What would we do without them?
+---+--+---+ +---+---*---+ __ 1A |1 +--+ 14| VCC | A | B |/Y | /Y = AB 1B |2 13| 4B +===+===*===+ /1Y |3 12| 4A | 0 | 0 | 1 | 2A |4 7400 11| /4Y | 0 | 1 | 1 | 2B |5 10| 3B | 1 | 0 | 1 | /2Y |6 9| 3A | 1 | 1 | 0 | GND |7 8| /3Y +---+---*---+ +----------+
+---+--+---+ +---+---*---+ __ /1Y |1 +--+ 14| VCC | A | B |/Y | /Y = AB 1A |2 13| /4Y +===+===*===+ 1B |3 12| 4B | 0 | 0 | Z | /2Y |4 7401 11| 4A | 0 | 1 | Z | 2A |5 10| /3Y | 1 | 0 | Z | 2B |6 9| 3B | 1 | 1 | 0 | GND |7 8| 3A +---+---*---+ +----------+
+---+--+---+ +---+---*---+ ___ /1Y |1 +--+ 14| VCC | A | B |/Y | /Y = A+B 1A |2 13| /4Y +===+===*===+ 1B |3 12| 4B | 0 | 0 | 1 | /2Y |4 7402 11| 4A | 0 | 1 | 0 | 2A |5 10| /3Y | 1 | 0 | 0 | 2B |6 9| 3B | 1 | 1 | 0 | GND |7 8| 3A +---+---*---+ +----------+
+---+--+---+ +---+---*---+ __ 1A |1 +--+ 14| VCC | A | B |/Y | /Y = AB 1B |2 13| 4B +===+===*===+ /1Y |3 12| 4A | 0 | 0 | Z | 2A |4 7403 11| /4Y | 0 | 1 | Z | 2B |5 10| 3B | 1 | 0 | Z | /2Y |6 9| 3A | 1 | 1 | 0 | GND |7 8| /3Y +---+---*---+ +----------+
+---+--+---+ +---*---+ _ 1A |1 +--+ 14| VCC | A |/Y | /Y = A /1Y |2 13| 6A +===*===+ 2A |3 12| /6Y | 0 | 1 | /2Y |4 7404 11| 5A | 1 | 0 | 3A |5 10| /5Y +---*---+ /3Y |6 9| 4A GND |7 8| /4Y +----------+
+---+--+---+ +---*---+ _ 1A |1 +--+ 14| VCC | A |/Y | /Y = A /1Y |2 13| 6A +===*===+ 2A |3 12| /6Y | 0 | Z | /2Y |4 7405 11| 5A | 1 | 0 | 3A |5 10| /5Y +---*---+ /3Y |6 9| 4A GND |7 8| /4Y +----------+
+---+--+---+ +---*---+ _ 1A |1 +--+ 14| VCC | A |/Y | /Y = A /1Y |2 13| 6A +===*===+ 2A |3 12| /6Y | 0 | Z | /2Y |4 7406 11| 5A | 1 | 0 | 3A |5 10| /5Y +---*---+ /3Y |6 9| 4A GND |7 8| /4Y +----------+
+---+--+---+ +---*---+ 1A |1 +--+ 14| VCC | A | Y | Y = A 1Y |2 13| 6A +===*===+ 2A |3 12| 6Y | 0 | 0 | 2Y |4 7407 11| 5A | 1 | Z | 3A |5 10| 5Y +---*---+ 3Y |6 9| 4A GND |7 8| 4Y +----------+
+---+--+---+ +---+---*---+ 1A |1 +--+ 14| VCC | A | B | Y | Y = AB 1B |2 13| 4B +===+===*===+ 1Y |3 12| 4A | 0 | 0 | 0 | 2A |4 7408 11| 4Y | 0 | 1 | 0 | 2B |5 10| 3B | 1 | 0 | 0 | 2Y |6 9| 3A | 1 | 1 | 1 | GND |7 8| 3Y +---+---*---+ +----------+
+---+--+---+ +---+---*---+ 1A |1 +--+ 14| VCC | A | B | Y | Y = AB 1B |2 13| 4B +===+===*===+ 1Y |3 12| 4A | 0 | 0 | 0 | 2A |4 7409 11| 4Y | 0 | 1 | 0 | 2B |5 10| 3B | 1 | 0 | 0 | 2Y |6 9| 3A | 1 | 1 | Z | GND |7 8| 3Y +---+---*---+ +----------+
+---+--+---+ +---+---+---*---+ ___ 1A |1 +--+ 14| VCC | A | B | C |/Y | /Y = ABC 1B |2 13| 1C +===+===+===*===+ 2A |3 12| /1Y | 0 | X | X | 1 | 2B |4 7410 11| 3C | 1 | 0 | X | 1 | 2C |5 10| 3B | 1 | 1 | 0 | 1 | /2Y |6 9| 3A | 1 | 1 | 1 | 0 | GND |7 8| /3Y +---+---+---*---+ +----------+
+---+--+---+ +---+---+---*---+ 1A |1 +--+ 14| VCC | A | B | C | Y | Y = ABC 1B |2 13| 1C +===+===+===*===+ 2A |3 12| 1Y | 0 | X | X | 0 | 2B |4 7411 11| 3C | 1 | 0 | X | 0 | 2C |5 10| 3B | 1 | 1 | 0 | 0 | 2Y |6 9| 3A | 1 | 1 | 1 | 1 | GND |7 8| 3Y +---+---+---*---+ +----------+
+---+--+---+ +---+---+---*---+ ___ 1A |1 +--+ 14| VCC | A | B | C |/Y | /Y = ABC 1B |2 13| 1C +===+===+===*===+ 2A |3 12| /1Y | 0 | X | X | Z | 2B |4 7410 11| 3C | 1 | 0 | X | Z | 2C |5 10| 3B | 1 | 1 | 0 | Z | /2Y |6 9| 3A | 1 | 1 | 1 | 0 | GND |7 8| /3Y +---+---+---*---+ +----------+
+---+--+---+ +---+---+---+---*---+ ____ 1A |1 +--+ 14| VCC | A | B | C | D |/Y | /Y = ABCD 1B |2 13| 2D +===+===+===+===*===+ |3 12| 2C | 0 | X | X | X | 1 | 1C |4 7413 11| | 1 | 0 | X | X | 1 | 1D |5 10| 2B | 1 | 1 | 0 | X | 1 | /1Y |6 9| 2A | 1 | 1 | 1 | 0 | 1 | GND |7 8| /2Y | 1 | 1 | 1 | 1 | 0 | +----------+ +---+---+---+---*---+
+---+--+---+ +---*---+ _ 1A |1 +--+ 14| VCC | A |/Y | /Y = A /1Y |2 13| 6A +===*===+ 2A |3 12| /6Y | 0 | 1 | /2Y |4 7414 11| 5A | 1 | 0 | 3A |5 10| /5Y +---*---+ /3Y |6 9| 4A GND |7 8| /4Y +----------+
+---+--+---+ +---+---+---*---+ 1A |1 +--+ 14| VCC | A | B | C | Y | Y = ABC 1B |2 13| 1C +===+===+===*===+ 2A |3 12| 1Y | 0 | X | X | 0 | 2B |4 7415 11| 3C | 1 | 0 | X | 0 | 2C |5 10| 3B | 1 | 1 | 0 | 0 | 2Y |6 9| 3A | 1 | 1 | 1 | Z | GND |7 8| 3Y +---+---+---*---+ +----------+
+---+--+---+ +---*---+ _ 1A |1 +--+ 14| VCC | A |/Y | /Y = A /1Y |2 13| 6A +===*===+ 2A |3 12| /6Y | 0 | Z | /2Y |4 7416 11| 5A | 1 | 0 | 3A |5 10| /5Y +---*---+ /3Y |6 9| 4A GND |7 8| /4Y +----------+
+---+--+---+ +---*---+ 1A |1 +--+ 14| VCC | A | Y | Y = A 1Y |2 13| 6A +===*===+ 2A |3 12| 6Y | 0 | 0 | 2Y |4 7417 11| 5A | 1 | Z | 3A |5 10| 5Y +---*---+ 3Y |6 9| 4A GND |7 8| 4Y +----------+
+---+--+---+ +---+---+---+---*---+ ____ 1A |1 +--+ 14| VCC | A | B | C | D |/Y | /Y = ABCD 1B |2 13| 2D +===+===+===+===*===+ |3 12| 2C | 0 | X | X | X | 1 | 1C |4 7418 11| | 1 | 0 | X | X | 1 | 1D |5 10| 2B | 1 | 1 | 0 | X | 1 | /1Y |6 9| 2A | 1 | 1 | 1 | 0 | 1 | GND |7 8| /2Y | 1 | 1 | 1 | 1 | 0 | +----------+ +---+---+---+---*---+
+---+--+---+ +---*---+ _ 1A |1 +--+ 14| VCC | A |/Y | /Y = A /1Y |2 13| 6A +===*===+ 2A |3 12| /6Y | 0 | 1 | /2Y |4 7414 11| 5A | 1 | 0 | 3A |5 10| /5Y +---*---+ /3Y |6 9| 4A GND |7 8| /4Y +----------+
+---+--+---+ +---+---+---+---*---+ ____ 1A |1 +--+ 14| VCC | A | B | C | D |/Y | /Y = ABCD 1B |2 13| 2D +===+===+===+===*===+ |3 12| 2C | 0 | X | X | X | 1 | 1C |4 7420 11| | 1 | 0 | X | X | 1 | 1D |5 10| 2B | 1 | 1 | 0 | X | 1 | /1Y |6 9| 2A | 1 | 1 | 1 | 0 | 1 | GND |7 8| /2Y | 1 | 1 | 1 | 1 | 0 | +----------+ +---+---+---+---*---+
+---+--+---+ +---+---+---+---*---+ 1A |1 +--+ 14| VCC | A | B | C | D | Y | Y = ABCD 1B |2 13| 2D +===+===+===+===*===+ |3 12| 2C | 0 | X | X | X | 0 | 1C |4 7421 11| | 1 | 0 | X | X | 0 | 1D |5 10| 2B | 1 | 1 | 0 | X | 0 | 1Y |6 9| 2A | 1 | 1 | 1 | 0 | 0 | GND |7 8| 2Y | 1 | 1 | 1 | 1 | 1 | +----------+ +---+---+---+---*---+
+---+--+---+ +---+---+---+---*---+ ____ 1A |1 +--+ 14| VCC | A | B | C | D |/Y | /Y = ABCD 1B |2 13| 2D +===+===+===+===*===+ |3 12| 2C | 0 | X | X | X | Z | 1C |4 7422 11| | 1 | 0 | X | X | Z | 1D |5 10| 2B | 1 | 1 | 0 | X | Z | /1Y |6 9| 2A | 1 | 1 | 1 | 0 | Z | GND |7 8| /2Y | 1 | 1 | 1 | 1 | 0 | +----------+ +---+---+---+---*---+
+---+--+---+ +---+---*---+ __ 1A |1 +--+ 14| VCC | A | B |/Y | /Y = AB 1B |2 13| 4B +===+===*===+ /1Y |3 12| 4A | 0 | 0 | 1 | 2A |4 7424 11| /4Y | 0 | 1 | 1 | 2B |5 10| 3B | 1 | 0 | 1 | /2Y |6 9| 3A | 1 | 1 | 0 | GND |7 8| /3Y +---+---*---+ +----------+
+---+--+---+ __________ 1A |1 +--+ 14| VCC Y = G(A+B+C+D) 1B |2 13| 2D 1G |3 12| 2C 1C |4 7425 11| 2G 1D |5 10| 2B /1Y |6 9| 2A GND |7 8| /2Y +----------+
+---+--+---+ +---+---*---+ __ 1A |1 +--+ 14| VCC | A | B |/Y | /Y = AB 1B |2 13| 4B +===+===*===+ /1Y |3 12| 4A | 0 | 0 | Z | 2A |4 7426 11| /4Y | 0 | 1 | Z | 2B |5 10| 3B | 1 | 0 | Z | /2Y |6 9| 3A | 1 | 1 | 0 | GND |7 8| /3Y +---+---*---+ +----------+
+---+--+---+ +---+---+---*---+ _____ 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 +---+---+---*---+ +----------+
+---+--+---+ +---+---*---+ ___ /1Y |1 +--+ 14| VCC | A | B |/Y | /Y = A+B 1A |2 13| /4Y +===+===*===+ 1B |3 12| 4B | 0 | 0 | 1 | /2Y |4 7428 11| 4A | 0 | 1 | 0 | 2A |5 10| /3Y | 1 | 0 | 0 | 2B |6 9| 3B | 1 | 1 | 0 | GND |7 8| 3A +---+---*---+ +----------+
+---+--+---+ ________ A |1 +--+ 14| VCC /Y = ABCDEFGH B |2 13| C |3 12| H D |4 7430 11| G E |5 10| F |6 9| GND |7 8| /Y +----------+
+---+--+---+ _ _____ 1A |1 +--+ 16| VCC /1Y=1A /4Y=4A.4B /1Y |2 15| 6A 2A |3 14| /6Y 2Y=2A 5Y=5A 2Y |4 13| 5A _____ _ 3A |5 7431 12| 5Y /3Y=3A.3B /6Y=6A 3B |6 11| 4B /3Y |7 10| 4A GND |8 9| /4Y +----------+
+---+--+---+ +---+---*---+ 1A |1 +--+ 14| VCC | A | B | Y | Y = A+B 1B |2 13| 4B +===+===*===+ 1Y |3 12| 4A | 0 | 0 | 0 | 2A |4 7432 11| 4Y | 0 | 1 | 1 | 2B |5 10| 3B | 1 | 0 | 1 | 2Y |6 9| 3A | 1 | 1 | 1 | GND |7 8| 3Y +---+---*---+ +----------+
+---+--+---+ +---+---*---+ ___ /1Y |1 +--+ 14| VCC | A | B |/Y | /Y = A+B 1A |2 13| /4Y +===+===*===+ 1B |3 12| 4B | 0 | 0 | Z | /2Y |4 7433 11| 4A | 0 | 1 | 0 | 2A |5 10| /3Y | 1 | 0 | 0 | 2B |6 9| 3B | 1 | 1 | 0 | GND |7 8| 3A +---+---*---+ +----------+
+---+--+---+ +---+---*---+ __ 1A |1 +--+ 14| VCC | A | B |/Y | /Y = AB 1B |2 13| 4B +===+===*===+ /1Y |3 12| 4A | 0 | 0 | 1 | 2A |4 7437 11| /4Y | 0 | 1 | 1 | 2B |5 10| 3B | 1 | 0 | 1 | /2Y |6 9| 3A | 1 | 1 | 0 | GND |7 8| /3Y +---+---*---+ +----------+
+---+--+---+ +---+---*---+ __ 1A |1 +--+ 14| VCC | A | B |/Y | /Y = AB 1B |2 13| 4B +===+===*===+ /1Y |3 12| 4A | 0 | 0 | Z | 2A |4 7438 11| /4Y | 0 | 1 | Z | 2B |5 10| 3B | 1 | 0 | Z | /2Y |6 9| 3A | 1 | 1 | 0 | GND |7 8| /3Y +---+---*---+ +----------+
+---+--+---+ +---+---+---+---*---+ ____ 1A |1 +--+ 14| VCC | A | B | C | D |/Y | /Y = ABCD 1B |2 13| 2D +===+===+===+===*===+ |3 12| 2C | 0 | X | X | X | 1 | 1C |4 7440 11| | 1 | 0 | X | X | 1 | 1D |5 10| 2B | 1 | 1 | 0 | X | 1 | /1Y |6 9| 2A | 1 | 1 | 1 | 0 | 1 | GND |7 8| /2Y | 1 | 1 | 1 | 1 | 0 | +----------+ +---+---+---+---*---+
+---+--+---+ +---+---+---+---*---+---+---+---+ /Y0 |1 +--+ 16| VCC | S3| S2| S1| S0|/Y0|/Y1|...|/Y9| /Y1 |2 15| S0 +===+===+===+===*===+===+===+===+ /Y2 |3 14| S1 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | /Y3 |4 13| S2 | 0 | 0 | 0 | 1 | 1 | 0 | 1 | 1 | /Y4 |5 7442 12| S3 | . | . | . | . | 1 | 1 | . | 1 | /Y5 |6 11| /Y9 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 0 | /Y6 |7 10| /Y8 | 1 | 0 | 1 | X | 1 | 1 | 1 | 1 | GND |8 9| /Y7 | 1 | 1 | X | X | 1 | 1 | 1 | 1 | +----------+ +---+---+---+---*---+---+---+---+
+---+--+---+ A1 |1 +--+ 16| VCC A2 |2 15| /YF /LT |3 14| /YG /RBO |4 13| /YA /RBI |5 7447 12| /YB A3 |6 11| /YC A0 |7 10| /YD GND |8 9| /YE +----------+
+---+--+---+ A1 |1 +--+ 16| VCC A2 |2 15| YF /LT |3 14| YG /RBO |4 13| YA /RBI |5 7448 12| YB A3 |6 11| YC A0 |7 10| YD GND |8 9| YE +----------+