Editing Atari DOS (section)

{{About|the operating system of the Atari 8-bit computers|the Atari ST's operating system|Atari TOS|the MS-DOS compatible operating system of the Atari Portfolio|DIP DOS}}
{{Redirect|MyDOS|the similarly pronounced Microsoft operating system|MIDAS (operating system){{!}}MIDAS}}
{{Redirect|RealDOS|the similarly named successor to Multiuser DOS|IMS REAL/32}}
{{Redirect|Turbo-DOS|the CP/M-compatible operating system|Software 2000 TurboDOS}}

{{More citations needed|date=March 2020}}

{{Infobox OS
|name = Atari DOS
|logo =
|screenshot = Ataridos-2.5.PNG
|caption = Atari DOS version 2.5, main menu
|developer = [[Atari, Inc.]], [[Atari Corporation]]
|source_model = [[Closed source]]
|kernel_type =
|supported_platforms = [[Atari 8-bit computers]]
|ui = Menu
|family =
|released = {{Start date and age|1979}}
|latest_release_version = XE 1.0
|latest_release_date = {{Start date and age|1987}}
|latest_test_version =
|latest_test_date =
|marketing_target =
|programmed_in =
|prog_language =
|language = [[English language|English]]
|updatemodel =
|package_manager =
|working_state = Discontinued
|license = [[Proprietary software|Proprietary]] [[EULA]]
|website =
}}

'''Atari DOS''' is the [[disk operating system]] used with the [[Atari 8-bit computers]]. [[Operating system]] extensions loaded into memory were required in order for an Atari computer to manage files stored on a [[Disk storage|disk drive]]. These extensions to the operating system added the disk handler and other file management features.

{{anchor|FMS}}The most important extension is the disk handler. In Atari DOS 2.0, this was the '''File Management System''' ('''FMS'''), an implementation of a [[file system]] loaded from a [[floppy disk]]. This meant at least an additional {{nowrap|32 KB}} [[random-access memory|RAM]] was needed to run with DOS loaded.