Using a 555 calculator, he designed a clock circuit ... All it requires is connecting the two circuits in order to synchronize them. It would be easy enough to interface this with an oscillator ...

Our Circuit Design Calculators for Engineers and Students are free-to-use tools that help you quickly determine key parameters ...

LTSpiceIV, available from Linear Technology, allows you to construct moderately complex 555 driven circuits including common components such as capacitors, resistors, diodes, FETs, and more.