Volume: FYI the A300 has a mechanical link from the Yaw Damper which goes to all 3 rudder actuators (each one servo assisted) via a spring rod. The autopilot yaw actuator also has an input. The YD actuator, the AP actuator and rudder pedal inputs are all "upstream" of a variable stop lever which limits mechanical travel input depending on speed.
Makes FBW sound like a doddle!