xboard(6)

NAME
xboard - X user interface for GNU Chess, the Internet Chess Server (ICS), and electronic mail correspondence chess.

SYNOPSIS
To run with GNU Chess: xboard [options]
To run with the ICS: xboard -ics [options]
To play email chess: See cmail(6).
To run standalone: xboard -ncp [options]

DESCRIPTION
xboard is a graphical chessboard that can serve as a user interface for GNU Chess, for the Internet Chess Server, or for electronic mail correspondence chess. xboard can also be used by itself.

As an interface to GNU Chess, xboard lets you play a game against the machine, set up arbitrary positions, force variations, or watch a game between two machines.

As an interface to the Internet Chess Server (ICS), xboard -ics lets you play against other ICS users, observe games they are playing, or review games that have recently finished.

As an interface to electronic mail correspondence chess, xboard works with the cmail(6) program. See its manual page for instructions.

You can also use xboard as a chessboard to play through games. It will read and write game files and allow you to play through variations manually. You can use it to browse games off the net or review GNU Chess, ICS, and correspondence games you have saved. These features are available at all times; even if you do not have access to GNU Chess or the ICS, you can use them by giving the command xboard -ncp.

After starting xboard, you make moves by dragging pieces with the mouse. Press mouse button 1 while the cursor is on one of your pieces, then move the cursor to another square and release the button.

When xboard is iconized, its graphical icon is a white knight if it is White's turn to move, a black knight if it is Black's turn. (See Iconize below if you have problems getting this feature to work.)

OPTIONS
Most of the xboard options have both a long name and a short name. To turn a boolean option on or off from the command line, either give its long name followed by the value True or False (-longOptionName True), or give just the short name to turn the option on (-opt), or the short name preceded by "x" to turn the option off (-xopt). For options that take strings or numbers as values, you can use the long or short option names interchangeably.

Each option corresponds to an X resource with the same name, so you can set options in your .Xdefaults file if you like. For options that have two names, the longer one is the name of the corresponding X resource; the short name is not recognized in .Xdefaults. To turn a boolean option on or off in your .Xdefaults file, give its long name followed by the value True or False (XBoard*longOptionName: True).

GNU Chess Options

-tc or -timeControl minutes[:seconds]
-mps or -movesPerSession moves
    Each player begins with the specified amount of time on his clock. If a player makes the specified number of moves before his clock runs out, xboard adds the specified amount of time to his clock. Default: 40 moves in 5 minutes.

-clock or -clockMode
    Determines whether or not to display the chess clocks. If clockMode is False, the clocks are not shown, but the side that is to play next is still highlighted. Also, unless searchTime or searchDepth is set, GNU Chess still keeps track of the clock time and uses it to determine how fast to make its moves.

-st or -searchTime minutes[:seconds]
    Tells GNU Chess to spend at most the given amount of time searching for each of its moves. Without this option, GNU Chess chooses its search time based on the number of moves and amount of time remaining until the next time control. Setting this option also sets clockMode to False.

-sd or -searchDepth number
    Tells GNU Chess to look ahead at most the given number of moves when searching for a move to make. Without this option, GNU Chess chooses its search depth based on the number of moves and amount of time remaining until the next time control. Setting this option also sets clockMode to False.

-thinking or -showThinking
    If this option is set, GNU Chess's notion of the score and best line of play from the current position is displayed as it is thinking. The score indicates how many pawns ahead (or if negative, behind) GNU Chess thinks it is. In matches between two machines, the score is prefixed by W or B to indicate whether it is showing White's thinking or Black's.

-mm or -matchMode
    Automatically runs a game between two chess programs. If the loadGameFile or loadPositionFile option is set, xboard starts the game with the given opening moves or the given position; otherwise, the game starts with the standard initial chess position. If the saveGameFile option is set, a move record for the match is appended to the specified file. If the savePositionFile option is set, the final position reached in the match is appended to the specified file. When the match is over, xboard exits. Default: False.

-fcp or -firstChessProgram program
    Name of first chess program. In matches between two machines, this program plays Black. Default: "gnuchessx".

-scp or -secondChessProgram program
    Name of second chess program, if needed. In matches between two machines, this program plays White; otherwise it is not started. Default: "gnuchessx".

-fh or -firstHost host
-sh or -secondHost host
    Hosts on which the chess programs are to run. The default for each is "localhost". If you specify another host, xboard uses rsh(1) to run the chess program there. (You can substitute a different remote shell program for rsh using the remoteShell option described below.)

-initString string
    The string that is sent to initialize the chess program. Default: "new\nbeep\nrandom\neasy\n". If you change this option, don't remove the "new" and "beep" commands. You can remove the "random" command if you like; including it causes GNU Chess to randomize its move selection slightly so that it doesn't play the same moves in every game. (Even without "random", GNU Chess randomizes its choice of moves from its opening book.) You can also remove "easy" if you like; including it toggles easy mode off, causing GNU Chess to think on your time. That is, if "easy" is included in the initString, GNU Chess thinks on your time; if not, it does not. (Yes, this does seem backwards, doesn't it!) You can also try adding other commands to the initString; see the GNU Chess documentation for details.

-whiteString string
-blackString string
    These options control what is sent when the Machine White and Machine Black buttons are selected. This is mostly for compatibility with obsolete versions of GNU Chess.

Internet Chess Server Options

-ics or -internetChessServerMode
    Connect with an Internet Chess Server to play chess against its other users, observe games they are playing, or review games that have recently finished. Default: False. To use xboard in ICS mode, run it in the foreground, and use the terminal you started it from to type commands and receive text responses from the chess server. Useful ICS commands include who to see who is logged on, games to see what games are being played, match to challenge another player to a game, observe to observe an ongoing game, examine or oldmoves to review a recently completed game, and of course help. Whenever you ask to observe an ongoing game, review a completed game, or resume an adjourned game, xboard retrieves and parses the list of past moves from the ICS, so you can review them with the Forward and Backward commands or save them with Save Game. Some special xboard features are activated when you are in examine mode on ICS. See the descriptions of the menu commands Forward, Backward, Pause, ICS Client, and Stop Examining below.

-icslogon or -internetChessServerLogonScript file-name
    Whenever xboard connects to the Internet Chess Server, if it finds a file with the name given in this option, it feeds the file's contents to the ICS as commands. The default file name is ".icsrc". Usually the first two lines of the file should be your ICS user name and password. The file can be either in $CHESSDIR, in xboard's working directory if CHESSDIR is not set, or in your home directory.

-autoflag or -autoCallFlag
    If autoCallFlag is True and your opponent runs out of time before you do, xboard will automatically call his flag, claiming a win on time (or a draw if you do not have mating material). Default: False.

-autobs or -autoObserve
    If autoObserve is True and you add a player to your "gnotify" list on ICS, xboard will automatically observe all of that player's games, unless you are doing something else (such as observing or playing a game of your own) when one starts. Default: False.

-quiet or -quietPlay
    If this option is True, xboard will automatically issue a "set shout 0" command whenever you start an ICS game and a "set shout 1" command whenever you finish one. Default: False.

-icshost or -internetChessServerHost host
    The Internet host name or address of the chess server to connect to when in ICS mode. Default: chess.lm.com. See the file "ics-addresses" in the xboard source distribution for a list of other addresses to try. See also the output of the command "finger chess@ics.onenet.net". If your site doesn't have a working Internet name server, try specifying the host address in numeric form. The address for chess.lm.com is 192.231.221.16.

-icsport or -internetChessServerPort port-number
    The port number to use when connecting to a chess server in ICS mode. Default: 5000.

-gateway host-name
    If this option is set to a host name, xboard uses rsh(1) to run the telnet(1) program on the given host to communicate with the Internet Chess Server instead of opening a direct TCP connection. (You can substitute a different remote shell program for rsh using the remoteShell option described below.) This option is useful if your machine is unable to connect directly to the ICS but is able to rsh to a gateway host that can connect to the ICS. As an example, suppose the gateway host is called gate.ralph.com, and you set options as follows:
        xboard -ics -gateway gate.ralph.com -icshost chess.lm.com
    Or in your .Xdefaults file:
        XBoard*gateway: gate.ralph.com
        XBoard*internetChessServerHost: chess.lm.com
    Then when you run xboard in ICS mode, it will connect to the ICS by using rsh to run the command "telnet chess.lm.com 5000" on host gate.ralph.com.

-telnet or -useTelnet
    If this option is set to True, xboard runs the telnet(1) program to communicate with the Internet Chess Server. If the option is False (the default), xboard opens a TCP socket to communicate with the ICS. One case where this option is useful is if your machine cannot connect directly to the ICS, but can telnet to a gateway host that can connect to the ICS. It is more general than the gateway option, because you may be able to telnet to a host that you cannot rsh to, but it's not as convenient to use. As an example, suppose the gateway host is called gate.ralph.com, and you set command-line options as follows:
        xboard -ics -telnet -icshost gate.ralph.com -icsport 23
    Or in your .Xdefaults file:
        XBoard*useTelnet: true
        XBoard*internetChessServerHost: gate.ralph.com
        XBoard*internetChessServerPort: 23
    Then when you run xboard in ICS mode, you will be prompted to log in to the gateway host. Then telnet to ICS (using a command like telnet chess.lm.com 5000"). See also LIMITATIONS below. The recipe above works because the option "-icsport 23" causes xboard to connect to the gateway host's standard incoming telnet service (port 23) instead of trying to connect to a chess server running on the gateway host (port 5000).

-telnetProgram prog-name
    This option gives the name of the telnet program to be used with the gateway and useTelnet options. The default is "telnet". The telnet program is invoked with the value of internetChessServerHost as its first argument and the value of internetChessServerPort as its second argument. One case where this option is useful is if your machine cannot make a direct TCP connection to the ICS but can telnet there through a proxy server. As an example, suppose that your proxy telnet program is called ptelnet. You should then set command-line options as follows:
        xboard -ics -telnet -telnetProgram ptelnet
    Or in your .Xdefaults file:
        XBoard*useTelnet: true
        XBoard*telnetProgram: ptelnet
    Then when you run xboard in ICS mode, it will issue the command "ptelnet chess.lm.com 5000" to connect to the ICS.

-internetChessServerCommPort or -icscomm dev-name
    If this option is set, xboard communicates with the ICS through the given character I/O device instead of opening a TCP connection. Use this option if your system does not have any kind of Internet connection itself (not even a SLIP or PPP connection), but you do have dialup access (or a hardwired terminal line) to an Internet service provider from which you can telnet to the ICS. The support for this option in xboard is minimal. You need to set all communication parameters and tty modes before you enter xboard. Use a script something like this:
        stty raw -echo 9600 > /dev/tty00
        xboard -ics -icscomm /dev/tty00
    Here replace "/dev/tty00" with the name of the device that your modem is connected to. You might have to add several more options to these stty commands. See the man pages for stty(1) and tty(4) if you run into problems. Also, on many systems stty works on its standard input instead of standard output, so you have to use "<" instead of ">". If you are using linux, try starting with the script below. Change it as necessary for your installation.
        ####################################################
        #!/bin/sh -f
        # configure modem and fire up xboard
        # configure modem
        (
        stty 2400 ; stty raw ; stty hupcl ; stty -clocal
        stty ignbrk ; stty ignpar ; stty ixon ; stty ixoff
        stty -iexten ; stty -echo
        ) < /dev/modem
        xboard -ics -icscomm /dev/modem
        ####################################################
    After you start xboard in this way, type whatever commands are necessary to dial out to your Internet provider and log in. Then telnet to ICS (using a command like "telnet chess.lm.com 5000"). See also LIMITATIONS below.

Load and Save Options

-lgf or -loadGameFile file
-lgi or -loadGameIndex index
    If the loadGameFile option is set, xboard loads the specified game file at startup. The file name "-" specifies the standard input. If the loadGameIndex option is set to N, the Nth game found in the file is loaded; otherwise the first game is loaded.

-td or -timeDelay seconds
    Time delay between moves during "Load Game". Fractional seconds are allowed; try -td 0.4. A time delay value of -1 tells xboard not to step through game files automatically. Default: 1 second.

-sgf or -saveGameFile file
    If this option is set, xboard appends a record of every game played to the specified file. The file name "-" specifies the standard output.

-autosave or -autoSaveGames
    If this option is True, at the end of every game xboard prompts you for a file name and appends a record of the game to the file you specify. Ignored if saveGameFile is set.

-lpf or -loadPositionFile file
-lpi or -loadPositionIndex index
    If the loadPositionFile option is set, xboard loads the specified position file at startup. The file name "-" specifies the standard input. If the loadPositionIndex option is set to N, the Nth position found in the file is loaded; otherwise the first position is loaded.

-spf or -savePositionFile file
    If this option is set, xboard appends the final position reached in every game played to the specified file. The file name "-" specifies the standard output.

-oldsave or -oldSaveStyle
    If this option is False (the default), xboard saves games in PGN (portable game notation) and positions in FEN (Forsythe-Edwards notation). If the option is True, a save style that is compatible with older versions of xboard is used instead.

User Interface Options

standard Xt options
    xboard accepts standard Xt options like -display, -geometry, and -iconic.

-bell or -ringBellAfterMoves
    If this option is True, xboard alerts you by ringing the terminal bell after each of your opponent's moves (or after every move if you are observing a game on the Internet Chess Server). The bell is not rung after moves you make or moves read from a saved game file. Default: False. If you turn on this option when using xboard with the Internet Chess Server, you will probably want to give the "set bell 0" command to the ICS, since otherwise the ICS will ring the bell itself after every move (not just yours).

-queen or -alwaysPromoteToQueen
    If this option is False (the default), xboard brings up a dialog box whenever you move a pawn to the last rank, asking what piece you want to promote it to. If the option is True, your pawns are always promoted to queens. (Your opponent can still underpromote, however.)

-size or -boardSize (Large | Medium | Small)
    Determines how large the board will be and what built-in piece bitmaps will be used. On a large board (the default), pieces are 80x80 pixels, on a medium board 64x64 pixels, and on a small board 40x40 pixels.

-coords or -showCoords
    If this option is True, xboard displays algebraic coordinates along the board's left and bottom edges. The default is False. The coordFont option specifies what font to use.

-flip or -flipView
    If you are playing a game on the ICS, the board is always oriented at the start of the game so that your pawns move from the bottom of the window towards the top. Otherwise, the starting is determined by the flipView option; if it is False (the default), White's pawns move from bottom to top at the start of each game; if it is True, Black's pawns move from bottom to top.

-title or -titleInWindow
    If this option is True, xboard displays player names (for ICS games) and game file names (for Load Game) inside its main window. If the option is False (the default), this information is displayed only in the window banner. You probably won't want to set this option unless the information is not showing up in the banner, as happens with a few X window managers.

-mono or -monoMode
    Determines whether xboard displays its pieces and squares with two colors (True) or four (False). You shouldn't have to specify monoMode; xboard will determine if it is necessary.

-borderXoffset
-borderYoffset
    These options are part of a kludge that helps position the Comment and Edit Comment windows in the same place on the screen when they are closed and reopened. They should be set equal to the width and height of the borders that your X window manager adds to windows when it displays them. The defaults are correct for tvtwm(1).

-clockFont
    The font used for the clocks. If the option value is a pattern that does not specify the font size, xboard tries to choose an appropriate font for the board size being used. Default: -*-helvetica-bold-r-normal--*-*-*-*-*-*-*-*.

-coordFont
    The font used for rank and file coordinate labels if showCoords is True. If the option value is a pattern that does not specify the font size, xboard tries to choose an appropriate font for the board size being used. Default: -*-helvetica-bold-r-normal--*-*-*-*-*-*-*-*.

-font
    The font used for popup dialogs, menus, comments, etc. Default: -*-helvetica-medium-r-normal--14-*-*-*-*-*-*-*.

-bitmapDirectory or -bm
    By default, xboard uses a set of compiled-in bitmaps for its pieces. If the bitmapDirectory option is set at runtime, piece bitmaps are taken from files in the specified directory instead. The first character of a bitmap name gives the piece it represents (p, n, b, r, q, or k); the next characters give the size in pixels (80, 64, or 40), and the following character indicates whether the piece is solid or outline (s or o). Bitmap file names have the extension ".bm". The outline bitmaps are used only in monochrome mode. Two sets of bitmaps are distributed with xboard. Those in the directory bitmaps are normally compiled in as the default. Those in the bitmaps.xchess directory can be selected at runtime with the bitmapDirectory option. If you want to compile in the latter set as the default, rename the bitmaps directory to "bitmaps.fselch" and the bitmaps.xchess directory to "bitmaps"; then recompile xboard.

-whitePieceColor
    Color specification for white pieces, suitable for XParseColor(3X11). Default: #FFFFCC. These colors look good on a DEC workstation. If you need different colors, try using the xcolors application. Source for xcolors can be found in the X11 contrib directory.

-blackPieceColor
    Same for black pieces. Default: #202020.

-lightSquareColor
    Same for light squares. Default: #C8C365.

-darkSquareColor
    Same for dark squares. Default: #77A26D.

If you are using a grayscale monitor, try setting the colors to:
    -whitePieceColor     gray100
    -blackPieceColor     gray0
    -lightSquareColor    gray80
    -darkSquareColor     gray60

Other Options

-ncp or -noChessProgram
    If this option is True, xboard acts as a passive chessboard; it does not start a chess program at all. Turning on this option also turns off clockMode. Default: False.

-debug or -debugMode
    Turns on debugging printout.

-rsh or -remoteShell shell-name
    Name of the command used to run programs remotely. The default is "rsh" or "remsh", determined when xboard is configured and compiled.

-ruser or -remoteUser user-name
    User name on the remote system when running programs with the remoteShell. The default is your local user name.

MENU COMMANDS, BUTTONS, AND KEYS
All xboard commands are available on menus. The most frequently used commands also have shortcut keys or on-screen buttons.

File Menu

Reset
    Resets xboard and GNU Chess to the beginning of a new chess game. The "r" key is a keyboard equivalent. In Internet Chess Server mode, clears the current state of xboard, then resynchronizes with ICS by sending a refresh command. If you want to stop playing, observing, or examining a game on ICS, use an appropriate command from the Action menu, not Reset.

Load Game
    Plays a game from a record file. A popup dialog prompts you for the file name. If the file contains more than one game, and you want to load the Nth one, type the number N after the file name, separated by a space. The "g" key is a keyboard equivalent. The game file parser will accept PGN (portable game notation), or in fact almost any file that contains moves in algebraic notation. If the file includes a PGN position (FEN tag), or an xboard position diagram bracketed by "[--" and "--]" before the first move, the game starts from that position. Text enclosed in parentheses, square brackets, or curly braces is assumed to be commentary and is displayed in a pop-up window. Any other text in the file is ignored. PGN variations (enclosed in parentheses) are treated as comments; xboard is not able to walk variation trees.

Load Next Game
    Loads the next game from the last game record file you loaded. The shifted "N" key is a keyboard equivalent.

Load Previous Game
    Loads the previous game from the last game record file you loaded. The shifted "P" key is a keyboard equivalent.

Reload Same Game
    Reloads the last game you loaded.

Load Position
    Sets up a position from a position file. A popup dialog prompts you for the file name. If the file contains more than one saved position, and you want to load the Nth one, type the number N after the file name, separated by a space. Position files must be in FEN (Forsythe-Edwards notation), or in the format that the Save Position command writes when oldSaveStyle is turned on.

Save Game
    Appends a record of the current game to a file. A popup dialog prompts you for the file name. If the game did not begin with the standard starting position, the game file includes the starting position used. Games are saved in the PGN (portable game notation) format, unless the oldSaveStyle option is True, in which case they are saved in an older format that is specific to xboard. Both formats are human-readable, and both can be read back by the Load Game command.

Save Position
    Appends a diagram of the current position to a file. A popup dialog prompts you for the file name. Positions are saved in FEN (Forsythe-Edwards notation) format unless the oldSaveStyle option is True, in which case they are saved in an older, human-readable format that is specific to xboard. Both formats can be read back by the Load Position command.

Mail Move
Reload CMail Message
    See the manual page for cmail(6).

Exit
    Exits from xboard. The "q" key is a keyboard equivalent.

Mode Menu

Pause
    Pauses updates to the board, and if you are playing against GNU Chess, also pauses your clock. To continue, select Pause again, and the display will automatically update to the latest position. The [P] button and keyboard "p" key are equivalents. If you select Pause when you are playing against GNU Chess and it is not your move, GNU Chess's clock will continue to run and it will eventually make a move, at which point both clocks will stop. Since board updates are paused, however, you will not see the move until you exit from Pause mode (or select Forward). This behavior is meant to simulate adjournment with a sealed move. If you select Pause while you are in examine mode on ICS, you can step backward and forward in the current history of the examined game without affecting the other observers and examiners. Select Pause again to reconnect yourself to the current state of the game on ICS. If you select Pause while you are loading a game, the game stops loading. You can load more moves manually by selecting Forward, or resume automatic loading by selecting Pause again.

Edit Comment
    Adds or modifies a comment on the current position. Comments are saved by Save Game and are displayed by Load Game, Forward, and Backward.

Machine White
    Forces GNU Chess to play White. GNU Chess mode only.

Machine Black
    Forces GNU Chess to play Black. GNU Chess mode only.

Two Machines
    Plays a game between two computer programs. GNU Chess mode only.

ICS Client
    ICS mode only. Takes xboard out of the Edit Game or Edit Position state. While you are examining a game on the ICS, you can issue the ICS position-editing commands with the mouse. (Do this with ICS Client selected on the Mode menu, not Edit Position; the latter edits only your local copy of the position.) To drop a new piece on a square, press mouse button 2 or 3 over the square. This brings up a menu of white pieces (button 2) or black pieces (button 3). Additional menu choices let you empty the square or clear the board. You cannot set the side to play or drag pieces to arbitrary squares while examining on ICS, however; the ICS permits only legal moves in this mode.

Edit Game
    Allows you to make moves for both Black and White, and to change moves after backing up with the Backward command. The clocks do not run. In GNU Chess mode, GNU chess continues to check moves for legality but does not participate in the game. You can bring GNU Chess back into the game by selecting Machine White, Machine Black, or Two Machines. In ICS mode, the moves are not sent to the ICS: Edit Game takes xboard out of ICS Client mode and lets you edit games locally. If you want to edit games on ICS in a way that other ICS users can see, use the ICS examine command or start an ICS match against yourself.

Edit Position
    Lets you set up an arbitrary board position. Use mouse button 1 to drag pieces to new squares, or to delete a piece by dragging it off the board or dragging an empty square on top of it. To drop a new piece on a square, press mouse button 2 or 3 over the square. This brings up a menu of white pieces (button 2) or black pieces (button 3). Additional menu choices let you empty the square or clear the board. You can set the side to play next by clicking on the White or Black indicator at the top of the screen. Selecting Edit Position causes xboard to discard all remembered moves in the current game. In ICS mode, changes made to the position by Edit Position are not sent to the ICS: Edit Position takes xboard out of ICS Client mode and lets you edit positions locally. If you want to edit positions on ICS in a way that other ICS users can see, use the ICS examine command, or start an ICS match against yourself. (See also the ICS Client topic above.)

Action Menu

Accept
    Accepts a pending match offer. If there is more than one offer pending, you will have to type in a more specific command instead of using this menu choice. (ICS mode only)

Decline
    Declines a pending offer (match, draw, adjourn, etc.). If there is more than one offer pending, you will have to type in a more specific command instead of using this menu choice. (ICS mode only)

Call Flag
    Calls your opponent's flag, claiming a win on time, or claiming a draw if you are both out of time. You can also call your opponent's flag by clicking on his clock or by pressing the keyboard "t" key.

Draw
    Offers a draw to your opponent, accepts a pending draw offer from your opponent, or claims a draw by repetition or the 50-move rule, as appropriate. The "d" key is a keyboard equivalent. (Not available in GNU Chess mode.)

Adjourn
    Asks your opponent to agree to adjourning the current game, or agrees to a pending adjournment offer from your opponent. (ICS mode only)

Abort
    Asks your opponent to agree to aborting the current game, or agrees to a pending abort offer from your opponent. An aborted game ends immediately without affecting either player's rating.

Resign
    Resigns the game to your opponent. The shifted "R" key is a keyboard equivalent.

Stop Observing
    Ends your participation in observing a game, by issuing the ICS observe command with no arguments. (ICS mode only)

Stop Examining
    Ends your participation in examining a game, by issuing the ICS unexamine command. (ICS mode only)

Step Menu

Backward
    Steps backward through a series of remembered moves. The [<] button and the "b" key are equivalents. In most modes, Backward only lets you look back at old positions; it does not retract moves. This is the case if you are playing against GNU Chess, playing or observing a game on the ICS, or loading a game. If you select Backward in any of these situations, you will not be allowed to make a different move. Use Retract Move or Edit Game if you want to change past moves. If you are examining a game on ICS, the behavior of Backward depends on whether xboard is in Pause mode. If Pause mode is off, Backward issues the ICS backward command, which backs up everyone's view of the game and allows you to make a different move. If Pause mode is on, Backward only backs up your local view.

Forward
    Steps forward through a series of remembered moves (undoing the effect of Backward) or forward through a game file. The [>] button and the f key are equivalents. If you are examining a game on ICS, the behavior of Forward depends on whether xboard is in Pause mode. If Pause mode is off, Forward issues the ICS forward command, which moves everyone's view of the game forward along the current line. If Pause mode is on, Forward only moves your local view forward, and it will not go past the position that the game was in when you paused.

Back to Start
    Jumps backward to the first remembered position in the game. The [<<] button and the shifted "B" key are equivalents. In most modes, Back to Start only lets you look back at old positions; it does not retract moves. This is the case if you are playing against GNU chess, playing or observing a game on the ICS, or loading a game. If you select Back to Start in any of these situations, you will not be allowed to make different moves. Use Retract Move or Edit Game if you want to change past moves; or use Reset to start a new game. If you are examining a game on ICS, the behavior of Back to Start depends on whether xboard is in Pause mode. If Pause mode is off, Back to Start issues the ICS backward 999999 command, which backs up everyone's view of the game to the start and allows you to make different moves. If Pause mode is on, Back to Start only backs up your local view.

Forward to End
    Jumps forward to the last remembered position in the game. The [>>] button and the shifted "F" key are equivalents. If you are examining a game on ICS, the behavior of Forward to End depends on whether xboard is in Pause mode. If Pause mode is off, Forward to End issues the ICS forward 999999 command, which moves everyone's view of the game forward to the end of the current line. If Pause mode is on, Forward to End only moves your local view forward, and it will not go past the position that the game was in when you paused.

Revert
    If you are examining a game on ICS and Pause mode is off, issues the ICS command revert.

Truncate Game
    Discards all remembered moves of the game beyond the current position. Puts xboard into Edit Game mode if it was not there already.

Move Now
    Forces GNU Chess to move immediately. (GNU Chess mode only)

Retract Move
    Retracts your last move. In GNU Chess mode, you can do this only after GNU Chess has replied to your move; if GNU Chess is still thinking, use Move Now first. In ICS mode, Retract Move issues the command takeback 1 or takeback 2 depending on whether it is your opponent's move or yours.

Options Menu

Always Queen
    Toggles the alwaysPromoteToQueen option.

Auto Flag
    Toggles the autoCallFlag option.

Auto Observe
    Toggles the autoObserve option.

Auto Save
    Toggles the autoSaveGames option. Disabled if the saveGameFile option is set, as in that case all games are saved to the specified file.

Bell
    Toggles the ringBellAfterMoves option.

Flip View
    Inverts your view of the chess board for the duration of the current game. Starting a new game returns the board to normal. If you are playing a game on the ICS, the board is always oriented at the start of the game so that your pawns move from the bottom of the window towards the top. Otherwise, the starting orientation is determined by the flipView command line option; if it is False (the default), White's pawns move from bottom to top at the start of each game; if it is True, Black's pawns move from bottom to top.

Old Save Style
    Toggles the oldSaveStyle option.

Quiet Play
    Toggles the quietPlay option.

Show Coords
    Toggles the showCoords option.

Show Thinking
    Toggles the showThinking option.

Help Menu

Hint
    Displays a move hint from GNU Chess. GNU Chess mode only.

Book
    Displays a list of possible moves from GNU Chess's opening book. The first column gives moves, the second column gives one possible response for each move, and the third column shows the number of lines in the book that include the move from the first column. If you select this option and nothing happens, GNU Chess is out of its book. GNU Chess mode only.

About Game
    Displays information about the current game, in the form of PGN (portable game notation) tags.

About XBoard
    Shows the current xboard version number.

Other shortcut keys

Iconize
    Pressing the i or c key iconizes xboard. The graphical icon displays a white knight if it is White's move, or a black knight if it is Black's move. If your X window manager displays only text icons, not graphical ones, check its documentation; there is probably a way to enable graphical icons. If you are running the Motif window manager mwm(1), add these lines to your .Xdefaults file and restart mwm:
        Mwm*iconDecoration: activelabel label image
        Mwm*XBoard*iconImageBackground: White
        Mwm*XBoard*iconImageForeground: Black
    The first line above enables graphical icons in mwm; you don't need it if you already have them. The next two lines force the white knights to come out white and the black knights black. Unfortunately these resources can't be set from inside xboard; you have to set them in your .Xdefaults.

You can add (or remove) xboard shortcut keys using the X resource form.translations. Here is an example of what would go in your .Xdefaults file:
    XBoard*form.translations: Shift<Key>?: AboutGameProc() \n \
        <Key>y: AcceptProc() \n \
        <Key>n: DeclineProc() \n \
        <Key>i: NothingProc()
Binding a key to NothingProc makes it do nothing, thus removing it as a shortcut key. The xboard functions that can be bound to keys are: AbortProc, AboutGameProc, AboutProc, AcceptProc, AdjournProc, AlwaysQueenProc, AutoflagProc, AutobsProc, AutosaveProc, BackwardProc, BellProc, BookProc, CallFlagProc, DeclineProc, DrawProc, EditGameProc, EditPositionProc, FlipViewProc, ForwardProc, HintProc, IcsClientProc, LoadGameProc, LoadNextGameProc, LoadPositionProc, LoadPrevGameProc, MachineBlackProc, MachineWhiteProc, MailMoveProc, MoveNowProc, OldSaveStyleProc, PauseProc, QuietPlayProc, QuitProc, ReloadGameProc, ResetProc, ResignProc, RetractMoveProc, RevertProc, SaveGameProc, SavePositionProc, ShowCoordsProc, ShowThinkingProc, StopExaminingProc, StopObservingProc, ToEndProc, ToStartProc, TruncateGameProc, and TwoMachinesProc.

ENVIRONMENT
Game and position files are found in the directory named by the CHESSDIR environment variable. If this variable is not set, the current working directory is used. If CHESSDIR is set, xboard actually changes its working directory to $CHESSDIR, so GNU Chess listing files will be stored there as well.

SEE ALSO
gnuchess(6), cmail(6).

LIMITATIONS
There is no way for two people running copies of xboard to play each other without going through the Internet Chess Server.

The game parser recognizes only algebraic notation.

The internal move legality tester does not look at the game history, so in some cases it misses illegal castling or en passant captures. However, if you attempt such a move when using GNU Chess (or the ICS), it will reject the move, and xboard will undo it and let you try another. Also, FEN positions saved by xboard do not include correct information about whether castling or en passant are legal.

In ICS mode, xboard cannot handle observing (and/or playing) more than one game at a time. It may get confused if you try to do this, though it tries to recover gracefully. Select Reset from the File menu if you have problems.

Your password may get echoed when you log on to the ICS.

If you are connecting to the ICS by running telnet on an Internet provider or firewall host, you may find that each line you type is echoed back an extra time after you hit Return. If your Internet provider is a Unix system, you can probably turn its echo off by typing "stty -echo" after you log in, and/or by typing ^E-Return (control-E followed by the Return key) to the telnet program after you have logged into ICS. It is a good idea to do this if you can, because otherwise the extra echo can occasionally confuse xboard's parsing routines.

The .icsrc file does not work properly when you connect to ICS through a Unix gateway host with useTelnet mode. The Unix login process apparently discards type-ahead.

Some xboard functions may not work with versions of GNU Chess earlier than 4.0, patchlevel 73.

AUTHORS AND CONTRIBUTORS
Tim Mann has been responsible for xboard versions 1.3 through 3.2. Chris Sears and Dan Sears wrote the original xboard; they were responsible for versions 1.0 through 1.2.

Elmar Bartel contributed the new piece bitmaps for version 3.2. Evan Welsh wrote cmail. John Chanak contributed the initial implementation of ICS mode. The color scheme and the old 80x80 piece bitmaps were taken from Wayne Christopher's XChess program.

Send bug reports to <bug-gnu-chess@prep.ai.mit.edu>. Please use the script(1) program to start a typescript, run xboard with the debug option, and include the typescript output in your message. Also tell us what kind of machine and what operating system version you are using. The command "uname -a" will usually tell you this.

COPYRIGHT
Copyright 1991 by Digital Equipment Corporation, Maynard, Massachusetts. Enhancements Copyright 1992-95 Free Software Foundation, Inc.

XBoard's alternative piece bitmaps (bitmaps.xchess) are derived from the bitmaps in the XChess program, which was written and is copyrighted by Wayne Christopher.

The following terms apply to Digital Equipment Corporation's copyright interest in XBoard:

    All Rights Reserved

    Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation, and that the name of Digital not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission.

    DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

The following terms apply to this enhanced version of XBoard distributed by the Free Software Foundation:

    This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

    This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

    You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.