Apple DOS
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Beneathappledos.jpg
Apple DOS refers to operating systems for the Apple II series of microcomputers from 1978 through 1982. Also known simply as DOS 3.x, Apple DOS had three important versions: DOS 3.1, DOS 3.2, and DOS 3.3. The last of these is the best-known and most-used version.
Apple DOS 3.1, which was the first disk-based operating system for any Apple computer, was released in 1978 for the Apple II. DOS 1 and DOS 2 were purely internal development versions; DOS 3.0 was never publicly released either as it had some remaining bugs. DOS 3.1 was largely written by Steve Wozniak, Randy Wigginton, and outside contractor Paul Laughton and was closely tied to the Integer BASIC programming language. It lacked any sort of official documentation from Apple, much to the dismay of many programmers.
Apple DOS 3.2 was released in 1979 to reflect major changes in computer booting methods that were built into the successor of the Apple II, the Apple II Plus. Instead of the original Integer BASIC, the newer AppleSoft BASIC was written into the ROM of the II+. Also, the new ROM had an updated computer reset function, which started automatically when the II+ was powered up.
Apple DOS 3.3 was released in 1980. DOS 3.3 improved various functions of DOS 3.2, while also allowing for large gains in available floppy disk storage without requiring different drive hardware. Unfortunately, this had the side effect of making it difficult to read disks formatted in DOS 3.2. DOS 3.3 also improved ability to switch between the old Integer BASIC and the newer AppleSoft BASIC if the user had a "Language Card" memory expansion.
Apple DOS could only read floppy disks running in a Disk II disk drive and could not access hard disk drives, virtual RAM drives, or 3.5-inch floppy disk drives.
The Apple DOS was entirely replaced by ProDOS in 1983. All the Apple computers from the Apple II Plus onward can run both DOS 3.3 and ProDOS, the Apple II Plus requiring a "Language Card" memory expansion to use ProDOS; the Apple //e and later models had built-in Language Card hardware, and so could run ProDOS out of the box. ProDOS included software to copy files from Apple DOS disks. However many people who had no need for the improvments of ProDOS continued using Apple DOS or one of its clones long after 1983.
References
- Worth, Don; Lechner, Pieter. Beneath Apple DOS. Reseda, CA: Quality Software, 1981.
External link
- Apple II History: DOS (http://apple2history.org/history/ah14.html)de:Apple DOS