7427 Triple 3-input NOR gates. +----------+ +---------------+ _____ 1A |1 +--+ 14| VCC | A | B | C |/Y | /Y = A+B+C 1B |2 13| 1C |---+---+---+---| 2A |3 12| /1Y | 0 | 0 | 0 | 1 | 2B |4 7427 11| 3C | 0 | 0 | 1 | 0 | 2C |5 10| 3B | 0 | 1 | X | 0 | /2Y |6 9| 3A | 1 | X | X | 0 | GND |7 8| /3Y +---------------+ +----------+ [This information is part of the GIICM]