A phenolic cart holding 3 mutually perpendicular search coils is moved through an luminum beam into the magnetic field. Coil voltages re integrated and digitized through a Data Translation 1712 ADC. The cart is controlled and the data is processed by an on-line PDP-11/05 computer. The results are displayed on a Tektronix 4010 terminal, stored on 9 track, 800 bpi tapes, and optionally recorded on a hard copy. Software on a floppy disk controls the system. The position of the cart is located by an encoder and is checked along the beam line by optical switches. One encoder count equals 0.01945 in. The X and Y positions are changed by manipulators at each end of the beam. 625 horizontal or 500 vertical counts equal 1 in. The desired field mapping can be automatically set up by programming a grid of encoder counts on the ''SHOW STATUS'' chart. A ziptrack command summary is given. Following that is a typical procedure for ziptrack operations. Also attached are time constants for the integrators and coil calibrations for 30 ft. and 100 ft. long cables.