Many of the USB devices I have been looking at for control surfaces are midi-centric, primarily coming out of the music industry. For simple devices, not going the midi-route is usually straight forward, although can get complex supporting cross-platform. For complex devices such as DS1, midi appears to be the best method for dial boxes. There is also economical advantages and an ongoing evolution of such devices. https://www.amazon.com/Livid-Instruments-Portable-Digital-Mixer/dp/B00M4OEWM... It also allows one to take advantage of manufacturer software in configuring baseline operational conditions (setting dial colors, ranges, toggling action of buttons). We have talked about midi in the event loop before. At the time it was not clear how/if this could work under chimeraX. Any further ideas? Matthew Dougherty National Center for Macromolecular Imaging Baylor College of Medicine ================================================= =================================================