The A-500S normally requires that a Roland USB driver be installed on your computer to be able to communicate correctly. If you have an operating system that is not supported, you can set the A-500S to use the MIDI driver that is built into your computer's operating system (for instance, Core MIDI on Mac OSX). To do this:
- Move the Advanced Driver Switch on the side of the keyboard to the "OFF" position.
- Power off and then back on the A-500S.