The ’HC266 devices have four independent 2-input exclusive-NOR gates and feature open-drain outputs. They perform the Boolean function Y = (A B)\ or Y = AB\ + AB in positive logic.
The ’HC7266 contains four independent Exclusive NOR gates in one package. They provide the system designer with a means for implementation of the EXCLUSIVE NOR function.
The Harris CD4070B contains four independent Exclusive-OR gates. The Harris CD4077B contains four independent Exclusive-NOR gates.