I wanted to spot check the quality of the random numbers generated by
NOISE.SYS

I read that:

> Statistically testing a PRNG requires quite a lot (10 or even 100 GB)

AND

> All tests of RNGs are based on a "null hypothesis", meaning if they
> fail, they show the RNG may be flawed. But if they pass, it does
> not mean it is good.

Keeping these in mind, i decided that ENT was good enough for me.

ENT home page
<https://www.fourmilab.ch/random/>

ENT DJGPP build
<gopher://tilde.pink/9/~bencollver/files/dos386/util/gnupg/ent14.zip>

Comparing the resulting Chi-square percentages:

* Linux has 93.44% (almost suspect) and
* NOISE.SYS has 97.88% (suspect).

This seems to indicate a problem in NOISE.SYS.
I'm a hacker not a cryptographer, so i don't know how to fix it.

Linux
=====

$ dd if=/dev/random of=linux.dat bs=1024 count=1024
$ ent <linux.dat

    Entropy = 7.999848 bits per byte.
   
    Optimum compression would reduce the size
    of this 1048576 byte file by 0 percent.
   
    Chi square distribution for 1048576 samples is 221.79, and randomly
    would exceed this value 93.44 percent of the times.
   
    Arithmetic mean value of data bytes is 127.4089 (127.5 = random).
    Monte Carlo value for Pi is 3.143658232 (error 0.07 percent).
    Serial correlation coefficient is 0.001572 (totally uncorrelated = 0.0).

FreeDOS
=======

C:\NOISE>busy.bat
C:\NOISE>sample.exe noise.dat 1048576 -ar

Repeat this hundreds of times until noise.dat reaches the desired size.

C:\ENT>ent <C:\NOISE\NOISE.DAT

    Entropy = 7.999855 bits per byte.
   
    Optimum compression would reduce the size
    of this 1048576 byte file by 0 percent.
   
    Chi square distribution for 1048576 samples is 211.27, and randomly
    would exceed this value 97.88 percent of the times.
   
    Arithmetic mean value of data bytes is 127.5550 (127.5 = random).
    Monte Carlo value for Pi is 3.146267495 (error 0.15 percent).
    Serial correlation coefficient is 0.000964 (totally uncorrelated = 0.0).