Nintendo Game Boy Color - 2-Player

The link cable for the Game Boy allows two people to play two-player games. The requirement is that both players insert a Game Pak into their Game Boy, and the Game Pak must feature a two-player mode (the packaging of these games is marked with the appropriate symbol). The link cable is connected to the left side of Game Boy through the sockets specially provided for this, as illustrated on the right.

TGB Dual is an open source (GPLv2) GB/GBC emulator with game link cable support.

We use the latest libretro core. See the official documentation for more information.

ROMs can ordinarily be put into the roms/gbc2players/ folder. This will use a single save file between the linked games, stored in saves/gbc2player. If SYNC SAVE FILES is set to “OFF”/“AUTO” and you're only using a single ROM (duplicated between players), player 2 will use a temporary blank save file that is removed when the session ends. Great for PVP games that don't rely on user save files such as Mario Tennis or Tetris DX.

This is the only available way to use GBC2Player on Batocera v31 and lower.

If instead you'd like to use two different ROMs, read the section on it below.

In Batocera v32 and higher, it is possible to use two different ROMs instead. If you do this without also activating the SYNC SAVE FILES option, an empty save file will be used for Player 2 instead. (this needs to be confirmed)

1. Copy your Game Boy/Game Boy Color ROMs to their respective solo ROM directory, ie. roms/gb and roms/gbc respectively. For example:

   roms/
   ├─ gb/
   │  └─ Pokemon Yellow.zip
   └─ gbc/
      └─ Pokemon Crystal.zip

2. Create a new text file named <game 1 title> and <game 2 title>.gb2 containing the filenames of the games you intend to link play with prepended with gb: or gbc: depending on which folder they're stored in. For example:

   Pokemon Yellow and Pokemon Crystal.gb2

   gb:Pokemon Yellow.zip
   gbc:Pokemon Crystal.zip

   Most Game Boy games could be played on the Game Boy Color, but not all of them.

   Libretro/TGB Dual doesn't care, and will run either game with its appropriate system. Check first before attempting this, so you aren't surprised when your Game Boy game isn't running in Color mode.

3. Save this text file to the roms/gbc2player/ directory. For example:

   roms/
   ├─ gb/
   │  └─ Pokemon Yellow.zip
   ├─ gbc/
   │  └─ Pokemon Crystal.zip
   └─ gbc2players/
      └─ Pokemon Yellow and Pokemon Crystal.gb2

4. Update your game list and now your game will appear in the GBC2Player system!

This is great and all, but what if you also wanted to use two different save files for those games?

Alternative title: POKEMON, YEAH! POKEMON TRADING! AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA!!!

In Batocera v32 and higher, it is possible to use two different ROMs with their respective save files instead. This can be used to say trade Pokemon between different generations.

1. Set up your unique ROMs as detailed above.
2. On the GBC2Player game list, press [SELECT] to bring up the system-specific options and navigate to ADVANCED SYSTEM OPTIONS.
3. Scroll down to SYNC SAVE FILES and set this to “ON”.
4. AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA!!!

When launching a game through the GBC2Player system, the SRM save files for both the ROMs will be temporarily copied from their respective saves/gb/ and/or saves/gbc/ folder(s) to saves/gbc2player/ (overwriting any files currently there). Upon exiting the game, the saves will be copied back from saves/gbc2player to their respective saves/gb/ and/or saves/gbc/ folder(s). This method could also be utilized to do Pokemon battles from your friend's (also emulated) SRM save file.

Save states are not copied, only SRM save files.

The default button mapping to the Game Boy Color is as following: