Nicer PC HDD activity indicator

Normally computer hard drive activity is indicated with single flashing LED when there is write or read operation performed. [Harvey Wilson] wanted something different then just flashing LED and came out with spindicator. He replaced single LED with 10 LEDs mounted in circular shape.

After digging some info from Internet he found the hdd signal nature and built 4017 counter based circuit which accepts each incoming LED signal and then increments counter. All 10 LEDs are connected to counter output pins so each event lights makes feeling of running lights.