74157

The 74157 (variants 74LS157, 74HC157) is a 74-series logic IC with four 2-input multiplexers sharing a single select line.

74157 Pinout

      .--\/--.
  S - |01  16| - +5V
1I0 - |02  15| - /E
1I1 - |03  14| - 4I0
 1Y - |04  13| - 4I1
2I0 - |05  12| - 4Y
2I1 - |06  11| - 3I0
 2Y - |07  10| - 3I1
Gnd - |08  09| - 3Y
      `------'

Signal descriptions

If /E is high, then all 4 Y output pins output as low, otherwise, if S is low, for each set of pins starting with the same number, Y is equal to I0, otherwise, if S is high, then Y is equal to I1.