74251 8-to-1 line 3-state data selector/multiplexer with complementary outputs. +----------+ A3 |1 +--+ 16| VCC A2 |2 15| A4 A1 |3 14| A5 A0 |4 74 13| A6 Y |5 251 12| A7 /Y |6 11| S0 /EN |7 10| S1 GND |8 9| S2 +----------+ [This information is part of the GIICM]