An automatic X-Y plotter is described which plots rectangular coordinate graphs from data on perforated paper tape. The X-Y plotter consists basically of a commercial paper tape reader, a Sandia designed control system, and a commercial Variplotter. The paper tape reader provides digital output; the control system converts digital information into an analog voltage acceptable to the Variplotter; and the Variplotter converts the analog input voltage to graphic representation. A description is given of the paper tape format, the method of address selection and storage, operation of the storage selector and shift register including the digital-to-analog conversion, the logic necessary for =om 225,0a0 to operation with one or two tape readers, and calibration procedure. (auth)
