Home computer

The home computer emerged in 1977 through what historians would later call "the Trinity": three machines from three companies that transformed computing from a hobbyist pursuit into a consumer product. The Commodore PET, Apple II, and TRS-80 appeared within months of each other, each solving the same problem differently: how to make computers usable by ordinary people.

The adjacent possible required the microprocessor's maturation. By 1977, chips like the MOS 6502 and Zilog Z80 were cheap enough, capable enough, and available enough for mass production. Memory costs had fallen dramatically. And crucially, a generation of hobbyists—the people who had built Altair 8800s from kits—now understood what consumers needed: keyboards, displays, storage, and software that worked without soldering.

The Commodore PET debuted first, demonstrated at the January 1977 Consumer Electronics Show. Chuck Peddle, who had designed the 6502 processor, led the project at Commodore. The PET came fully assembled with 4 or 8 KB of memory, a built-in cassette tape drive for storage, and a distinctive "chiclet" keyboard. At $795, it targeted schools and small businesses.

The Apple II, designed by Steve Wozniak and marketed by Steve Jobs, shipped in June 1977 at $1,298. Its killer feature was color graphics—no other affordable computer could display them. The self-contained unit included electronics, keyboard, and power supply, with BASIC in permanent memory and a TV serving as the display. When the floppy disk drive arrived in 1978 and VisiCalc spreadsheet software in 1979, the Apple II became the first computer essential for business.

The TRS-80 launched in August 1977 through Radio Shack's nationwide retail network—a distribution channel no competitor could match. At $599.95, it was the cheapest of the Trinity. Tandy expected to sell a few hundred units; they sold 10,000 in the first month and over 100,000 within two years. By 1980, Tandy was selling three times as many computers as Apple.

The cascade from home computers was transformative. Software became a retail product. Computer magazines proliferated. Programming became a skill millions taught themselves. Bulletin board systems connected users over phone lines. And a generation grew up expecting computers to be personal, not shared—a mindset that shaped everything that followed.

Path dependence favored different machines for different niches. Apple II dominated education and small business. TRS-80 reached mass consumers through Radio Shack. Commodore pivoted to the low-cost market, eventually selling more computers than anyone with the VIC-20 and C64. The IBM PC, arriving in 1981, would eventually eclipse them all—but it built on the market these pioneers created.

By 1980, the term "personal computer" had largely replaced "home computer," signaling the technology's expansion from households to offices. But the fundamental insight of 1977 remained: computers weren't just for institutions anymore. The Trinity proved that ordinary people would buy, use, and love machines that let them compute for themselves.

By 2026, the smartphone in every pocket descends from these 1977 machines. The expectations they created—that computing should be personal, accessible, and affordable—became the foundation of the digital age.