2-Player GB/GBC/GBA Custom Cores for MiSTer

FPGA developer Robert Peip aka FPGAzumSpass has been working on 2-player MiSTer cores for the Game Boy, Game Boy Color and Game Boy Advance, that allow two players to play at the same time, using the same MiSTer.  Please check out the details below the links for more information and instructions:

Support Robert’s work:
GBC Core:
GBA Core:
MiSTer Project (these cores require the RAM module):

In order for this very impressive two-player setup to be possible, both cores had to be stripped of any extra features to be able to fit into the FPGA.  As a result, two-player support will never be part of the main GB/GBA cores, simply due to size.  They’re also currently not included in the update_all download (presumably to not confuse people as to why there’s multiple cores), but luckily, manual installation is really easy:

  • Start by going to the Github pages linked above and download the latest .rbf file from the “releases” directory in each.
  • Copy the .rbf files to the “_Console” directory on your MicroSD card
  • Under the “games” directory, create new folders for these cores;  “GAMEBOY2P” and “GBA2P”
  • Copy (not move) the BIOS (boot.rom) files from the root of the original GB/GBA directories to the new folders.
  • Copy the 2-player games you’d like to try to their corresponding directories;  You don’t need to do this, but it’s recommended.  If you’re just looking to test, you can simply navigate to your current GB games directory.
  • Then just power on the MiSTer and load the cores!

The Game Boy / Game Boy Color core supports side-by-side gameplay on both the HDMI and analog outputs (if you have an I/O board);  The display output is cloned to both and they show the same thing.  There’s no options for orientation, as the aspect ratio of GB games works really well in a side-by-side configuration.  You can still change the aspect and scaling method if you’d like, but I thought it looked fine as-is:

The GBA core offers multiple orientation modes, as well as the ability to output Player 2’s screen to the I/O board’s analog output and Player 1 to the HDMI output, allowing for a true dual-screen experience!  Here’s a quick demo showing it in action, as well as the multiple modes available for the LCD output.  Please note that the GB/GBC 2p core doesn’t support the same “one player on each output” configuration, as there’s no DDR3 framebuffer mode available:


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Overall, I’m blown away with how good this works.  There were so many cool 2p games I never got a chance to experience over the years, because I didn’t have two GB’s, a link cable and two copies of the same game.  This is a much easier way to try out some head-to-head action and give the GB’s two player library a try.  I’ll definitely be livestreaming this at some point in the future, so please follow me at:

Also, if you’d like to learn more about Robert and his incredible work in the MiSTer scene, please check out our interview below:

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