Well Actually Steve, The display's may have been wired that way in the schematic originally. Makes no difference. As far as the table is concerned, to generate all 16 hexidecimal characters the table would be 16 entries wide. in the past I have generated tables with all 16 entries as well as lower case "c,n o r". Thats 20. Ther is no standard way if you get my drift. It's completely up to the circuit designer.