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Desktop computer

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A stylized illustration of a desktop personal computer

A desktop computer is a personal computer (PC) in a form intended for regular use at a single location, as opposed to a mobile laptop or portable computer. Prior to the wide spread of microprocessors, a computer that could fit on a desk was considered remarkably small. Desktop computers come in a variety of types ranging from large vertical tower cases to small form factor models that can be tucked behind an LCD monitor. "Desktop" can also indicate a horizontally-oriented computer case usually intended to have the display screen placed on top to save space on the desk top. Most modern desktop computers have separate screens and keyboards. Tower cases are desktop cases in the former sense, though not in the latter. Cases intended for home theater PC systems are usually considered to be desktop cases in both senses, regardless of orientation and placement.

History

HP 9830 was an early desktop computer with printer

Early computers took the space of a room. Minicomputers generally fit into one or a few refrigerator sized racks. It was not until the 1970s when computers such as the HP 9800 series desktop computers were fully programmable computers that fit entirely on top of a desk. The first large calculators were introduced in 1971, leading to a model programmable in BASIC in 1972. They used a smaller version of a minicomputer design based on ROM memory and had small one-line LED alphanumeric displays. They could draw computer graphics with a plotter. The Wang 2200 of 1973 had a full-size CRT and cassette tape storage. The IBM 5100 in 1975 had a small CRT display and could be programmed in BASIC and APL. These were generally expensive specialized computers sold for business or scientific uses. By the late 1970s and 1980s personal computers such as the Apple II series and the IBM Personal Computer used standard processors to reduce cost to put a complete computer on top of a desk with a separate monitor. These would find uses in the home as well as in business and industry, and later incorporate graphic user interfaces and powerful networked operating systems such as Mac and Windows

All-in-One

The iMac G4 is an example of an all-in-one desktop computer

All-in-One computers are desktop computers that combine the monitor into the same case as the CPU. Apple has manufactured several popular examples of all-in-one computers, such as the original Macintosh of the mid-1980s and the iMac of the late 1990s and 2000s. Some older 8-bit computers, such as the Commodore PET 2001 or Kaypro II, also fit into this category. All-in-One PCs are typically more portable than other desktop PCs and many have been built with carrying handles integrated into the case. They can simply be unplugged and transported to a new location.

Like laptops, All-in-One desktop computers are characterized by a comparative lack of upgradeability or hardware customization, as internal hardware is often placed in the back of the visual display unit. Furthermore, in the case of the iMac line since 2002, the CPU and other internal hardware units are, more or less, permanently glued to the motherboard due to space constraints.

However, latest models of the All In One Computer have changed their approach this issue. Many of the current offerings, like the Handii myFace and others, are using standard off-the-shelf components and are designing upgrade convenience into their products.

Comparison with laptops

Desktops have the advantage over laptops that the spare parts and extensions tend to be standardized, resulting in lower prices and greater availability. For example, the form factor of the motherboard is standardized, like the ATX form factor. Desktops have several standardized expansion slots, like Conventional PCI or PCI express, while laptops only tend to have one mini PCI slot and one PC card slot (or ExpressCard slot). This means that a desktop can be customized and upgraded to a greater extent than laptops. Procedures for (dis-)assembly of desktops tend to be simple and standardized to a great extent too. This tends not to be the case for laptops, though adding or replacing some parts, like the optical drive, rechargeable battery, hard disk, and adding an extra memory module is often quite simple.

Another advantage of desktop is, that (apart from environmental concerns) power consumption is not as critical as in laptop computers because the desktop is powered from the wall socket. Desktop computers also provides more space for heat to escape. The two large microprocessor manufacturers Intel and AMD develop special CPUs for mobile computers (i.e. laptops) that consume less power and lower heat, but with lower performance levels.

Health effects of desktop computers

Carelessly-arranged computer screens and keyboard can lead to ergonomics problems such as eyestrain and repetitive strain injuries while using a keyboard for long periods. The height of a standard desktop is not recommended for keyboard use, and stacking the monitor on the case aggravates posture problems.

Average selling price

For Microsoft Windows systems, the average selling price (ASP) showed a decline in 2008/2009, possibly due to low-cost Netbooks, drawing $569 at U.S. retail in August 2008. In 2009, ASP had further fallen to $533 by January.[1]

See also

References