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Found 4 file extension associations related to TOS and 4 file formats developed specifically for use with TOS.

Platform, operating system:  Other operating systems or devices icon Other operating systems or devices

Go to: TOS description

Developer: Atari, Inc.

Atari software list & details

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TOS picture

Atari, Inc. logoTOS

Developer / company: Atari

TOS (The Operating System or Tramiel Operating System) is the operating system of the Atari ST range of computers. This range includes the 520ST and 1040ST, their STF/M/FM and STE variants and the Mega ST/STE.

TOS structure:

  • Desktop - The main interface loaded after boot-up.
  • GEM - Graphics Environment Manager, licensed from Digital Research
  • AES - Application Environment Services
  • VDI - Virtual Device Interface (screen drivers only, other drivers loaded using GDOS)
  • GEMDOS - GEM Disk Operating System
  • BIOS - Basic Input/Output System
  • XBIOS - Xtended BIOS
  • Line-A - Low-level high-speed graphics calls. Obsolete
  • The following were extensions to TOS (loaded separately):
  • GDOS - Graphics Device Operation System
  • AHDI - Atari Hard Disk Interface (driver for Hard Drive)

Basic file extensions used by TOS:

  • ACC - Desktop accessory. Automatically loaded.
  • APP - Application (rarely encountered).
  • PRG - Executable program. Can be GEM programs.
  • TOS - TOS program that doesn't use GEM
  • TTP - TOS takes parameters

The TOS device or software seems to be old or discontinued.
Such programs or devices are no longer available and supported by their original developers, or are simply obsolete for their purpose. Sometimes companies offer limited support through their website.

TOS pictureTOS works with the following file extensions:

Note: You can click on any file extension link from the list below, to view its detailed information. The list of extensions used or otherwise associated with the application may not be complete, because many common file extensions on our website, such as jpg (pictures) or txt (text files), can be opened by a large number of applications, or are too general file format. However most, if not all directly associated file extensions should be listed with its appropriate program. Although its likely, that some file extensions may be missing from the list of associated file extensions with the application, yet they can be opened, be part of, or otherwise be associated with the program.

TOS default file extension associations

The most common file format used with the specific file extension

prg file icon.prg file extension is used for Program

Other file extensions or file formats developed for use with TOS

acc file icon.accacx file icon.acxhyp file icon.hyp

Common file extensions used by TOS

prg file icon.prg

Comparison table of actions that TOS can perform with each of its associated file type beta

This table might not contain all possible associated or supported file types or may contain incorrect data.
If you need more information please contact the developers of TOS (Atari, Inc.), or check out their product website.

File type \ Action


























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