Here are key dates in the history of the personal computer, which took off with the release 25 years ago this Saturday of the IBM 5150:
January 1973: French high-tech firm Realisations d'Etudes Electroniques (R2E) releases a microprocessor-based Micral personal computer. The Micral did not gain worldwide momentum and was later modified to be IBM-compatible.
April 1976: The first Apple Computer is sold by Steve Jobs and Steve Wozniak, who started the business in a home garage in what is now Silicon Valley. Apple kept its technology proprietary.
April and August 1977: Apple Computer and Tandy Corp. release personal computer models in a period described by a California tech historian as "a heady time to be alive."
August 12, 1981: The IBM 5150 is unveiled to the public after a year's development. Powered by a Microsoft operating system, it is touted by IBM as "the computer for just about everyone who has ever wanted a personal system at the office, on the university campus or at home."
August 1982: Commodore Business Machines releases the Commodore 64, nicknamed the "breadbox" because of its shape. The machine joins Apple II, IBM PC, and the Atari 400/800 in the ranks of top competitors in the US market.
January 1983: Time magazine names the PC "Person of the Year" for 1982.
January 1983: The US National Science Foundation launches the first "TCP/IP" area network at a university, marking what some consider the technical genesis of the Internet.
March 1983: US firm Compaq introduces its version of the IBM PC, leading a wave of clones that drive down prices and igniting a true market among small-business owners and home users.
January 1984: Apple releases its first Macintosh model, notable for its use of on-screen icons which users can activate by clicking on a mouse.
November 1985: Microsoft adopts the mouse-icon idea in its first "Windows" release, a graphical interface that goes on to become the world's most popular computer operating system.
August 1991: The European Organization for Nuclear Research (CERN) particle physics laboratory, on the border between France and Switzerland, announces the World Wide Web project.
August 1995: Microsoft releases Windows 95, a completely revamped version of its operating system. More than a million copies are sold in the first four days after its release.
May 1998: Apple, back from the dead with Steve Jobs returning to the helm, announces the iMac -- the first all-in-one desktop containing the central computing unit inside the monitor.
Early 2000s: Computer chips get faster and more powerful as the industry fulfills "Moore's Law," which states that microprocessor performance will double every two years. Computing power that once took up rooms fits in mobile devices.
December 2004: IBM sells its PC unit to Chinese group Lenovo in a 1.75 billion dollar deal, says will focus on mainframe computers and business services.
