ok, I tried that, but nothing happens. I set the output buffer size to 60000, correctly selected megadrum device, loaded the correct sysex file, booted megadrum before starting MIDI-OX, left the clock at 16 mhz and pressed down. Then I tried to send the sysex file, but nothing happened.
I tried to close MIDI-OX but it is stuck in "closing MIDI devices" now.