Electrographic apparatus

An electrographic apparatus or digitizer has a resistive layer with an active area which operates in conjunction with a stylus or other suitable position locator. An a.c. source or alternatively a signal treatment means is connected to the resistive layer through rows of electrodes and position coordinates of the position locator are developed by the apparatus. Voids or discontinuities are formed in the resistive layer to increase the edge-to-edge resistance of the layer and to provide identical edge-to-edge resistances in the x- and the y-coordinate direction for digitizers which are rectangular and non-square.