> > Since they repeat, you need some method of jumping around 
> in the sequence.
> > The Basic 'Randomise Timer' was commonly used as the value of TIMER 
> > (system
> > clock) would change, so the starting point in the sequence would 
> > change.  OF course, if the program happened to start at exactly the 
> > same time, you get the same sequence of numbers.
> >
> > In a PIC, you'll need to find something like that, 
> typically from the 
> > environment.  Like Jinx said, maybe the WDT (temperature 
> sensitive).  
> > Hook a light detector to an ADC.  Measure cycles between 
> keypresses and so on.
> >
> > Personally, having the PRNG run continuously might be the 
> easiest option.
> > No guaranted to be random though.
> >
> > Tony
> >
> >   
> Gaming devices use white noise generators which run all the 
> time. A random number is "pulled" from that hardware device 
> when needed. These random events are created by biasing a 
> specially doped diode, amplifying the signal, and measuring 
> the interval between these quick events.
> 
> Randomization is the most difficult thing to accomplish for 
> gaming devices, and state gambling boards require independent 
> testing of each slot machine's randomizer before certifying its use.
> 
> I have seen slot machines pulled for hitting too many 
> jackpots, though; the operators lose confidence in them.
> 
> --Bob.   


I've seen circuits for that somewhere.

Intel (I think) had a plan a few years back to put hardware RNG on PC
motherboards.  Can't remember if it was to go in the CPU (unlikely) or a
separate chip.  Apparently it wasn't random enough.  I'd say manufacturers
didn't want to cough up a few more cents.

Some IVR (telco) gear I worked on had its RNG certified by the British
gaming lot (whoever they are) as being random enough.

Tony

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