The main three versions of GX emulators are for NES, SNES and GBA. There are also GX emulators for other consoles/handhelds, but they are less stable.
As the setup and usage of them is around the same, they are all going to be discussed on this page only.
Nintendo Entertainment System (NES)
FCE Ultra GX: http://wiibrew.org/wiki/FCE_Ultra_GX
Super Nintendo Entertainment System (SNES)
Snes9x GX: http://wiibrew.org/wiki/Snes9x_GX
Gameboy Advance (GBA) and Gameboy Color (GBC)
Visual Boy Advance GX: http://wiibrew.org/wiki/Visual_Boy_Advance_GX
Sega Megadrive/Genesis
Genesis plus GX: http://code.google.com/p/genplus-gx/
Sega Master system
SMS Plus GX: http://code.google.com/p/smsplus-gx/
Note: This guide is made for SNES9X GX as it contains the most functions. It might not be completely the same for other Emulators.
Setup
Required
* An SD card (Best results are with non-SDHC cards, SDHC will only work on 4.0 or above) or USB device formatted to FAT(32).
Links
* FCE Ultra GX: Download
* SNES9X GX: Download
* VBA GX: Download
* For other emulators, go to the downloads page on the google code site.
Result
* Setup your GX emulators to play old NES, SNES,GBA or other games.
Guide
Computer ----------------------1. Download the emulator you want and extract the zip file to the root of your SD card/USB Device (let it overwrite/merge stuff if needed). Like that you have the correct folder structure from the beginning.
2. Now get your roms and put them in the roms folder (Which can be found in the folder with the name of the emulator on the SD card)
* If you have any save files, put them in the saves folder (give them the exact same name as the rom it was meant for, but make the extension .sav)
Thats basically it for the setup.
Playing Games
If you did the setup correctly, the emulator will automatically show all roms that are in the roms folder on the SD card (you can change the default folder in the settings).
To start a rom, simply highlight it and press A. Not that hard, eh?
In-game Menu
Like wii games, the in-game menu (home menu) can be accessed by pressing the home button. This menu will give you 4 options:
Save (To save your game at any time)
Load: (To load a previous save)
Game settings
Reset (restart the game)
You can also see the stats of the batteries here.
The close button will resume the game (same for pressing home) and Main menu will exit the game.
Settings
The settings can be accessed from the main screen.
Saving and Loading
gives all options related to saving and loading games. You can change you load devices (SD/USB/SMB) and paths here.
It is advised to leave the Auto Save/Load options to SRAM. (If you change it, you will need to save the game manually to the SRAM in the in-game menu after saving in the actual game)
menu
Exit action: Where to exit to if you press the exit button at the main screen.
For the rest, you can change volumes and Rumble (in the menu) here.
network
Settings for playing games over network.
Game Settings
These settings can be accessed from the in-game menu.
Button mapping
As the name says, change the buttons you want to use here.
On the first screen, you can choose for what original controller the buttons are.
And on the next screen, you can choose what controller you use now.
Video
You can change the scaling (4:3 or 16:9), zoom and filtering here.
Controller
Change what/how many controllers should be emulated.
Cheats
If you have cheats for the game in the cheats folder (the cheat file must be name the same as the game, except for the extension, which should be .cht), you can enable them here.
Real Time Save
Real time save (sometimes called Save states) gives you the ability to save and load your game at any time. This can be used to cheat, or simply to save if you can't find save points.
Using this function is quite easy: in your game, press home at the moment you want to save, and choose save. The first time, you have to create a new snapshot, all following times, you have to choose your existing snapshot from the previous time to overwrite it (unless you want a new snapshot, without losing the old one).
If you need to load the save, just use the load function and choose your saved snapshot.