randomness

[Tom Libert]

For a cheap truly random number generator, bias a diode
near the switch voltage (around .7V for silicon, if my
hazy memory serves.)  Take the result through an A/D
converter.  Should be Gaussian (or Poisson, I forget);
you could generate a good approximation to a uniform
distribution by inverting the source function (see
e.g. Knuth, "Seminumerical Algorithms" for an algorithm
for producing Gaussian variates from a pair of numbers
drawn from a uniform distribution.)