4000 Dual 3-input NOR gates and inverter. +----------+ ________ |1 +--+ 14| VCC /1Y=1A+1B+1C |2 13| 3C 1A |3 12| 3B __ 1B |4 4000 11| 3A /2Y=2A 1C |5 10| /3Y /1Y |6 9| /2Y ________ GND |7 8| 2A /3Y=3A+3B+3C +----------+