John Fields wrote:
On Sun, 24 Oct 2010 14:37:00 -0700, Robert Baer
wrote:

Vladimir Vassilevsky wrote:

Robert Baer wrote:
Vladimir Vassilevsky wrote:

There is approximately a zillion of ways of making quazi random (or
true random) generator from whatever stuff you got in the drawers.
One CANNOT compute (or generate from logic) a truly random number.
Sure you can. Just make a long enough daisy chain of logic gates and
compute a logic function from the input and the output of the chain. Now
apply a clock to the input. As pulse propagates through the chain, the
RMS jitter will add up and the output of the function will be truly
random. Ring Oscillators are the other example, but they are asynchronous.

Now, quasi-random number generators are a dime a dozen, like you imply.
Oh, I forgot to mention the whole class of PRNGs where one counter acts
as a source of the clock for the other counter. That is simple and
allows generation of the variety of random looking sequencies.


Vladimir Vassilevsky
DSP and Mixed Signal Design Consultant
http://www.abvolt.com
Nope! An infinite number of gates has yet to be made.
One of the attributes of a large set of truly random numbers is the
fact that ANY sequence can be repeated, again and again - but not for an
infinite period.

---
If a neverending sequence is truly random, then the possibility exists
that it can repeat forever.


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JF
Not quite..the _probability_ of any repetition is related to the
bitlength under observtion, factored into all of the other possible groups.
Repeat N times, and the probability, starting near zero, gets so
small that the engineering zero is most likely larger..