Abstract: The foregoing and other objects of the invention are achieved by a drive system which includes a base and a support assembly for rotatably supporting one end of the first arm from said base and for raising and lowering the arm with respect to the base. A second arm has one end rotatably supported at the other end of the first arm and an effector mount is rotatably supported at the other end of the second arm. Drive structure mounted on said base rotate said support assembly. Drive structure mounted at the lower end of said support assembly raise and lower the arm. Drive structure for rotating said second arm and drive structure for rotating said effector are mounted at the upper end of said support. All of said drive structure are mounted within an enclosed housing.