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Re: Interesting one-line BASIC program

sicklittlemonkey wrote:

On Apr 1, 2:45 am, "Michael J. Mahon" <mjma...@aol.com> wrote:


As you'll see if you Ctl-C out of the loop and examine "I" when
the display stops changing, it takes less than 20000 iterations.



Or one can count it exactly below - emulator recommended! ;-)

10 HGR
20 FOR I = 1 TO 40000
30 OFFSET = 8192 + 8192 * RND(1)
40 IF PEEK(OFFSET) = 0 THEN PERIOD = I
50 POKE OFFSET, 255
60 REM OR TO VISUALISE ENTROPY USE ...
70 REM POKE OFFSET, PEEK(OFFSET) + 1
80 NEXT I
90 PRINT PERIOD

The period seems to be around 38,000 depending on the seed.
(The large variation is strange - I'd pry if I had time.)

Oh, I came across this quite a while back, and again now:
A Better Random Number Generator for Apple's Floating Point BASIC
http://www.kaner.com/pdfs/random.pdf


I've written to him for the full paper, including implementation.

There have been several such papers published over the years,
including at least one in Call-A.P.P.L.E.

One well-known problem with RND is the incomplete seeding at
coldstart time, but apparently it's bad regardless of seeding...

I wonder how many Monte Carlo simulations on Apples have
been tainted by this bug?  ;-)

-michael

NadaPong: Network game demo for Apple II computers!
Home page:  http://members.aol.com/MJMahon/

"The wastebasket is our most important design
tool--and it's seriously underused."