1. An alphanumeric display device mounted on a movable arm of a three dimensional coordinate measuring system, said movable arm having a probe end and including a plurality of joints with each joint corresponding to a degree of freedom such that the arm is moveable within a selected volume, each of the joints comprises a rotational transfer housing having a positional transducer disposed therein producing a signal corresponding to a position, the system further having a microprocessor receiving the position signals and providing a digital coordinate corresponding to the position of the probe in the selected volume, the alphanumeric display device receiving the digital coordinate and displaying the coordinate.