What are good PRNG for calculators?

[brouhaha]

(08-25-2014 05:15 PM)Marcus von Cube Wrote:  The TI SR-51(A) has a RAN# function that returns a two digit random number. I couldn't find more info about it but I have the feeling that it's not a pseudo random number generator but a real random number function. Can someone confirm this? To support my assumption, there is no seed function.

I expect it's a PRNG. There's no RNG hardware in the 51, so the only source of "random" numbers would be timing of key presses, and they can't get enough bits of entropy from a single key press for a two digit number. During a running program, using RAN# repeately would have no entropy input, so even if they time keypresses it would only be useful as a seed.

If the RAN# doesn't give the same results after each power-up, that could be due to not initializing the storage for the PRNG, which would act as a semi-random seed, though the entropy content would be very low.