Apple II

The Apple II was a very popular home/hobby computer line of the 1970s and 1980s, leading to the early success of the Apple Computer company. It was the successor to the hobby-kit Apple I. A later business-oriented Apple III computer failed to catch on, and thereafter Apple adopted different naming conventions for their computer lines than sticking Roman numerals after their company name, starting with the Lisa and continuing with their successful Macintosh line. (They would, however, sometimes return to Roman numerals for later product releases such as the Mac II and iPhone X.)

The original Apple II model started up in an assembly-language-based "monitor", and also had Integer BASIC in ROM, with data storage being handled with cassette tape. Adding on a disk drive caused the system to boot with Apple II DOS (much later replaced by ProDOS). With the Apple II+ model, the BASIC version in ROM was Applesoft II Floating Point BASIC instead. Later Apple II models included the IIe, IIc, and IIgs, extending the life of this computer line into the early 1990s before it was finally discontinued.