I want to build a wonderswan/wonderswan color flashcart but someone tells me it would be too convoluted. However, I have a tendency to doubt his advice because: 1) He says GBC emulators are too much for the DS to handle, which sounds like a joke, and 2) There is already a very very scarcely produced Wonderswan flashcart in asia called the WonderMagic Color, though it ran through a printer port rather than USB.
I hear the WS series uses a mapper similar to the Gameboy and NES and they have flashcarts available so I don't know if its true that its impossible to make a WSC flashcart. I just want some advice as I may help make one available in limited numbers in the future, possibly with USB. Thanks!