Apple DOS

Apple DOS is the disk operating system used on Apple II computers from late 1978 through early 1983, when it was superseded by ProDOS. It had three major releases, DOS 3.1, DOS 3.2, and DOS 3.3, each followed by a minor bug fix release, though only the DOS 3.2 minor release received its own version number, 3.2.1, and the best known and most used version was DOS 3.3 in its 1980 and 1983 releases. Before DOS 3.1 was released, Apple users had to rely on audio cassette tapes for data storage and retrieval. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/