The Universal Mega Dumper v3 project is an open-source solution for cartridge dumping and writing.
This PCB interfaces a Genesis / Megadrive cartridge to the UMDv3. The UMDv3 Main PCB detects which cartridge adapter is currently connected by reading an ID byte on the I2C bus provided by an MCP23008. The Genesis / Megadrive ID is 0x01.
Please refer to the UMDv3 Firmware Project Repository for UMDv3 documentation and instructions; this is the project's central repository and where the wiki is hosted.
All components in this PCB depend on my KiCad libraries which are available here on github. I don't use any pre-existing libraries - fight me.