I found a couple Dreamcast controllers at the local thrift store for 99 cents each. Has anyone ever modded these to work with the xbox for emulators or even mod them for PC use?

well i asked a few people if old controllers can work with the xbox and they said they have to have the right drivers to work other wise they wont as for the connecting a Dreamcast controller to a pc you need something like this
http://www.jandaman.com/games.mvc?p=pc3in1mjb&Category_code=PC ://http://www.jandaman.com/games.mvc?p...tegory_code=PC ://http://www.jandaman.com/games.mvc?p...tegory_code=PC
i know its sold out but its just to show you what you need as im not sure you can wire it to a usb cable un less you can then i am mistaken.

well the dreamcast controller uses the maple bus so its not that easy. there is a piece of hardware called the cthulu ( check this thread ) that allows you to connect your joystick to different consoles. ive been kicking around and idea about pic chips that would "emulate" the xbox controller protocol so i could have retro controllers with xbox usb ends.. much like this cthulu except xbox only