Abstract: A programmable display engineering scale instrument includes a scale base such as a drafting machine type scale, an electronic display device including a plurality of rows of column aligned display elements, scale selection switches, and circuitry interpreting the operation of the selection switches to cause the display of corresponding linear scales. The circuitry includes a switch encoder which generates unique binary addresses corresponding to each of the switches. A memory device stores bit patterns which when addressed cause the activation of patterns of display elements to display a corresponding linear scale. The display elements are interconnected in selected groups for simultaneous activation to simplify the circuitry of the programmable scale instrument.