Mega Drive Midi Interface

Steps to get Mega Drive Midi Interface (MDMI) running on a Genesis/Mega Drive via Mac OS to play FM instruments.

Put MDMI onto your Everdrive
Connect your Everdrive to your Mac via USB
Connect your Midi Keybaord/Sequencer to your Mac via USB
Open Audio Midi Setup from your Utilities folder on Mac OS. Select Midi Studio from the Window menu and then double click the IAC Driver. Make sure "Device is Online" is checked.
Turn on your Mikdi Keyboard and your Genesis/MD and load MDMI
Start up SerialMidiBridge (will take a bit to get the GUI), hit ScanPorts and enter these settings:
- Serial Port: <the one that's not Bluetooth, it'll be a usbserial-something, IE your Everdrive>
- baudrate: 115200
- Serial to Midi: IAC Driver Bus 1
- Midi to Serial: IAC DRiver Bus 1
Once entered hit the Start button in SerialMidiBridge
Start genMDM Editor. Set Midi Input to your Midi Keyboard/Sequencer and Midi Output to IAC Driver Bus 1. Turn on MDMI Mode. If it's already on, toggle it off then on again.

Everything should now be connected. You can load instrument files (like from my library of game instrument patches) and play as well as edit the FM instruments in real time.

You select the midi channel on your keyboard/sequencer to play a note on that channel. The MDMI UI only shows the settings for one channel at a time but you can play any of the 10 channels. Channels 7-10 are PSG channels and can't be edited from genMDM. Changes in genMDM will be live updated on MDMI. Obviously if you have a sequencer or tracker you can play multiple channels at the same time.
All of this only works with genMDM Editor v2.2.0 or greater. For some reason the online version from Github is v2.1.2 which doesn't seem to work. As such I've compiled v2.2.0 from the repo for download here as a standalone Mac app.