Abstract: A microprocessor for use in individual remote control transmitters for controlling respective different devices and for a unified remote control transmitter for controlling all the devices is programmed in the same manner for each in order to reduce inventory and testing costs to the manufacturer and thereby reduce the cost to consumers. The particular sequence of operation in a given remote control transmitter is determined by external "strap" connections to the input and output terminals of the microprocessor. The remote control messages generated by a remote control transmitter includes preamble and data portions which are dependent on the strap connections and function keys activated by the user and in the case of the unified remote control transmitter by an external memory which stores the device selected for control by means of device selection keys.