Integrated Circuits Used 74LS21 74LS02 74LS08 Procedure Add IC 74LS21 into ICBase-1 (74LS21).Add IC 74LS02 into ICBase-2 (74LS02).Add IC 74LS08 into ICBase-3 (74LS08).Connect VCC Port to Pin-2 (Input) of ICBase-2 (74LS02).Connect Output-1 to ICBase-3 (74LS08).