Personal computer

The term personal computer or PC has three meanings:

IBM's range of PCs that led to the use of the term - see IBM PC.
Any microcomputer - (mentioned here).
Any computer based on IBM's original specifications also known as IBM PC compatible.

The first generation of microcomputers were called just that, and only sold in small numbers to those able to (build them from kits or) operate them: engineers and accomplished hobbyists. The second generation micros were known as home computers, and are discussed in that section.

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 games, 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

Personal computers can be categorized by size and portability:

the desktop computer
the notebook or laptop
the PDA
the wearable computer

Most clases of PCs still follow the same basic IBM PC compatible design. This design makes them easily upgradable and standardized.

Motherboard

Main Article: PC motherboard

The motherboard is the primary circuit board for a computer. Most other computer components plug directly into the motherboard to allow them to exchange information. Motherboards usually hold a chipset, BIOS, CMOS, parallel port, PS/2 keyboard and mouse ports and expansion bays. Sometimes a secondary daughter board is plugged into the motherboard to provide more expansion bays and to cut down on size.

Central processing unit

Main Article: Central processing unit

The Central processing unit or CPU is the part of the computer that performs most of the calculations that make programs or Operating Systems run. The CPU plugs directly into the motherboard by one of many different types of sockets. Most IBM PC compatible computers use an x86-compatible processor made by Intel, AMD, VIA Technologies or Transmeta.

The hardware capabilities of personal computers can usually be extended by the addition of Expansion cards. The standard expansion bays for personal computers are ISA, PCI and AGP. A PC may also be upgraded by the addition of extra drives (CD-ROM, Hard drive, etc). Standard storage device interfaces are ATA, Serial ATA or SCSI.

Non-IBM compatible "personal computers"

Despite the overwhelming popularity of the personal computer, a number of non-IBM PC compatible microcomputers (sometimes also generically called Personal Computers) are still popular in niche uses. The leading alternative is Apple Computer's proprietary Power Macintosh platform, based on the PowerPC computer architecture, which is widely used for graphic design and related uses.

Further PC and PW (Personal Workstation) types through time: