Generating truly random numbers using a purely digital circuit is not possible – after all, digital logic is supposed to give the same results given the same input! This circuit cheats a little – a 4049 is used in an analog manner, amplifying and digitizing diode noise.
Build something that uses or abuses a logic chip and get amazing boards, tools, and other swag. The Open 7400 Logic Competition promotes awareness of the basic building blocks of modern circuits. Devious geeks ignited the computer revolution with discrete logic computers, what can you do? Details and entry form here.