On This Day - 16th April

The Apple II debuted at the first West Coast Computer Faire in San Francisco, marking an important step in the development of the personal and home computer. Designed by Steve Wozniak and marketed by Steve Jobs, it was a complete, ready-to-use computer rather than simply an electronic kit for the hobbyist. Its 1 MHz MOS 6502 processor, built-in BASIC in ROM, colour graphics, sound, keyboard and expansion slots gave it capabilities that could be developed and extended by its users. It could also use an ordinary television as a display, helping keep the cost of entry relatively low.

Unlike many earlier microcomputers, the Apple II was designed from the outset to be useful beyond the electronics enthusiast. Its open expansion architecture encouraged the development of additional hardware, while its accessible programming environment encouraged users to create their own software. Disk storage, printers, modems and other peripherals subsequently expanded its capabilities, allowing the machine to move beyond simple programming and into applications such as word processing, spreadsheets, databases, education and business.

The Apple II became one of the most important early home and personal computers, particularly in the United States, where it found a substantial following in homes, schools and small businesses. Its success helped establish a market for both computer software and third-party hardware and demonstrated that a personal computer could become a general-purpose machine rather than merely a programming or electronics hobby. Alongside computers such as the Commodore PET and TRS-80, the Apple II helped turn the emerging microcomputer industry into a mass market.

Its influence is particularly significant when viewed alongside the later development of machines such as the Acorn Atom, Sinclair ZX81 and ZX Spectrum. Although these computers differed considerably in price, design and intended market, they all emerged from the expanding personal-computer revolution that the Apple II helped to establish. The Apple II therefore represents an important link in the transition from the experimental microcomputers of the 1970s to the affordable home computers that became commonplace during the 1980s.

Sinclair Research announced that it had sold one million home computers worldwide, claiming to be the first company to reach that milestone. The total comprised around 130,000 ZX80s, 750,000 ZX81s and 200,000 ZX Spectrums. Sinclair also estimated that a further 600,000 Sinclair computers had been manufactured under licence by Timex for the North American market. The company said production in Dundee had reached approximately one computer every four seconds.

ECC Publications launched Timex/Sinclair User, a new magazine aimed at owners of Timex/Sinclair computers in the United States. Based on the format of Britain's Sinclair User, the magazine covered reviews, projects, books and programming, with a first print run of 100,000 copies. ECC estimated that around 750,000 Timex/Sinclair machines were already in the United States and expected that figure to reach two million within a year.