Re: Sudoku puzzle solver for Apple II

[pausch@saaf.se (Paul Schlyter)]

In article <XtudnVI15qUVVCnZnZ2dnUVZ_oydnZ2d@comcast.com>,
Michael J. Mahon <mjmahon@aol.com> wrote:
>Scott Hemphill and I recently collaborated to create a Sudoku puzzle
>solver for Apple II computers.  The machine language solver is Scott's,
>with some adaptations by me, and I wrote the interactive Applesoft
>front-end.
>
>SUDOKU runs on any Apple II with 80-column firmware and a 65C02
>processor, which includes the IIc, the IIc+, the Enhanced //e, and
>the IIgs.
>
>It is amazingly fast!  Most Sudoku solvers run on modern PCs thousands
>of times faster than a 1MHz Apple II, and take seconds to solve a
>puzzle,

I don't believe that!  Check out this Sudoku solver:
    http://homepage.ntlworld.com/valleyway/solver.html

It's written in Javascript, which of course is a quite inefficient
programming language - yet it needs less than half a second to solve
a sudoku, on a 4+ year old PC running at a moderate 1.8 GHz clock speed.

You must have encountered some really sloppily written sudoku solvers
for the PC if they required several seconds to solve a sudoku....


> but Scott's solver is so time and space efficient that it
>solves puzzles in seconds *running on an Apple II*!
>
>Check it out at:
>
>http://members.aol.com/mjmahon/Sudoku.html
>
>It is available both as a ShrinkIt disk archive and as a .dsk image.

...but why does it require a 65C02 ?  Couldn't it have been written
in plain 6502 assembly language?


>Enjoy!
>
>(BTW, the execution profile referred to in the paper has not yet
>been uploaded, so for the time being, that's a 404. ;-)
>
>-michael
>
>Fast Sudoku solving for Apple II's!
>Home page:  http://members.aol.com/MJMahon/
>
>"The wastebasket is our most important design
>tool--and it is seriously underused."


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