Apple III(1980)

歴史的背景

The Apple III (often rendered as Apple ///) is a business-oriented personal computer intended as the successor to the Apple II series, but largely considered a failure in the market. The system was announced on May 19, 1980, and released in late November that year. Serious stability issues required a design overhaul and a recall of the first 14,000 machines produced. The Apple III was formally reintroduced on November 9, 1981. The Apple III was designed to be a business computer and an eventual successor for the Apple II. While the Apple II contributed to the inspirations of several important business products, such as VisiCalc, Multiplan and Apple Writer, the computer's hardware architecture, operating system and developer environment were limited. The Apple III addressed these weaknesses. According to Steve Wozniak, VisiCalc and Disk II had caused the Apple II's popularity, with 90% of sales going to businesses as opposed to the hobbyists that were its original market. Once the logic board design flaws were discovered, a newer logic board design was produced – which included a lower power requirement, wider traces and better designed chip sockets. The $3,495 U.S. revised model also included 256 KB RAM as a standard configuration. The 14,000 units of the original Apple III sold were returned and replaced with the entirely new revised model. The Apple III Plus was introduced in December 1983 at a price of $2,995 U.S. This newer version included a built-in clock, video interlacing, standardized rear port connectors, 256K RAM as standard, and a re-designed keyboard. The keyboard was designed in the style of the earlier beige Apple IIe. Owners of the earlier Apple III could obtain the newer logic board as a service replacement. A keyboard upgrade kit, dubbed "Apple III Plus upgrade kit" was also made available – which included the keyboard, cover, keyboard encoder ROM and logo replacements.