Category Archives: chessbox

GNU Chess Bugs

After porting GNU Chess from C to Java a few months ago, I reported a few bugs and suspicious code to the GNU Chess mailing list. I’ve finally gotten around to making a bug write-up on this site.

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XBoard and GNU4J

I realized I could run XBoard on my Mac within X11 and let it talk to chessbox_gnu4j via the command line Continue reading

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Exploring Minimax

I’ve been playing around with the GNU Chess code trying to understand the minimax algorithm and its alpha-beta pruning. The pruning offers a chance for a huge optimization if you can immediately refute candidate moves. Unforunately, refuting a move often … Continue reading

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Introducing Chessbox

My Java port of GNU Chess is now available at a new domain name www.chessbox.org, which is just a redirect to www.forthgo.com/chessbox/. The tagline for chessbox is “a collection of chess pieces” allowing it to be a home for various … Continue reading

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Predictable Randomness

One GNU Chess source file I didn’t port to Java was the random number generator, and that turned out to be a problem for processing the binary opening book files. The board position hash codes are 64-bit numbers created by … Continue reading

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“Jnuchess” Plays and Wins

The Java port of GNU Chess is now doing well enough to play a game and beat me. To get the main alpha-beta engine to work I had to track down about a half-dozen or so translation errors I had … Continue reading

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GNU Chess/Java Starts to Run

I decided to go ahead and convert the remaining printf() calls (too chicken to try switching to Java 5 at this point) and ignore the signal() calls so I could try running GNU Chess/Java. The signal() calls are only used … Continue reading

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