A 10.5MHz or 21MHz (depending on version) RISC co-processor chip present inside the cartridge of some of the more graphically enhanced SNES games. StarFox and Yoshi's Island are the most well-known games that featured this chip. The SuperFX chip enabled advanced (for its time) polygon and 3D graphics on the SNES. Emulation of this chip in emulators such as SNES9x allowed previously un-emulatable games to work.