If you have ever tried to use your Hammond XK-3 for playing the VB3 or B4 organ plug-ins you may have encountered a big problem - whilst in the above mentioned plug-in organs each drawbar responds to a particular CC message number, the XK-3 drawbars send out only three CC message numbers: #80 for all the upper drawbars, #81 for all the lower drawbars and #82 for the two pedal drawbars.
Simply open it in your VST host application, connect the host MIDI input to the DMfXK-3's MIDI input and its MIDI output to the MIDI input of the plug-in organ. The 4 LEDs indicate which plug-in's drawbars set is moved or if other MIDI messages (notes, other CCs, etc.) are sent to the plug-in.
Drawbars Mapper for XK-3 is Donationware and is available as a VST instrument plug-in for Windows.