Texas Instruments’ 5400 and 7400 TTL quad 2-input NAND gate has been in continuous production since 1964 and is the progenitor of what is probably the most numerous breed of integrated circuits, ...

are digital logic gates that output true or high (1) only when the number of true inputs is even. Essentially, they are the complement of XOR gates. The XNOR gate combines the functionality of an XOR ...