Integrated Circuits Used 74LS90 74LS08 Procedure Add IC 74LS90 into ICBase-1 (74LS90).Add IC 74LS08 into ICBase-3 (74LS08).Connect VCC Port to Pin-20 (VCC) of ICBase-3 (74LS08).Connect GND Port to Pin-7 (Ground) of ICBase-3 (74LS08).