Giuseppe built his CMOS digital clock two years ago and decided to enter it into the Open 7400 Logic Competition.
By using a 2Mhz quartz crystal and a 21bit counter he managed to make a 1Hz clock signal which drives his design. Implementing 2 binary counters programed to count to 60 he managed to get minutely and hourly pulses. The time is displayed on a 7 segment display. A schematic is available on his site.
Via the contact form.