the counter. In August of the same year, the Tandy TRS 80 Model 1 was followed for 599 U.S. dollars. From the performance data of manufacture both devices were similar to the Apple II, but had no slots for expansion cards, no color display and no sound. The PET had the spread in the professional measurement technology (parallel) IEC bus, which meant that he became widespread in research and industry.
IBM PC
After the commercial success of the Apple II and Commodore PET in the late 1970s, IBM began development of its own products. Here, their advertising department has defined the term "personal computer" used so successful that it is brought up to the present time in connection with the IBM brand.
On August 12, 1981, the first IBM PC was unveiled. He moved priced at the upper limit of standard PCs. In the basic configuration it could be purchased for 3,005 dollars or 1,565 dollars (without drives and monitor, but with TV connection ). In the maximum configuration with more memory and color graphics it was offered for $ 6,000. IBM used its then market leadership for ( mainframe ) computer systems and managed to make their IBM - PC was used as a workstation computer in numerous companies.
The unit was equipped with the Intel 8088 processor and had an 8- bit ISA bus system. The following models were equipped with processors of Intel. The one year before the 8088 processor ( 4.77 to 9.5 MHz clock, CPU internal word length of 16 bits; system data bus 8 bits) presented by Intel 8086 processor (6-12 MHz clock, CPU word length of 16 bit, system bus 16 bit) made sure that for the series, the abbreviation " x86 " established.
The IBM PC was from 1981 to 1995 exclusively distributed with the operating system from IBM, PC -DOS, which was licensed from Microsoft to IBM. The collaboration began in 1981, the company ended 1985. Both companies developed after the operating system separated further, but stayed on mutual compatibility. The operating system MS- DOS from Microsoft since there is only on computers, corresponding to those in the design of IBM, the "IBM PC compatible computers."
Home computers, Apple and IBM - compatible PCs
With TV-out and sound more devices came from the 1980s as a home computer on the market. The best selling models were the Commodore C64 and devices of the Amiga series, as well as various versions of the Atari ST.
In German-speaking the English word was personal ( in person) sometimes incorrectly associated with the German personnel ( workers, employees ) in the 1980s. A derivation of the personal computer towards a professional companies use appropriate equipment has been in this country therefore common. For medium power were in the media devices sometimes referred to as " [ not ] enough to the power of a personal computer approach " classified, although it was indeed also personal computers in such devices. Since the Amiga and the Atari ST series to home computer prices exceeded the IBM PC XT and AT power and partly used the housing form of professional equipment, the erroneous distinction disappeared at the end of the 1980s.
Since IBM no monopoly on the components used had ( with the exception of the BIOS), Compaq was able in 1983 to bring the first IBM PC compatible computers on the market. Especially in East Asia created company has a number of replicas, in Germany there were companies like Commodore and later Tailor. The so -developing market led by the competition to lower prices and increased innovation.
The numbers were comparable at the beginning still not nearly with those of today. The market situation in late 1983, according to professional microcomputer ( without home computer ):
Market positions of the six major provider of professional microphones by the end of 1983:
The American holiday shopping season 1984 personal computer played a significant role for the first time. However, both IBM and Apple had produced too many devices and complained in the spring of 1985 on a disappointing result. Many traders remained seated on the PCs, and customers complained that " they could not do much with the machines. " An Apple dealer gave even anyone who bought a computer, an Italian bike to.
Even Apple computers were partly rebuilt, but the company was able to maintain (with considerably shrunken market share). The Apple II line was discontinued at the beginning of the 1990s. Today, the Macintosh line is only produced. Apple and Sun (Unix) are the only two manufacturers who develop hardware and software ( operating system and application programs ) itself and also market together.
Most other manufacturers such as Commodore and Schneider, in the early 1990s largely disappeared from the market or turned back to other business areas (Atari ). The more recent PC models from IBM, as the PC 300GL remained largely unknown and went on the market with only the products of other manufacturers. Likewise the attempt by IBM to recapture the market with the Personal-System/2-Reihe and the operating system OS / 2.
In the private sector home computers and PC were first used to experiment, learn and play. Increasingly, they have been used in areas such as word processing, databases and spreadsheets and so found their way into daily operations.
Modern personal computer
The performance of personal computers increased steadily since their formation ( Moore's Law ). In addition to the tasks of word processing and spreadsheet the multimedia section to one of the main applications was. In order to meet the requirements of the latest PC games meet, there are so -called gaming PCs that are equipped with high computing power and high-performance graphics cards.
In modern PCs come today, regardless of the operating system, virtually without exception hardware based on the x86 architecture (also: IA -32 ) is used, based on the IBM Personal Computer goes back historically from 1981 and the so-called IBM - compatible enhancements. From the other computer architectures for stand-alone computers only a few models of Apple from the PowerPC era are in erwähnenswertem extent in use. However, these are no longer supported by Apple's Mac OS X operating system since version 10.6 because Apple now also relies on x86 processors.
As operating systems are used primarily based in addition to the market leading Microsoft Windows to Unix, especially Linux distributions. Also, the Apple operating system is a Unix variant, which is also officially certified in contrast to the various Linux distributions since version 10.5 the only more significant PC operating system as a UNIX system ( since the introduction of Mac OS X, see also List of operating systems).
Designs
According to the technical development, the types transformed with time.
The first IBM PC was literally a desktop computer, he and his contemporaries from other manufacturers had housing in landscape mode and stood on the work table. On them again stood the monitor with a screen diagonal of at that time only 10 to 13 inches. As this desktop PC to the time were a bit bigger and not just on the desk were always in the way, but also slowly increasing monitor models and more unfavorable were ergonomically on the computer, you went to standing next to the monitor PC cases in portrait about, so-called tower models. The latter differentiated in the port in Big Towers, Midi- Towers and more gradations. Depending on the height of the tower and preferences of the user many of today's personal computers are also under or beside the table.
Since the early 1980s, efforts were made parallel to the development of portable computers. Commodore released the SX64, which is still required as the later Kaypro and Osborne -1 models a power outlet. On battery operation was not to think mainly because these models were still equipped with built-in image tubes. Only with the availability of inexpensive LCD displays came first laptops on the market. These were then permanently reduced to the extent it allowed the technical level, which initially led to the class of notebooks, then in 2005 to the netbooks and the tablet computers.
Dissemination
The number of PCs sold worldwide has continued to decline in 2013, a total of about 316 million units have been sold, of which almost 26 million in Europe (more precisely: EMEA - the economic region, Europe, the Middle East and Africa, ). Total sales compared to 2012 decreased by approximately 10%. This decrease is due inter alia to the further spread of tablet computers and smartphones.
In the past, the majority of PCs sold was used as a workstation in business and management, but also many households possessed PCs.
Especially in emerging countries ( "emerging markets" ) have people today instead of a PC with Internet access as the first device more of a smartphone for communication and a tablet computer as a computer.
Environmental impact
Ever since around 2005 environmental impact caused by PCs are identified and explored. The environmental impacts are significant due to the high sales figures and a variety of pollutants in the production, they pollute the environment, in particular for production facilities and through the material and energy consumption. The area of computer science that deals with environmental aspects of PCs and computer hardware in general, is the Green IT.
Resource consumption
One study in 2003 found it takes 240 liters of fossil fuels for the production of a computer, including 17-inch CRT monitor. Assuming a total weight of the system - including CRT monitor - from around 24 kg of which is ten times its own weight. In addition, approximately 22 kg of chemicals and 1,500 kg of water are needed.
Power consumption
To present (as of 2013) to be able to operate his PC as sparingly as possible, the observance of certain norms of the industry recommends. For power supplies, this is now the " 80 -PLUS " certification in Bronze, Silver, Gold or Platinum by the ENERGY STAR compliance of the U.S. Environmental Protection Agency.
A single PC in Desktop version needed for a long time largely constant around 50 W of electrical power. This value remained about until the introduction of the Intel Pentium III processor in the late 1990s. In the following period, these values increased rapidly to well over 100 W for the processor alone and partly at 200 W for the entire computer. A turnaround occurred in 2004, when the processor manufacturer AMD started 64 for the first time previously used only in notebooks functions for dynamic modification of the processor clock for its AMD Athlon. Through this today available in all processors function, the power consumption is at least without a dedicated graphics card and without complex calculations like again.
Significant deviations occur when the processor is actually utilized, and a lot more when using a dedicated graphics card, which - already required W between 10 and 80 - is present even if just a normal desktop.
Laptops and notebooks that have to be mobile and are designed for battery power, try as sparingly as possible with the electric power to achieve the longest possible battery life. Here, depending on the speed demand and load factors between about 10 W and reaches well over 60 W ( eg for mobile 3D graphics ). The values are substantially constant over time; Improvements in battery technology are mainly placed in a reduction of the case and only small parts in an extension of the term. Also, industrial PCs often use laptop technology, which, however, due to less power consumption, but to refrain from moving parts in the shape of fans and to be able to increase the mechanical robustness.
The even smaller single-board computers, UMPCs or netbooks need some with less than 10 W or less electrical power, but here most concessions in computing power have to be made.
Due to the high resource utilization in the production, it does not make sense, alone with a view to energy saving to buy a fuel-efficient new device, as compared to the energy consumption in manufacture and disposal, energy consumption during use is comparatively low. The resulting new production by the additional energy consumption can - if that is possible at all in normal home use - are compensated only after several years due to the lower power consumption.
Applications
Elaborate calculations such as 3D images in computer games, image calculations of graphics programs or video editing to increase this value to up to 300 W. Powerful PCs with fast processors and multiple graphics cards can theoretically come under full load to well over 500W.
Disposal
Personal computers are composed of electronic components. You will be taken back to Germany after the electronic waste regulation from manufacturers to capture structures. Owners are committed to the devices separately from other waste to feed the recording points. The withdrawal is free of charge in Germany. Outdated, yet functional PCs or components can be passed on to hobbyists or needy - eg in the framework of the project Linux4Afrika. Often old devices are also illegally shipped to third world countries where, often neglecting work safety and environmental protection measures, the valuable metals are extracted and the remainder is disposed of in landfills.