Developed by: Atari
Launched: 1979

Atari DOS is the disk operating system used by the Atari 8-bit family of computers, which came integrated into the ROM.

Although the standard Atari Operating System had low-level routines for accessing floppy disk drives, a number of extensions to the operating system were added to organize disk access, known as the Disk Operating System (DOS).
These extensions contained the disk driver software and the "File Management System."

Like most DOS systems of the time, when the computer started up, the FMS was loaded into RAM from a floppy disk. This meant that at least 32K of additional RAM was required for the system to function with DOS loaded.

Unlike most other disk operating systems, the Atari DOS was entirely menu-driven.