vendor-doc source, firmware mtg-mega128-1.30, licence not stated, http://www.musictechnologiesgroup.com/files/DX7mega128_UserGuide.pdf; KnobKraft Orm (https://github.com/christofmuc/KnobKraft-orm) by Christof Ruch and contributors, licence AGPL-3.0, https://github.com/christofmuc/KnobKraft-orm/blob/9e2522c/adaptations/YamahaDX7.py Yamaha DX7 (firmware mtg-mega128-1.30)