MIDI Add-on Board
The MIDI add-on board is a special add-on board that connects to the serial port of an Alpine board and allows a game developer to feed MIDI data to a special version of the Jaguar Synthesizer. This effectively turns the Jaguar into a stand-alone synthesizer which can be controlled by an external keyboard, sequencer, or by a computer equipped with a MIDI port and MIDI software. This allows the game developer to preview their music on the Jaguar itself.
That's about what I know about the board. I did go through, with the help of Carl Forhan (Songbird Productions) loaning me his board, and drew a schematic of the board. Both mine and his board were in-complete in their construction. But between the two boards, I was able to figure how to make them complete.
Click on the picture to view/download an Adobe PDF of the schematic drawing of the board.
Note: The MIDI add-on board does require modifications to be made to the Alpine board to allow proper functionality. According to Atari's documentation, newere releases of the Alpine board come with a 32MHz crystal and a 10 pin header fitted in space J4. Only those Alpines with those components can be used with the MIDI add-on board. These modifications will be later described here when I've tested ensure they work.