ATP File

What are ATP files and how to open them

Are you having problems opening an ATP file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your ATP files.

What is an ATP file?

An .ATP file is an Atari 8-bit Protected Disk Image file.

An Atari Protected Disk Image is a disk‐image format for Atari 8-bit floppy disks, designed to store exact digital copies of disks including their copy-protection, irregular sector layouts, and error marks. It was developed by the ATP Working Group and published as "ATP Version 1.6" on April 11, 2004. It's used for archival preservation of commercial disks that cannot be accurately represented by simpler image formats.

Files are created by specialized disk-dumping tools that read protected Atari disks - reading raw sector data and protection metadata - and write out an ATP image that preserves bad sectors, timing anomalies, and other nonstandard disk features. Such images are typically used with emulation or preservation software that can interpret the protection data faithfully for exact restoration.

An ATP image file can be recognized by its signature: it begins with the ASCII letters "FROM" at the very start (offset 0), and contains "ATP1" starting at byte offset 8.

How to open ATP files

Important: Different programs may use files with the ATP file extension for different purposes, so unless you are sure which format your ATP file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested seven different ATP openers which you will find listed below.

Last updated: August 22, 2026

Various apps that use files with this extension

These apps are known to open certain types of ATP files. Remember, different programs may use ATP files for different purposes, so you may need to try out a few of them to be able to open your specific file.

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File.org helps thousands of users every day, and we would love to hear from you if you have additional information about ATP file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.