The is a legacy audio driver associated with sound cards that were manufactured by Crystal Semiconductor (later acquired by Cirrus Logic). Specifically, it refers to a game port feature on older sound cards, which was commonly used for connecting MIDI devices, joysticks, and other gaming peripherals.

In the past, many sound cards, such as the Crystal SoundFusion series, included a game port interface that allowed users to connect devices like gamepads, joysticks, and MIDI keyboards. This was a common feature on PCs before the USB interface became standard for gaming peripherals.

The is the software that enables this functionality on a Windows PC. The driver allows the game port hardware to be recognized and used by applications, such as games or MIDI software, that support it.