Integrated Circuits Used 74LS02 Procedure Add IC 74LS02 into ICBase-2 (74LS02).Add IC 74LS02 into ICBase-3 (74LS02).Add IC 74LS02 into ICBase-4 (74LS02).Connect Pin-20 (VCC) of ICBase-3 (74LS02) to VCC Port.