Integrated Circuits Used 74LS00 Procedure Connect Pin-7 (Input & Output) of ICBase-5 to Pin-5 (Input & Output) of ICBase-5.Connect Pin-18 (Input) of ICBase-3 (74LS00) to Pin-20 (VCC) of ICBase-3 (74LS00).Add IC 74LS00 into ICBase-3 (74LS00).