Apple DOS

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Apple DOS

Apple computer running a Hello World program
Developer	Apple Computer
Written in	Assembly[1]
OS family	Apple DOS
Working state	Discontinued
Source model	Closed source
Initial release	1978; 46 years ago (1978)
Latest release	3.3 / 1980; 44 years ago (1980)
Kernel type	Monolithic kernel
License	Apple Software License Agreement

Apple DOS is the family of disk operating systems for the Apple II series of microcomputers from late 1978 through early 1983. It was superseded by ProDOS in 1983. Apple DOS has three major releases: DOS 3.1, DOS 3.2, and DOS 3.3; each one of these three releases was followed by a second, minor "bug-fix" release, but only in the case of Apple DOS 3.2 did that minor release receive its own version number, Apple DOS 3.2.1. The best-known and most-used version is Apple DOS 3.3 in the 1980 and 1983 releases. Prior to the release of Apple DOS 3.1, Apple users had to rely on audio cassette tapes for data storage and retrieval.