Audio selector
The audio panel switches are connected to the Open Cockpit joystick card and have diodes in circuit to avoid problems with multiple switches on at once. (See Leo Bodner's website for details). Each switch appears as a joystick button press and assigned in FSUIPC to the relavent audio function.
Audio panel completed with 8 switches for audio selections and 3 Marker Beacon indicators, and yes they work along with the audio when the MKR switch is turned on. To the left I have installed a toggle switch (blue) configured to switch the Autopilot UP/DN rocker between Vertical Speed and Altitude selection. Works on all default MSFS aircraft but not all payware add-ons. These often use internally programmed buttons not accessible via FSUIPC etc.

