Integrated Circuits Used 74LS151 Procedure Add IC 74LS151 into ICBase-3 (74LS151).Connect Pin-20 (VCC) of ICBase-3 (74LS151) to VCC Port.Connect GND Port to Pin-8 (Ground) of ICBase-3 (74LS151).Add IC 74LS151 into ICBase-2 (74LS151).