9 SMART CARD CASH MANAGEMENT AND USAGE CONTROL SYSTEM HAVING INFRARED DATA COMMUNICATION LINKS FOR CONTROL USING HANDHELD COMPUTING DEVICES, NAMELY, DATA PROCESSORS, enCODED USER CARDS, enCODED CARD READERS, enCODED CARD WRITERS, INFRARED TRANSMITTERS AND RECEIVERS AND ASSOCIATED SWITCHING AND DATA COMMUNICATION INTERFACES, NAMELY, ACTUATORS, TRANSMITTERS, RECEIVERS, AND MODEMS, FOR TRANSFERRING INFORMATION BETWEEN PORTABLE TERMINALS AND VENDING SYSTEMS