A vend control mechanism for a multiple product vending machine is controlled electronically by a master control unit to dispense particular products from storage increments in the machine specifically assigned to those products. A code menu is provided for a service person to input codes into the master...http://www.google.com.tw/patents/US5027283?utm_source=gb-gplus-share專利 US5027283 - Electronically programmable space-to-sales vender
