Integrated Circuits Used 74LS04 74LS153 Procedure Add IC 74LS04 into ICBase-3 (74LS04).Connect Pin-20 (VCC) of ICBase-3 (74LS04) to Pin-20 (VCC) of ICBase-2 (74LS153).Add IC 74LS153 into ICBase-2 (74LS153).