Wii7800 is a port of the ProSystem emulator developed by Greg Stanton. Additional changes developed by Ludovic Jacomme aka Zx-81 (PSP port), Leonis, and gdement.
To find out if a particular cartridge/ROM is compatible with Wii7800, please refer to the following page: Wii7800 Cartridge Compatibility List
This page contains a list of compatible ROMs by "hash code".