A combination X-Y positioning mechanism is disclosed. A first link is linearly reciprocable relative to a frame and a second link is linearly reciprocable relative to the first link. The directions of relative reciprocation are mutually perpendicular. The second link is connected at each end to a flexible belt which engages a series of pulleys between its ends. Two of the pulleys are connected to reversible motors for operation in either direction of rotation. Thus, a member to be moved (connected to the second link) can be positioned at any coordinate position on an X-Y coordinate plane.