RESET circuit

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One thing I had to add was a power-up RESET circuit, which is just a 10uF cap and 1K resistor in series across the 5v supply. The RESET pin on the counters are connected to where the resistor and cap meet so that at power up, the cap is effectively a short to 5+. This causes a logic HI on the RESET lines to set the counters to zero. After the capacitor has charged up, it no longer looks like a short to 5+, so the only path left is through the resistor back to ground. That presents a logic LOW on the RESET pin, which allows the counter to count up or down.

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