Chess(GNU) Chess(GNU)
NAME
Chess - GNU Chess
SYNOPSIS
Chess [ arg1 arg2 ]
DESCRIPTION
Chess plays a game of chess against the user or it plays
against itself.
Chess has a simple alpha-numeric board display or it can
be compiled for use with the CHESSTOOL program on a SUN
workstation. The program gets its opening moves from the
file gnuchess.book which should be located in the same
directory as gnuchess. To invoke the prgram, type
'gnuchess' or type 'chesstool gnuchess' on a SUN worksta-
tion where 'CHESSTOOL' is installed. The 'gnuchess' com-
mand can be followed by up to 2 command line arguments.
If one argument is given it determines the programs search
time in seconds. If two arguments are given, they will be
used to set tournament time controls with the first argu-
ment being the number of moves and the second being the
total clock time in minutes. Thus, entering 'chess 60 5'
will set the clocks for 5 minutes (300 seconds) for the
first 60 moves. If no argument is given the program will
prompt the user for level of play. For use with
CHESSTOOL, see the documentation on that program.
Once Chess is invoked, the program will display the board
and prompt the user for a move. To enter a move, use the
notation 'e2e4' where the first letter-number pair indi-
cates the origination square and the second letter-number
pair indicates the destination square. An alternative is
to use the notation 'nf3' where the first letter indicates
the piece type (p,n,b,r,q,k). To castle, type the origin
and destination squares of the king just as you would do
for a regular move, or type "o-o" for kingside castling
and "o-o-o" for queenside.
COMMANDS
In addition to legal moves, the following commands are
available as responses.
beep -- causes the program to beep after each move.
bd -- updates the current board position on the display.
book -- turns off use of the opening library.
both -- causes the computer to play both sides of a chess
game.
black -- causes the computer to take the black pieces with
the move and begin searching.
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Chess(GNU) Chess(GNU)
level -- allows the user to set time controls such as 60
moves in 5 minutes etc. In tournament mode, the program
will vary the time it takes for each move depending on the
situation. If easy mode is disabled (using the 'easy'
command), the program will often respond with its move
immediately, saving time on its clock for use later on.
depth -- allows the user to change the search depth of the
program. The maximum depth is 29 ply. Normally the depth
is set to 29 and the computer terminates its search based
on elapsed time rather than depth. Using the depth com-
mand allows setting depth to say 4 ply and setting
response time to a large number such as 9999 seconds. The
program will then search until all moves have been exam-
ined to a depth of 4 ply (with extensions up to 11 addi-
tional ply for sequences of checks and captures).
easy -- toggles easy mode (thinking on opponents time) on
and off. The default is easy mode ON. If easy mode is
disabled, the user must enter a 'break' or '^C' to get the
programs attention before entering each move.
edit -- allows the user to set up a board position. In
this mode, the '#' command will clear the board, the 'c'
command will toggle piece color, and the '.' command will
exit setup mode. Pieces are entered by typing a letter
(p,n,b,r,q,k) for the piece followed by the coordinate.
For example "pb3" would place a pawn on square b3.
force -- allows the user to enter moves for both sides. To
get the program to play after a sequence of moves has been
entered use the 'white' or 'black' commands.
get -- retrieves a game from disk. The program will
prompt the user for a file name.
help -- displays a short description of the commands.
hint -- causes the program to supply the user with its
predicted move.
list -- writes the game moves and some statistics on
search depth, nodes, and time to the file 'chess.lst'.
new -- starts a new game.
post -- causes the program to display the principle varia-
tion and the score during the search. A score of 100 is
equivalent to a 1 pawn advantage for the computer.
random -- causes the program to randomize its move selec-
tion slightly.
reverse -- causes the board display to be reversed. That
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Chess(GNU) Chess(GNU)
is, the white pieces will now appear at the top of the
board.
quit -- exits the game.
save -- saves a game to disk. The program will prompt the
user for a file name.
switch -- causes the program to switch places with the
opponent and begin searching.
undo -- undoes the last move whether it was the computer's
or the human's. You may also type "remove". This is equiv-
alent to two "undo's" (e.g. retract one move for each
side).
white -- causes the computer to take the white pieces with
the move and begin searching.
BUGS
Pawn promotion to pieces other than a queen is not
allowed. En-Passant does not work properly with
CHESSTOOOL. The transposition table may not work properly
in some positions so the default is to turn this off.
SEE ALSO
chesstool(6)
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