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.