MMS2-Gameboy Cart Adapter

Game Boy Cartridge Adapter for Multisystem2

The Game Boy Cartridge Adapter for Multisystem2 enables you to play physical cartridges on Multisystem2.

This adapter currently works with the Game Boy (Color) standard and 2-player cores. A custom core is required to use this adapter. Get the custom core here. Use the branch selector to switch to the Gameboy2P branch to obtain the 2-player version.

We have made this adapter open source to encourage developers to make their own addons.

See the releases page for PDF of the schematics, STEP file and gerbers.

Features

• Works with Game Boy and Game Boy Color cartridges
• Hardware support for GBA cartridges but not currently supported by core. We will wait until Robert finishes the 'Accuracy' version of his GBA core as the current core does not closely resemble the real hardware
• Cartridge notch detection switch for auto selection of the correct voltage
• Link port (use a Game Boy Pocket link cable to connect to another system)
• Game cartridge is directly connected to the Game Boy's data bus with no dumping involved so saves work and all special hardware such as the Game Boy Camera should work

Usage

To install the adapter, remove the screw from the underside of the right cover on Multisystem2, remove the right cover, fit the adapter and put the screw back in.

The cartridge will still work if you leave the 24-bit DAC DIP switches on but you might see some very slight noise on the image unless you turn them off.

Download the modified Gameboy and Gameboy2P cores from the link above and put them in the Consoles folder on your SD Card, or at your option, in a new folder to separate them from the stock cores. Note that using the cartridge is an option in these modified cores, so you can still use these modified cores to play ROMs from the SD card too, and don't necessarily need the stock cores as well.

Start the core and in the OSD, turn on the MMS2 Cartridge option.

Hold down the yellow button on the front of the Multisystem2, insert the cartridge and release the button. All signals and power are turned off when the yellow button is held so cartridges can be safely swapped without needing to turn the system off.

If you use the 2-player core, the cartridge will be used for player 1, and player 2 will be the selected ROM from the SD card.

If the game doesn't start or you get the classic garbled Nintendo logo like on original hardware when the cartridge is not making good connection, just hold down the yellow button, reseat the cartridge, and release the button.

The adapter can be safely left installed when using other cores.

The link port can also be used with non-cartridge games but for this to work, you should turn on the option Misc > MMS2 Cartridge Always Poweredand insert a Gameboy cartridge to activate the 5V switch in the adapter for proper voltage levels. Avoid hot-swapping the cartridge when this setting is on. Many games will work when linking one MMS2 to a real Gameboy, but some don't, which we currently believe to be a timing difference between the core and original hardware, as those games work with two MMS2s linked together.