Integrated Circuits Used 74LS90 74LS11 Procedure Add IC 74LS90 into ICBase-1 (74LS90).Add IC 74LS11 into ICBase-2 (74LS11).Connect Clock port of 5Hz frequency to Pin-20 (Input) of ICBase-1 (74LS90).Connect GND Port to Pin-6 (Input) of ICBase-1 (74LS90).