.TH ADVENTURE 6 .SH NAME gnuchess \- The Technology Chess Program for GNU Unix .SH SYNOPSIS .B gnuchess [ .BI \-n ] .SH DESCRIPTION .I Chess plays a game of chess against the user. Or it plays against itself. Or it referees a game. .PP .I Chess has two display modes. The first mode is simply a normal mode that you could use with a terminal. The second mode is a fancy display mode you can use with a SUN workstation. To use the former, simply type 'gnuchess'. To use the latter, simply type 'chesstool gnuchess' on a SUN workstation where 'chesstool' is installed. In the latter example, the argument should be the path specifying where to find the gnuchess binary. .PP The following documentation assumes you are in the first mode (e.g. normal mode using a regular terminal). If not, then you should read the chesstool documentation. .PP For help once in .I Chess type a question-mark. To type in your move, use the notation "e2e4" where the first letter-number pair indicates the origination square and the second letter-number pair indicates the destination square. The letter indicates the column with the left-most column being "a" and the right-most column being "h". The number indicates the row, the first row (White's first rank) being "1" and the last row (Black's first rank) being "8". To castle, type the origin square of the king and the destination square of the king, just as you would do for a regular move. .PP The "bd" command prints what the current board position looks like. You may type this to see what the board looks like after the computer moves. .PP The "book" command compiles the opening book into dbm(3) format. This book is then consulted whenever the computer makes a move. If the current position is in the book, then the suggested move associated with that position will be made as the computer's move. Note that this command is a maintenance command, usually used only once per site per book. .PP The "depth" command allows the user to change how many moves ahead the computer looks. Normally, it looks ahead three half-moves, examining every move for each side. Then, it examines all captures for both sides for another two half-moves. "Depth" changes the first of these values. There is an upper boundary of five half-moves as set by the quiescence search which searches captures a little deeper to get better tactical play. .PP The "enter" command causes the current game played thus far to be entered in the human-readable version of the opening book. If no current game is in progress, this command requests the name of a file from which to read games. These are then added to the binary database. Since the versions of the two files are slightly different, in the former case, you must additionally type "book" to get the new game fully entered in the book. Also, the "enter" command tries to mail your new additions to the book maintainers so that your contributions can be added to the master copy of the book. If you are not on our network, you should send us your new additions via some other method. .PP "Fill" allows the user to specify a completely different board position. Input is based on Forsythe notation. For example, the opening position in Forsythe notation is "rnbqkbnrpppppppp8888PPPPPPPPRNBQKBNR+". Capital letters indicate a White piece, lower-case Black. A plus means it is White's move, a minus means Black's. .PP "History" and "historyf" list the game as played so far to the terminal and a file respectively. The file is assumed to be "GAMES/chXXXXXX" where XXXXXX is a random number and GAMES is a subdirectory. If GAMES does not exist, an error message is reported. The equivalent of "historyf" is done after every move automatically to record the game thus far. .PP "Legals" shows legal moves for the current position along with the rating for each move based on a positional presort. .PP "Neither" instructs the program to play neither side, that is, to simply act as a referee. .PP "Reset" resets the board to the starting position. .PP "Quit" exits the game. .PP "Read" restores a game as if you were still playing it. The game must be in the format as written by "historyf" or as automatically recorded by the program itself after every move. .PP "Self" causes the program to play against itself. .PP "Static" causes a static evaluation to be done for the current position. A static evaluation is based on material difference only. Positional considerations are handled by the ply-1 positional presort. .PP "Switch" causes the program to move, whether or not it is the program's turn to do so. Continually typing "switch" is equivalent to typing "self". .PP "Test-moves" initiates a test of the speed of the move generator. An initial series of move generations is done for the opening position and the timing speed is reported. Then, for each of ten stored test positions, a series of move generations is done and the timing speed is reported for each one. Finally, the program averages across those ten runs and reports the overall average. .PP "Test-search" uses the ten stored test positions to actually conduct a search at the current depth to choose a move for each position. .PP "Undo" undoes the last move whether it was the computer's or the human's. You may also type "remove". This is equivalent to two "undo's" (e.g. retract one move for each side). .PP The flag-option on the command line allows specification of how deep to search in half-moves as with 'Chess -3' to search three half-moves ahead. Capture searches are normally carried out a few half-moves further than the regular full search specified with this option. This is known as the quiescence search and it usually is conducted to 6 ply. This option is identical to the "depth" command once in the program. .SH BUGS .PP En passant is not currently implemented. Also, promotion to pieces other than queens is disallowed. Checks and checkmates are not detected in the tree-search and are not handled as "forcing" variations. .PP There are other bugs. Suggestions for improvements and caveats are contained in the files README and TODO which come with this distribution. .SH AUTHOR .nf Stuart Cracraft Stuart Cracraft P.O. Box 13123 UCLA, Dept. of Mathematics Torrance, Ca. Los Angeles, Ca. 90503 90024 (213) 214-1136 (213) 825-9040 .fi .SH AUTHOR'S COMMENT .PP This software is being made available by the Free Software Foundation under the restrictions described in its license agreement which accompanies this distribution. This software, its sources, binaries, documentation and all associated parts are copyright (C) 1986 by the Free Software Foundation, Inc. .SH SEE ALSO .nf chesstool(6) dbm(3) .fi