A wafer handling robot is disclosed for transporting workpieces such as semiconductor wafers and flat panel displays between process tools and/or workpiece storage locations within a wafer fab. The robot includes a base comprising a rigid backbone for providing a significant degree of structural stability to the robot. The base further includes a mast, a linear drive system for translating the mast, and a shoulder drive system for rotating the mast. The shoulder drive system includes a harmonic drive reduction system for providing a stiff, smooth and precise output rotation of the mast section. The robot further includes a proximal link fixedly mounted to the mast for rotation with the mast, and a distal link rotatably mounted to the proximal link. An end effector for supporting various workpieces is rotationally mounted to the distal end of the distal link. An elbow drive is mounted to the proximal link, extending down into the mast section, for driving rotation of the distal link with respect to the proximal link. Torque is transmitted from the elbow drive to the distal link by steel straps wrapped around a drive pulley from the elbow drive and a driven pulley in the distal link. Similarly, torque is transmitted from the distal link to the end effector via a second set of steel straps wrapped around pulleys provided in the distal link and end effector, respectively.