The Personal Computer

Origins

The personal computer emerged from the microprocessor revolution. Intel’s 4004 (1971) and 8080 (1974) put a computer’s central processing unit on a single chip. Hobbyists recognized the possibility of building affordable computers for individual use. The Altair 8800, sold as a kit in 1975, launched the personal computer industry.

The Altair was a bare-bones machine requiring assembly and programming in machine language. Two Harvard students, Bill Gates and Paul Allen, wrote a BASIC interpreter for it, founding Microsoft. Steve Wozniak built a more complete machine, the Apple I, selling it through the Homebrew Computer Club. The Apple II (1977), with color graphics and a disk drive, became the first successful mass-market personal computer.

IBM’s entry (1981) legitimized personal computing for business. The IBM PC’s open architecture—using standard components and a separately licensed operating system (Microsoft’s DOS)—enabled clones and created the PC industry. By the mid-1980s, personal computers had become standard business equipment; by the 1990s, home computers were commonplace.

Structure & Function

The personal computer industry developed through layers: hardware (computers, peripherals), operating systems (DOS, Windows, MacOS), applications software, and eventually internet services. Each layer had its dominant players and its challengers. Microsoft’s control of the operating system layer proved most durable; hardware became increasingly commoditized.

Software transformed from custom development to packaged products. VisiCalc, the first spreadsheet (1979), demonstrated that software could drive hardware sales. Word processors, databases, and desktop publishing applications followed. Software companies—Microsoft, Lotus, Adobe—became industry giants.

Historical Significance

The personal computer democratized computing. Tasks that once required mainframes and specialists—word processing, financial modeling, database management—became accessible to individuals and small organizations. White-collar work was transformed; typing pools disappeared as professionals created their own documents. Entrepreneurship was enabled as startups could afford capable computing systems.

The cultural impact extended beyond productivity. Personal computers enabled new forms of creativity—desktop publishing, digital music, amateur video production. Computer games created a new entertainment medium. And when the internet connected personal computers into a global network, the digital revolution accelerated dramatically.