St.7z

: The .7z extension indicates the file is compressed using the 7-Zip algorithm, which offers higher compression ratios than standard ZIP files.

: MAME can often read the .7z format directly, meaning users do not always need to extract the files into a subfolder.

In the world of retro gaming and emulation, "ST.7z" serves as a standard naming convention for the operating system files required to run Atari ST software on modern hardware. Because the Atari ST utilized proprietary chips, emulators require a digital copy of these roms to function.