Known Issues

  • High Score cartridge is only compatible with NTSC games.


To install Wii7800, simply extract the zip file directly to your SD card (retain the hierarchical structure exactly).

Cartridge images should be placed in the roms directory (/wii7800/roms). (Zip files are supported)

Wii7800 does support loading of the Atari 7800 BIOS, although it isn't necessary. If you wish to use the BIOS, simply place the NTSC and PAL BIOS files in the (/wii7800) directory. The NTSC file must be named, "7800.rom", while the PAL file must be named, "7800pal.rom".

Lightgun Accuracy, etc.

The crosshair for the Wii7800 emulator is not perfect. For example you may be pointing at something and your shot may register to the right or left. This is due to the way the 7800 handles hit detection for lightgun games. It only checks for a hit every 7 CPU cycles. There are 330 cycles for the visible portion of each frame. Thus, there are only ~47 hit points for each scanline. So, the crosshair at best gets you in approximately the right area, and if you miss you need to adjust based on where the shot shows up on the screen (exactly how you do it when there is no crosshair).

Cartridge/ROM Compatibility

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".


Wii7800 menu

    +       Action
  /     /   or     /   or     /   or   Scroll through the Menu
  /     /   or     /   or     /   or   Page through the Menu
    or       Select menu item
    or       Previous menu
        Exit to Homebrew channel

In-game (Joystick)

    +       Action
      or     or   Move
None None     Dual analog (if enabled)
    or       Fire 1
    or       Fire 2
None None   or     Pause
        Left Difficulty (if enabled)
        Right Difficulty (if enabled)
        Display Wii7800 menu (see above)

In-game (Lightgun)

  or   Fire
  Display Wii7800 menu (see above)


Special thanks

  • munky6 ~ Lead tester
  • Curt Vendel ~ Granting permission to use the High Score ROM
  • GroovyBee ~ Technical assistance
  • mimo ~ Testing
  • wilsoff ~ Icon
  • Tantric/eke-eke ~ Audio code example
  • Tantric ~ Huge improvements to the SDL
  • Team Twiizers ~ For enabling homebrew


0.4 - November 16, 2019

  • Reworked audio integration (resolves audio clipping and popping)
  • Refactored project layout. Now includes third party libraries, which should reduce effort to build against latest devkitPro releases
  • Updated to latest versions of devkitPPC (r34) and libogc (1.8.23)
  • Merged PR#7 by arocchi
    • Fixes to make wii7800 work with latest DevKit
  • Merged PR#3 by clobber
    • Fix bit shift overflow when reading cartridge size from header
  • Merged PR#2 by clobber
    • Update internal ROM database
  • Merged PR#1 by clobber
    • Correctly load supergame cart types

0.3 - March 29, 2010

  • GX based scaler (smoother scrolling in Plutos, Xevious, Motor Psycho)
  • Ability to adjust screen size to any size/dimensions via the "Screen Size" option under "Display". If this is entered after loading a cartridge, the last frame will be displayed to assist in sizing.
  • Fixed graphical glitches in Ballblazer
  • Implemented RANDOM (read) and SKCTLS (write) for Pokey sound emulation
    • Ballblazer now plays all sounds
  • Minor refactor of Pokey code
  • Some minor adjustments to the Light Gun related code
  • Updated palette (from Underball)
  • Updated menu code, GX rendering of dip switches and debug information
  • Ability to set HBLANK period, Dual-analog support in ProSystem database

0.2 - June 29, 2009

  • 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.

0.1 - May 26, 2009

  • Snapshot support, including auto-load/auto-save
  • Optional loading of 7800 BIOS
  • Support for ProSystem emulator database
  • Detects and configures controls for one and two button 7800 games
  • Controls support for Wiimote/Nunchuk/Classic/Gamecube controllers
  • Analog controls support
  • Dual analog support for Gamecube/Classic controllers (Robotron)