I believe this was even more common on the SNES. The most well-known example is the Super FX chip, which was used in Star Fox and Yoshi's Island among others, b

I believe this was even more common on the SNES. The most well-known example is the Super FX chip, which was used in Star Fox and Yoshi's Island among others, but there were actually a ton of these things: https://en.wikipedia.org/wiki/List_of_Super_NES_enhancement_chips https://en.wikipedia.org/wiki/List_of_Super_NES_enhancement_...