Apple II

Apple II ("apple two", 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 a 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.

Despite the introduction of the Motorola 68000-based Macintosh in 1984, the Apple II series still reportedly accounted for 85% of the company's hardware sales in the first quarter of fiscal 1985. Apple continued to sell Apple II systems alongside the Macintosh until terminating the IIGS in December 1992 and the IIe in November 1993. The last II-series Apple in production, the IIe card for Macintoshes, was discontinued on October 15, 1993; having been one of the longest running mass-produced home computer series, the total Apple II sales of all of its models during its 16-year production run were about 6 million units (including about 1.25 million Apple IIGS models) with the peak occurring in 1983 when 1 million were sold.

Unlike preceding home microcomputers, the Apple II was sold as a finished consumer appliance rather than as a kit (unassembled or preassembled). Apple marketed the Apple II as a durable product, including a 1981 ad in which an Apple II survived a fire started when a cat belonging to one early user knocked over a lamp.

All the machines in the series, except the IIc, share similar overall design elements. The plastic case was designed to look more like a home appliance than a piece of electronic equipment, and the case can be opened without the use of tools. All models in the Apple II series have a built-in keyboard, with the exception of the IIGS which has a separate keyboard.

Apple IIs have color and high-resolution graphics modes, sound capabilities and a built-in BASIC programming language. The motherboard holds eight expansion slots and an array of random access memory (RAM) sockets that can hold up to 48 kilobytes. Over the course of the Apple II series' life, an enormous amount of first- and third-party hardware was made available to extend the capabilities of the machine. The IIc was designed as a compact, portable unit, not intended to be disassembled, and cannot use most of the expansion hardware sold for the other machines in the series.

The original Apple II has the operating system in ROM along with a BASIC variant called Integer BASIC. Apple eventually released Applesoft BASIC, a more advanced variant of the language which users can run instead of Integer BASIC. The Apple II series eventually supported over 1,500 software programs.