Fun trivia about the Xbox controller is that their design is heavily influenced by Sega's. The Xbox controller has the same face button layout as the Dreamcast's. And if you compare the Duke (original fat) controller to a Saturn/Genesis/Mega Drive 6-button controller, you can think of those black and white buttons as the former C and Z buttons.
Some consider the OG Xbox as a successor to the Dreamcast.
I prefer them to be exFAT.