Seven Segment Counter

The display is driven by 74HC47 BCD to seven segment decoder. Before the hexadecimal characters of A,B,C,D,E, and F were adopted, TI and Siemens used the truncated versions of the characters 2,3,4,5, and 6 to denote numbers from 10 to 14, while 15 was a blank. The 74HC4060 ripple counter on the bottom, feeds the seven segment decoder with the BCD numbers.