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Personal Computers
Personal Computer, machine capable of repetitively and quickly performing calculations and instructions. Designed to be used by a single person, a PC is smaller, less expensive, and easier to use than other classes of computers, such as supercomputers, mainframe computers, and workstations. However, it usually has less computational power. PCs have revolutionized entertainment, science, the media, art, medicine, education, and business because they provide computational abilities at a low cost to people with no extensive programming experience. PCs enable artists to envision and manipulate images. Musicians use them for learning, creating, and recording music. Businesses track finances and forecast company performance using PCs. Foreign correspondents can compose news stories on portable PCs, called laptops, and electronically submit these stories from remote locations. Many people work at home and communicate with fellow workers via their PCs in a practice known as telecommuting. PCs are also able to interface with worldwide communication networks, such as the Internet, and the graphics-based information database known as the World Wide Web to find information on any subject.
Parts of a Personal Computer
PCs consist of electronic circuitry called a microprocessor, such as the central processing unit (CPU), that directs logical and arithmetical functions and runs computer programs. A PC also has electronic memory to temporarily store programs and data and mass storage devices\'97such as hard, floppy, and compact disc (CD-ROM) drives\'97to permanently store programs and data. Information and commands are entered by the user via a keyboard or a pointing device called a mouse. Information from the PC is displayed on a video monitor or on a liquid crystal display (LCD) video screen, or it can be printed on laser, dot-matrix, or inkjet printer
History of the Personal Computer
In the mid-1940s, early computers were the size of houses and as expensive as battleships, but they had none of the power or ease of use that are common in modern PCs. The miniaturization of electronic circuitry and the invention of integrated circuits and microprocessors enabled computer makers to combine the essential elements of a computer onto tiny silicon computer chips, thereby increasing computer performance and decreasing cost. The first microprocessor, the Intel 4004, created by Intel Corporation, was originally designed to be the computing and logical processor of calculators and watches. From its simple design modern microprocessors evolved. Altair 8800 , developed by Micro Instruments Telementry Systems (MITS), is considered to be the first PC. The Altair was built from a kit and programmed by using switches. Information from the computer was displayed by light-emitting diodes on the front panel of the machine. The Altair appeared on the cover of Popular Electronics magazine in 1975 and inspired many computer enthusiasts who would later establish companies to produce computer hardware and software. American computer designers Steven JobsStephen Wozniak , working out of their garage, created the Apple II in 1977. The Apple II was one of the first PCs to incorporate a color video display and a keyboard that made the computer easy to use. Jobs and Wozniak later founded Apple Computer Corporation. In 1981 International Business Machines Corporation (IBM) introduced the IBM PC. It was designed with an open architecture that enabled other computer manufacturers to create similar machines, or clones, that could also run software designed for the IBM PC. The design of the IBM PC and its clones soon became the PC standard. The Apple Macintosh, developed in 1984, featured a graphical user interface (GUI)\'97a visually appealing way to represent computer commands and data on the screen. The Macintosh GUI combined icons (pictures that represent files or programs) with windows (boxes that each contain an open file or program). Information on the screen was controlled by a pointing device known as a mouse. Inspired by earlier work of computer scientists at Xerox Corporation, the Macintosh user interface made computers easy and fun to use and eliminated the need to type in complex commands 2. Today, software available for IMB PCs and clones also features a GUI.
During the last 20 years, computing power has doubled about every 18 months thanks to the creation of faster microprocessors, the incorporation of multiple microprocessor designs, and the development of new storage technologies. Ongoing research is focused on creating computers that use light and biological molecules instead of\'97or in combination with\'97conventional electronic computer circuitry. These technological advances, coupled with new methods for interconnecting computers, such as the World Wide Web, will make PCs even more powerful and useful.