Model 9862A calculator plotter, 1973
An x-y plotter is an electromechanical device that produces permanent graphical displays of two input variables as they relate to each other. A plotter made it possible to chart automatically rather than by hand the relation of friction to heat, for example, or vibration to velocity, current to voltage or the relation of any other set of variables.
The 9862A plotter operated in all four quadrants. Under the control of a Peripheral Control Function Block, the x-y plotter could automatically scale data, generate words as well as numbers and set up both axes complete with labels and tick marks. It sold for $2,780.
A peripheral for the 9800 series programmable desktop calculator, the 9862A x-y plotter could draw and write histograms, pie-charts and circuit diagrams.