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.

Changes:

– Lightgun support
– High score cartridge support
– Increased accuracy of Maria cycle timing, games now run at close to their intended speed (One on One, Tower Toppler, Summer Games, KLAX, Karateka, etc.)
– Increased compatibility for PAL games (Ballblazer, Commando, and Food Fight now work)
– Audio now sounds as it should regardless of frequency (PAL games and custom frame rates)
– Timers now properly take into consideration cycles generated via Maria and during WSYNC
– Changes to ProSystem database format
* Maria cycles are now enabled by default (option 0x1 now disables Maria, the opposite of before)
* Ability to adjust the lightgun crosshair offset per game
– All games now have Maria cycles and WSYNC enabled in the ProSystem database (with the exception of MIA)
– Console switch defaults updated to work with the majority of games
– Additions to debug output (Maria vs. CPU cycles, timer info, etc.)
– Other games improved by various changes
* Kung Fu Master no longer has the lines in the upper left corner of display and the Fuji logo appears as it should (if using BIOS)
* Midnight Mutants has less graphical glitches
* Summer Games has less graphical glitches
* Plutos has slightly less graphical glitches
– Fixed save/restore state issue for games that use RIOT timers.

http://wiibrew.org/wiki/Wii7800