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عنوان : 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 computational 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 in 1971 by Intel Corporation, was originally designed to be the computing and logical processor of calculators and watches. From its simple design modern microprocessors evolved
Microsoft ® Encarta ® Reference Library 2005. © 1993-2004 Microsoft Corporation. All rights reserved.
The Altair 8800, developed in 1975 by Micro Instrumentation Telemetry 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 Jobs and Stephen Wozniak 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 incorporated Apple Computer, Inc., the same year.

Microsoft ® Encarta ® Reference Library 2005. © 1993-2004 Microsoft Corporation. All rights reserved.
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, and an operating system developed by Microsoft Corporation became the dominant software running PCs.

A graphical user interface (GUI)—a visually appealing way to represent computer commands and data on the screen—was first developed in 1983 when Apple introduced the Lisa, but the new user interface did not gain widespread notice until 1984 with the introduction of the Apple Macintosh. The Macintosh GUI combined icons (pictures that represent files or programs) with windows (boxes that each contain an open file or program). A pointing device known as a mouse controlled information on the screen. 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 (see User Interface). Today, software available for IBM PCs and clones, as well as most other popular computer platforms, also feature a GUI.

Since the early 1970s, computing power has doubled about every 18 months due 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—or in combination with—conventional electronic computer circuitry. These technological advances, coupled with new methods for interconnecting computers, such as the proposed Internet2, an advanced Internet under development by universities, industry, and the government, promise to make PCs even more powerful and useful.

Microsoft ® Encarta ® Reference Library 2005