Personal computer

Lore & Background

In the history of computing, early experimental machines could be operated by a single attendant. For example, ENIAC which became operational in 1946 could be run by a single, albeit highly trained, person. This mode pre-dated the batch programming, or time-sharing modes with multiple users connected through terminals to mainframe computers. Computers intended for laboratory, instrumentation, or engineering purposes were built, and could be operated by one person in an interactive fashion.

Examples include such systems as the Bendix G15 and LGP-30 of 1956, and the Soviet MIR series of computers developed from 1965 to 1969. By the early 1970s, people in academic or research institutions had the opportunity for single-person use of a computer system in interactive mode for extended durations, although these systems would still have been too expensive to be owned by a single person. The personal computer was made possible by major advances in semiconductor technology. In 1959, the silicon integrated circuit (IC) chip was developed by Robert Noyce at Fairchild Semiconductor, and the metal–oxide–semiconductor (MOS) transistor was developed by Mohamed Atalla and Dawon Kahng at Bell Labs.

1960s

The MOS integrated circuit was commercialized by RCA in 1964, and then the silicon-gate MOS integrated circuit was developed by Federico Faggin at Fairchild in 1968. Faggin later used silicon-gate MOS technology to develop the first single-chip microprocessor, the Intel 4004, in 1971. The first microcomputers, based on microprocessors, were developed during the early 1970s.

Widespread commercial availability of microprocessors, from the mid-1970s onwards, made computers cheap enough for small businesses and individuals to own. In what was later to be called the Mother of All Demos, SRI researcher Douglas Engelbart in 1968 gave a preview of features that would later become staples of personal computers: e-mail, hypertext, word processing, video conferencing, and the mouse. The demonstration required technical support staff and a mainframe time-sharing computer that were far too costly for individual business use at the time. Early personal computers—generally called microcomputers—were often sold in a kit form and in limited volumes, and were of interest mostly to hobbyists and technicians.

From Silicon to Single-User Machines

The personal computer's story begins not in a garage but in semiconductor laboratories. These advances transformed computing from a realm of massive, expensive mainframes into something a single person could operate. By the early 1970s, academic and research settings offered single-person interactive access, though ownership by an individual remained financially out of reach.

The Hobbyist Decade and the Mother of All Demos

The 1970s marked the era when computers first became tangible objects for ordinary people, though the experience was far from polished. Early microcomputers were frequently sold as kits in small quantities, appealing primarily to hobbyists and technicians.

Programming meant flipping toggle switches to enter instructions, and results appeared as patterns of glowing front-panel lamps. Making these machines genuinely useful required bolting on peripherals—keyboards, displays, disk drives, printers. The irony was that his demonstration depended on a mainframe time-sharing system and support staff, far beyond any individual's budget.

Wintel, Mac, and the Platform Wars

Since the early 1990s, the personal computer market has been overwhelmingly defined by a single pairing: Microsoft operating systems, beginning with MS-DOS and evolving into Windows, running on Intel x86-based processors. This combination, colloquially dubbed Wintel, became so dominant that the word "PC" in common usage now almost exclusively refers to a Windows-based machine, even when the underlying chip is ARM rather than x86. Software publishers routinely label their products "for PC," cementing the association.

Apple's Mac platform, running macOS, and free open-source Unix-like systems such as Linux and its derivative ChromeOS hold minority market shares. Before the 1990s, the competitive landscape was broader, with the Amiga, Atari ST, and Japan's PC-98 line all carving out meaningful audiences. The terminology itself has caused confusion: while "PC" originally described any personal computer regardless of brand, the IBM Personal Computer's use of the name in its model designation led many to treat it as a brand.

Software Freedom and the End-User Revolution

In the 1960s, institutional and corporate computer owners were essentially forced to write their own programs to accomplish any useful task. The personal computer shattered that constraint. Today, the vast majority of end users simply install commercial applications or free-of-charge freeware—often built on closed, proprietary codebases—or they turn to free and open-source software whose source code is publicly available. Software is delivered in ready-to-run binary form, and it is typically developed and distributed by companies entirely independent of the hardware or operating system manufacturer.

This independence stands in sharp contrast to mobile systems, where software is often restricted to a manufacturer-supported channel and end-user program development may be actively discouraged. While practically no personal computer user needs to write code to get work done, the ability to develop one's own applications remains fully feasible. The shift from a world where computing meant writing programs by hand to one where word processing, web browsing, e-mail, spreadsheets, file management, and video calling are off-the-shelf activities represents one of the most profound changes in how people interact with technology.

Reader's Guide

Institutional or corporate computer owners in the 1960s had to write their own programs to do any useful work with computers. While personal computer users may develop their own applications, these systems most frequently run commercial or free-of-charge software ("freeware"), which commonly has closed source (proprietary) codebases; or free and open-source software, where the source code is made freely available. Software for end-users is typically provided in binary (ready-to-run) form.

Software for personal computers is typically developed and distributed independently from the hardware or operating system manufacturers. Practically all personal computer users no longer need to create programs themselves to make any use of a personal computer, although end-user programming is still feasible. This contrasts with mobile systems, where software is often available only through a manufacturer-supported channel and end-user program development may be discouraged by lack of support by the manufacturer.

Since the early 1990s, Microsoft operating systems (first with MS-DOS and then with Windows) and CPUs based on Intel's x86 architecture – collectively called Wintel – have dominated the personal computer market, and today the term PC normally refers to the ubiquitous Wintel platform, or to Windows PCs in general (including those running ARM chips), to the point where software for Windows is marketed as "for PC". Alternatives to Windows occupy a minority share of the market; these include the Mac platform from Apple (running the macOS operating system), and free and open-source, Unix-like operating systems, such as Linux (including the Linux-derived ChromeOS). Other notable platforms until the 1990s were the Amiga, Atari ST, and the PC-98 line.