beautiful wallpapers hd download: Beautiful Desktop Wallpaper

Thursday, 1 August 2013

Beautiful Desktop Wallpaper

Beautiful Desktop Wallpaper Biography

source(google.com.pk)

A desktop computer is a personal computer in a form intended for regular use at a single location, as opposed to a mobile laptop or portable computer. Early desktop computers are designed to lie flat on the desk, while modern towers stand upright. Most modern desktop computers have separate screens and keyboards.

Prior to the widespread use of microprocessors, a computer that could fit on a desk was considered remarkably small. Early personal computers, like the IBM PC, were "desktop" machines, with a horizontally oriented computer case, usually intended to have the display screen placed on top to save space on the desktop. In modern usage the word "desktop" usually refers to tower cases that are in fact more often located on the floor under the desk than on a desk.

Technically speaking desktop and tower computers are two different styles of computer case that use desk space in varying ways. Cases intended for home theater PC systems are usually considered to be desktop cases in both senses, regardless of orientation and placement.Early computers took up 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 very first large "programmable calculators/computers" (machines lacking keyboards for text input) were marketed in the second half of the 1960s, starting with Programma 101 (1965) and HP 9100 (1968). More desktop models were introduced in 1971, leading to a model programmable in BASIC in 1972. They used a smaller version of a minicomputer design based on read-only memory (ROM) and had small one-line LED alphanumeric displays. They could draw computer graphics with a plotter. The Wang 2200 of 1973 led operating systems such as Mac (Macintosh) and Windows.An all-in-one PC integrates the system's internal components into the same case as the display, allowing for easier portability and a smaller footprint, especially on designs using flat panel displays. Some recent all-in-one models also include touchscreen displays.

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. This form factor was popular during the mid-1980s for computers intended for professional use such as the Kaypro II, Commodore PET, Osborne 1, TRS-80 Model II and Compaq Portable. Other manufacturers like Commodore and Atari included the computer parts into the keyboard instead of the monitor in some of their models.

Like laptops, some all-in-one desktop computers are characterized by an inability to customize or upgrade its internal components, as internal hardware is often placed in the back of the unit. Furthermore, in the case of the iMac line since 2002, the CPU and other internal hardware units may also be permanently attached to the motherboard due to space constraints.

However, newer models of all-in-one computers have changed their approach to this issue. Many of the current manufacturers are using standard off-the-shelf components and are designing upgrade convenience into their products.