Interface for Optional Features in a Point of Sale Sy
Original Publication Date: 1981-Apr-01
Included in the Prior Art Database: 2005-Feb-11
Interface card 1 is designed to operate on the microprocessor data bus, with specific address locations (FF40=Status/Interrogation, FF50=Condition FF60=Data Input and FF70=Diagnostics) being assigned definite operational functions, which are not normally assigned to memory data storage locations. One card was designed to accommodate the data transfer (parallel by bit) for the OCR-A/B type optical characters, bar codes (both EAN and UPC) and print/punch ticket readers. To accommodate the physical interface differences, two separate cables 2 and 3 are used. A unique pin in each cable is grounded to serve as an identifier to the control program as to the type of device connected, in addition to indicating that the cable is physically and properly attached.