Abstract: A small computer unit is disclosed that is installable in any standard vending machine that dispenses a product that, by law, is restricted to adult use only, such as cigarette or beer vending machines. An insertion slot is placed on the vending machine to receive the driver's license, and an optical reader then reads the date. A microprocessor then calculates the individuals age based upon the difference between the birth date on the driver's license and the current date, which is maintained by an internal clock. A diverter switch in communication with the coin slot and the coin return is then positioned based upon the user's age. If the user is under a predetermined age, usually either 18 or 21 years old, then the diverter switch directs the coins to pass directly to the coin return, thereby preventing dispensing of product. If the user is of legal age, the diverter switch allows coins to pass into the vending machine in order to operate in a normal conventional manner.