I'm running Lubuntu 16 on an old laptop, with a Roland SC-D70 connected. This setup works (eg. I can route MIDI to the device from Rosegarden) but I can't get DXX to use anything but the internal software synth.

I have raised an issue here: https://github.com/dxx-rebirth/dxx-rebirth/issues/719

The current dev is unfortunately not able to help me:

I see your issue, but I cannot help you. The game's MIDI support predates my involvement, and I have never needed to modify its default behavior. I do not know if what you want is possible within the game. I suspect that if your request is possible, then it will be through configuring SDL to use a non-default MIDI device.

So I'm throwing it out to Vogons. Has anyone been able to do this?