History
A personal computer is an inexpensive microcomputer, originally designed to be used by only one person at a time, and which is IBM PC compatible - (though in common usage it may sometimes refer to non-compatible machines).
The earliest known use of the term was in New Scientist magazine in 1964, in a series of articles called "The World in 1984". In "The Banishment of Paper Work," Arthur L. Samuel of IBM's Watson Research Center writes, "While it will be entirely feasible to obtain an education at home, via one's own personal computer, human nature will not have changed."
The first generation of microcomputers that started to appear in the 1970s (see home computers) were less powerful and in some ways less versatile than business computers of the day (but in other ways more versatile, in terms of built-in sound and graphics capabilities), and were generally used by computer enthusiasts for learning to program, for running simple office/productivity applications, for electronics interfacing, and/or gamess, as well as for accessing BBS's, general online services such as CompuServe, The Source, or Genie, or platform-specific services such as QuantumLink (US) or Compunet (UK).
It was the launch of the VisiCalc spreadsheet, initially for the Apple II and later for the Atari 8-bit family, Commodore PET, and IBM PC that became the "killer app" that turned the microcomputer into a business tool. Later, Lotus 1-2-3, a combined spreadsheet (partly based on VisiCalc), presentation graphics, and simple database application, became the PCs own killer app. Good wordprocessor programs also appeared for many home computers. The low cost of personal computers led to great popularity in the home and business markets during the 1980s. In 1982, Time magazine named the personal computer its Man of the Year.
During the 1990s, the power of personal computers increased radically, blurring the formerly sharp distinction between personal computers and multi-user computers such as mainframes. Today higher-end computers often distinguish themselves from personal computers by greater reliability or greater ability to multitask, rather than by straight CPU power.
Architecture and expansion
Most modern personal computers use the IBM PC compatible hardware architecture, using x86-compatible processors made by Intel, AMD, or Cyrix. The hardware capabilities of personal computers can usually be extended by the addition of Expansion cards.
With regard to portability we can distinguish:
