I once made an experimental random number generator by using a noisy tarnsistor, op-amp and the ADC. I think the result was quite good.

Never tested that with this Chiquita Square or anything like that. However, the principle itself gives a certain guarantee of non-repeatedness. The spread of values might be the weak point of this one.

Another random number generator was the telephone switch test unit. It had a modified roulette wheel with microswitches on the edges. The microswithes were connected as the ball was bouncing in the wheel. That thing was before the time of any sort of computers.