Abstract: A mechanically programmable read only memory in the form of a card for use with a reading circuit to which the card is applied, an insulating substrate with a multiplicity of resistive coating strips arranged in a pattern on the face of a substrate, a multiplicity of circuit interrupters between corresponding ends of resistive strips and being removable along with any surface media applied thereover; conductor strips laid over the circuit interrupters and intersecting with the resistive strips for electrical connection therewith; additional conductor strips or bus strips applied on the substrate to intersect with the other ends of the resistive strips, all of the conductor strips having ends clustered at one edge of the substrate forming connector contacts for assembly with such reading circuitry; the resistive strips, circuit interrupters, and conductor strips being applied by screen printing technology; the circuit interrupters being formed of scratch off ink or mechanically abradable and removable ink; the