Editing Atari 8-bit computers (section)

===Disk Operating System===
{{Main|Atari DOS}}

The standard Atari OS only contains low-level routines for accessing [[floppy disk]] drives. An extra layer, a [[disk operating system]], is required to assist in organizing [[file system]]-level disk access. [[Atari DOS]] has to be booted from floppy disk at every power-on or reset. Atari DOS is entirely menu-driven.

*DOS 1.0
*DOS 2.0S – Improved over DOS 1.0; became the standard for the 810 disk drive.
*DOS 3.0 – Came with 1050 drive. Uses a different disk format which is incompatible with DOS 2.0, making it unpopular.
*DOS 2.5 – Replaced DOS 3.0 with later 1050s. Functionally identical to DOS 2.0S, but able to read and write [[Atari DOS#Disk formats|enhanced density]] disks.
*DOS XE – Designed for the [[Atari XF551]] double-density drive.

[[Atari DOS#Third-party DOS programs|Third-party replacement DOSes]] were also available.