Integrated Circuits Used 74LS04 74LS08 Procedure Add IC 74LS04 into ICBase-1 (74LS04).Add IC 74LS08 into ICBase-2 (74LS08).Add IC 74LS08 into ICBase-3 (74LS08).Connect Pin-15 (Input & Output) of ICBase-4 to Pin-15 (Input) of ICBase-3 (74LS08).