Apparatus for setting and displaying a numerical value to be encoded to an electronic device, including a molded plastic support structure, a printed circuit board membrane type switch assembly which is affixed to the support structure and which includes a plurality of rows of four switches, and a like plurality of molded plastic switch actuator shafts associated respectively with the rows of four switches. Each actuator shaft has a longitudinal axis extending parallel to the associated row of four switches, and is pivotally connected to the support structure for rotation about its axis. Each shaft includes a plurality of raised annular segments for opening and closing the four switches in the adjacent row. The segments are arranged so as to provide ten combinations of open and closed switches as the shaft is rotated, to provide a 4-bit binary code corresponding to one of ten numbers 0-9, depending on the rotary shaft position. Also, each shaft includes the ten numbers 0-9 disposed about the shaft axis on the front surface of a shaft flange such that the number adjacent an indicator on the support structure corresponds to the binary code setting. The numbers 0-9 carried by each actuator shaft are oriented such that the indicated numbers are readable as a discrete number in standard decimal format corresponding to the numerical value to be encoded.
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