In order to attach physical MIDI keybeds to divisions in GrandOrgue, just right click (or Ctrl-Click, in case you’re on a Mac) on one of the keybeds in the UI. In the dialog, select »Detect complex MIDI setup«, then press the lowest and highest key on the keybed when being asked to do so.

Recently I had the occasion to get in touch with several historic Iberian instruments, which all challenged us with some short octaves. As a consequence, I wanted to practice with one. First I thought I need to update the Palma organ definition file (ODF) accordingly, but it’s much simpler. From the popup labeled »Event:«, just select »9x Note short octave at low key«. And that’s it. The MIDI events of the lowest octave of your console are rearranged by GrandOrgue, e.g. C through D# are silent, E represents C, F# represents D, G# represents E, and the remaining keys work as usual. Don’t forget to save the settings in case you want to keep them.