What is an ACX file? An ACX file is a program written for Atari ST, a line of Atari computers from the 1980s. It may be a game or other type of application, such as a word processor or graphics editor. It is an executable file that a user can run on a computer with Atari ST emulation software.

More Information Atari introduced the Atari ST line in 1985 and released several ST models, including 520ST and 1040ST. However, Atari discontinued the Atari ST line in 1993. Retro computing enthusiasts utilize emulation software to run applications and play games on their modern computers. For example, a nostalgic computer user who enjoyed the Atari 1040ST computer from 1986 may install the Gemulator on their application to run a game saved as an ACX file.