Apple II

Apple II (stylized as apple ][) is a series of microcomputers manufactured by Apple Computer, Inc. from 1977 to 1993. The original Apple II model, which gave the series its name, was designed by Steve Wozniak and was first sold on June 10, 1977. Its success led to it being followed by the Apple II Plus, Apple IIe, Apple IIc, and Apple IIc Plus, with the 1983 IIe being the most popular. The name is trademarked with square brackets as Apple ][, then, beginning with the IIe, as Apple //.

The Apple II was a major advancement over its predecessor, the Apple I, in terms of ease of use, features, and expandability. It became one of several recognizable and successful computers throughout the 1980s, although this was mainly limited to the US. It was aggressively marketed through volume discounts and manufacturing arrangements to educational institutions, which made it the first computer in widespread use in American secondary schools, displacing the early leader Commodore PET. The effort to develop educational and business software for the Apple II, including the 1979 release of the popular VisiCalc spreadsheet, made the computer especially popular with business users and families.

The Apple II computers are based on the 6502 8-bit processor and can display text and two resolutions of color graphics. A software-controlled speaker provides one channel of low-fidelity audio. A model with more advanced graphics and sound, and with a 65C816 16-bit processor, the Apple IIGS, was added in 1986. It remained compatible with earlier Apple II models, but the IIGS has more in common with mid-1980s systems like the Atari ST, Amiga, and Acorn Archimedes.