The 4001 is a member of the 4000 SeriesCMOS range, and contains four independent NOR gates, each with two inputs. The pinout diagram, given on the right, is the standard two-input CMOS logic gate IC layout:
Pin 7 is the negative supply
Pin 14 is the positive supply
Pins 1&2, 5&6, 8&9, 12&13 are gate inputs
Pins 3, 4, 10, 11 are gate outputs
The truth table for one of the four gates is shown to the right. For more information about the NOR gate in general, see this module. The arrangement of the CMOS components is shown below: