Hi,

I have updated the Challenge and Regency files on Wikipedia to indicate that both models used both versions of the MCU (rom serials A95 and A26).

Although both versions of Challenge are externally identical, in the case of Regency we find that in the modern version the LEDs have been removed, meaning that moves must always be checked on the Display. However, the MCU is the same; the LED PCBs were simply removed to reduce costs.

Best,
Gerardo