In 2001, I was approached for an emergency rewrite of the firmware for this clock. The original code was purchaced on a per-unit basis by the manufacturer. With a contract dispute in full swing, they were running out of burned chips and had to take action fast. Given only 3 of these clocks as a reference with no source code or other information, I had new firmware up and running in a month's time.

The clocks must drive the spring-loaded arm with just the right resonant frequency. The original firmware was apparently fixed frequency, and did not handle much deviation in manufacturing tolerances. My version would sweep frequencies and find the proper resonant frequency, committing that to memory for next powerup. This resulted in the factory having reject far fewer units than the previous firmware.