Sega Genesis, aka Mega Drive for regions outside of North America, sound format created by the Genecyst emulator; contains video game audio data that was logged from the data sent to the YM2612 sound chip.

The GYM name comes from Genesis YM2612, which is the console's sound chip. By using the Genecyst emulator, users could log the audio data stream sent to the YN2612 sound chip into the GYM file. They could then play the GYM file back with an audio player to listen to the music. However, the .VGM format was later introduced as an improved version of the GYM format and replaced it. NOTE: The GYM format can be played by the Winamp program with the appropriate plugin.