Built around an Intersil 7216 frequency-counter IC, this counter has a basic range of 10 MHz, a 100-MHz prescaler, and an
extra frequency divider (IC3). This divider divides by an extra factor, as marked on S7 (see schematic), to extend the range of the counter. The display is multiplexed. MAN6710 2-digit red common anode 7-segment LED displays were used on the prototype.