CHESS(6)CHESS(6)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 program, type
'gnuchess' or type 'chesstool gnuchess' on a SUN workstation where
'CHESSTOOL' is installed. The 'gnuchess' command 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 argument
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 pro‐
gram 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 indicates the origination square and the sec‐
ond letter-number pair indicates the destination square. An alterna‐
tive 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.
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 dis‐
abled (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 command 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 examined to a depth of 4 ply
(with extensions up to 11 additional 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 pro‐
gram 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 variation 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 selection slightly.
reverse -- causes the board display to be reversed. That 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 equivalent 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.
GNU December 30, 1993 CHESS(6)
