Desktop computer

Categories: Personal computers | History of computing

Image:Martin Ultima's Dell.jpg
Desktop computer with several common peripherals (Monitor, keyboard, mouse, speakers, microphone and a printer)

A desktop computer is an independent personal computer that is made especially for use on a desk in an office or home. The term is used mainly to distinguish this type of personal computer from portable computers and laptops, but also to distinguish other types of computers like the PDA, server or mainframe.

Desktops are currently the more affordable and most common computers, and are frequently used by businesses, schools, households and other organizations. Nearly all modern desktop computers are modular, meaning that the components can easily be replaced or upgraded. A desktop computer can also refer to a computer whose case is oriented horizontally (usually, the monitor is placed on top of the case). Such cases are called Desktops as opposed to Towers.

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History

Desktop Computers were vastly produced in the late 1970s and 1980s as there were no laptop or PDA computers available at the time. The first widely sold and successful desktop computer was the Apple II introduced in 1977 by Apple Computer. Also the TandyRS-80 computer which comprised a green phosphor 12" screen, an expansion box with 4k memory, a keyboard and a cassette. All this for only £695. Radio Shack, the American Tandy Corporation, put the TRS-80 up against Eniac and the Tandy beat the city block computer. In approx 1980 Tandy came out with the TRS-80 II, a 6000 risc chip machine which had the ability of voice recognition, multi-tasking, DVD via the 12" Philips discs and other processes etc which are just recently becoming available.

In 1981 IBM entered the desktop computer market with their IBM PC. Maybe the most important push to IBM compatibles over all other computers was because Albert Clark, an Air Force program manager who was faced with a growing government user base, sharing mainframe time, who were purchasing the various non-compatible home computers to replace their VT-100 dumb terminals. There were as many as 10 different brands that could all emulate a VT-100, but required different actions to boot up and run. Other users were purchasing home computers that could not, but needed to emulate a VT-100. Rather than have to justify a single brand of computer with proprietary software and hardware, he chose what, at that time, was arguably the most backward computer of its time. It had no sound card, monochrome screen with no graphics, and only a keyboard interface, but it was inexpensive and multiple manufacturers could legally produce them. He wrote the government specification for an “IBM compatible” computer for purchase across the US Department of Defense. Contracting officials did not take the compatibility issue seriously so Albert Clark had to approve the next 3 major specifications prior to release to industry for bidding. The eventual result was the purchase of several million IBM compatible personal computers all across the government which encouraged many of the government contractors to buy IBM compatibles “to be compatible with the government.” The result was that the “IBM compatible computers”, Intel processors, and Microsoft became the standard.

In the mid 1990s desktop computers were widely advertised for their amount of power available for graphics and multimedia. Studios, universities and governments prefer to use desktop computers today because they are more powerful and more expandable than a laptop computer.

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Hardware

The hardware in a desktop computer is modular, making it easy for someone with intermediate knowledge of a computer to modify one. The internal hardware of a basic desktop computer consists of RAM, CPU, a motherboard, a graphics card and a sound card as well as additional onboard cards for Ethernet and other ports.

Desktop computers usually have a separate monitor, the only modern exceptions being some Apple computers such as the iMacs and eMacs. User-input peripherals such as keyboards and mice are attached to the computer's ports, as well as other peripherals such as printers. Most of the functionality is contained within the case, but some components can be either either external or internal (such as various storage devices or modems). The case is often placed on or under the desk. Sometimes, it can be placed underneath the monitor depending on the size and shape.

Desktop computers are generally more affordable than notebook computers. This is because no extra effort is needed to miniaturize the components, or to manufacture components that use up less power.

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Components

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Ports

All desktop computers have ports which are used to plug external devices into the computer such as monitors, keyboards, printers and scanners.

  • USB - Used for the majority of peripherals
  • Ethernet - Used for networking and broadband Internet connections
  • Modem - Used for data access via a Telephone line (eg. dial-up Internet connections)
  • Headphone jack - Used for connecting sound devices
  • Serial - Used for connecting any device that uses a serial connector
  • Parallel - Used for connecting any device that uses a parallel connector
  • PS/2 - Used for computer mice and keyboards
  • Video (VGA) - Used for connecting a monitor / projector
  • Power - Used for connecting the power lead
  • FireWire/IEEE 1394 - Used for connecting external hard drives and camcorders
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All-in-one

All-in-one computers are desktop computers that combine the monitor into the same case as the CPU. The term, "all-in-one" was initially associated with Digital Equipment Corporation's VAX "all-in-one" software which provided a common menu to choose: email, spreadsheet, database, file system, etc. The "mouse" had not been invented yet so everything was driven by the keyboard. The original Macintosh introduced in 1984 by Apple Computer was one of the first all-in-one computers, In 1998 Apple released the iMac which was also an all-in-one computer. These types of desktop computers save desk space, but are limited when it comes to expansion to improve their capabilities. PC manufacturers have also released all-in-one computers such as Gateway. Some PC And refrigerator manufacturers have even included full featured PCs and monitors in refrigerators which could be considered all-in-one.

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See also

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