Duplo is a tool for dumping the ROM in some Game Boy Advance Video cartridges. It is a SLOT-1 homebrew for the DS that dumps the ROM in the SLOT-2 cartridge. It cannot dump any other type of ROM than those used in these Game Boy Advance Video cartridges. These use an undocumented mapper by Matrix Memory that has been partially reverse engineered for the purposes of this project. In the future, it may be possible to do more with this mapper.