Hello:

This is the first electronic project that I've done when I was 14(Junior 1). It's a digital clock. It took me 1 year to finish, because it's also been a learning process for me. There were some CMOS MC4510 and MC4511 etc.


This is the bottom of the clock, from where you can see the difference between circuits. There is great improvement between the first board and the last board.


One year later I made another one, which is still running on my desk(The black one above):


and this is the circuit inside the small clock:


Now I can make a clock on a 5cm X 5cm PCB, with a 89C2051. I find it interesting to compare these projects.

Stanley