74266
Quad 2-input open-collector XNOR gates.

    +----------+             +-----------+          _     _ _
 1A |1  +--+ 14| VCC         | A | B |/Y |     Y = A$B = (A*B)+(A*B)
 1B |2       13| 4B          |---+---+---|
/1Y |3  74   12| 4A          | 0 | 0 | Z |
 2A |4  266  11| /4Y         | 0 | 1 | 0 |
 2B |5       10| 3B          | 1 | 0 | 0 |
/2Y |6        9| 3A          | 1 | 1 | Z |
GND |7        8| /3Y         +-----------+
    +----------+

[This information is part of the GIICM]