[SiriusHardware]

I'm not aware of any such files - Karen, as the creator, would be able to tell you better but I think all that was required was to add capacitors across the base resistors of the driver transistors in Karen's original circuit using discrete transistors rather than the 74ACT240 buffer proposed later. The whole project is quite easily built on stripboard, although manually wiring up the strange keypad matrix adopted by SOC is a bit of a chore, I admit.