i have a bunch of extra nintendo ds game cartriges that i've beaten the game on and are not worth the trade in/resell value at the local game store. I want to build my own ds flashcart(first on the ds, then hopefully getting the 3ds to read it) where can i find the info/tools to do this if it is even possible(not sure if it is at all because of how ds carts are built) Not saying i need to use my old ds cartriges(probably won't work anyway) but they may serve well as a case/ spare parts for my flash cart.