Integrated Circuits Used 74LS74 Procedure Add IC 74LS74 into ICBase-3 (74LS74).Add IC 74LS74 into ICBase-2 (74LS74).Connect VCC Port to Pin-1 (Input) of ICBase-2 (74LS74).Connect VCC Port to Pin-4 (Input) of ICBase-2 (74LS74).