this is my self experiment by the help of my own knowledge teach to me when im college a student. this circuit show that when the number reach at 9 it will became 0 not A. and as the number increase it will transfer it existing or a number higher than 9. that why this circuit will count from 1 to 999 and reset to 0 and count again. and the letter A,b,C,d,E,and F will not appear. i need to keep this from simple to be complicated as a modern computer how's that. hahaha. comment if you like it or i will delete it if not appreciate and recreate a new.
