7402

The 7402 (variants 74LS02, 74HC02) is a 74-series logic IC with four independent 2-Input NOR gates.

74161 Pinout

              .--\/--.
         Y1 --|01  14|-- +5V
         A1 --|02  13|-- Y4
         B1 --|03  12|-- B4
         Y2 --|04  11|-- A4
         A2 --|05  10|-- Y3
         B2 --|06  09|-- B3
        Gnd --|07  08|-- A3
              `------'

Signal descriptions

Y is low if either A or B is high, and is high if A and B are both low.