1680X Chess Computer  (600-2428)     Operation         Faxback Doc. # 6782

TURNING THE GAME BOARD ON OR OFF

Switch I/O to I to turn on the game board for a new game or to return to a
saved game.  Switch I/O to O to save the game and turn off the computer.
The computer stores all game positions and any next-move calculations it
was computing.

Notes:  To save game information, you must install batteries in the
        computer even if you are using an optional AC adapter.

        If the computer was calculating a move when you turned it off, but
        had not yet completed its calculations, it resumes its
        calculations when you turn it back on.

TURNING THE SOUND ON OR OFF

The computer's sound is normally on.  To turn the computer's sound off,
press COACH LEVEL until the computer beeps once.  Then the file board
light next to H (SILENT) lights for about 2 seconds.  To turn the sound
back on, press COACH LEVEL until the file board light next to G (NORMAL)
lights for about 2 seconds.

Notes:  You can turn the computer's sound on or off any time during a
        game.

        If you turn the computer's sound off, it does not beep even when
        you make an illegal move.

STORING/REMOVING GAME PIECES

1.  Press down on the piece storage compartment cover's arrow, then
    slide the cover in the direction of the arrow.

2.  Lift and remove the cover.

3.  Remove or replace the pieces in the compartment.

4.  Replace the cover.

ADJUSTING THE DISPLAY CONTRAST

Switch I/O to I, then slide IIIII on the back of the computer to the left
or right to adjust the LCD display's contrast.

STARTING A NEW GAME

Press NEW GAME to start a new game and erase any game stored in memory.

Note:  The computer always starts a new game with you playing white pieces
       and your opponent playing black pieces.

PLAY LEVELS

When you play against the computer, you can select a level that matches
your skill.  You can also select from numerous time-controlled play
levels, including several that simulate tournament play.  Some of the
levels let you use the computer to analyze chess problems.

There are 64 different play levels.

These include:  39 standard levels (A1 (L-1A) through E7 (L-8d))

                1 indefinite response time level (E8 (L-1n))

                7 fixed depth levels (F1 (L-d1) through F7 (L-d7))

                1 puzzle level (F8 (L-Pu))

                8 fun levels (G1 (L-F1) through G8 (L-F8))

                4 handicap levels (H1 (L-H1) through H4 (L-H4))

                4 mate search levels (H5 (L-P1) through H8 (L-P4))

The computer uses the rank/file board lights to display the current level.
It also displays a code on the LCD display that corresponds to the current
level.

For example, if you choose level B-2, the rank/file board lights indicate
square B2, and the display shows L-2E.

The number in the code that appears on the display shows the search depth
(the number of moves the computer will consider before making or
responding to a move), and the second letter in the code shows the search
variation (the number of move types the computer will consider before
making or responding to a move).

After you install batteries or press ACL to reset the computer, it resets
itself to level B2.  After that, the computer remains on the last selected
level.

Viewing the Current Level

To view the current level, press LEVEL once.  The computer beeps, the
rank/file board lights indicate the level, and the display shows the code
that corresponds to the level.

Changing the Level

To change the current level, press LEVEL until the level you want is
indicated by the rank/file board lights and its code appears on the
display.

To quickly move through the levels, press COLOR to skip over 8 levels at a
time.

When the computer displays the level you want, simply press NEW GAME (to
start a new game) or make your next move (to continue the current game).
You can change the level at any time during a game.

Choosing a Level

If you are a beginner, start out with the fun levels (G1 through G8),
handicap levels (H1 through H4), or lower fixed depth levels (F1 through
F4).  The computer purposely makes mistakes on the fun levels so you can
beat the computer and learn while doing so.  The handicap and lower fixed
depth levels restrict the computer's search depth, resulting in weaker
play.  For more information, see "Fun Levels (G1 through G8), "Handicap
Levels (H1 through H4), "or" Fixed Depth Levels (F1 through F7)."

If you are an intermediate or advanced player, try the standard levels.
These range from easy all the way up to difficult.  The higher fixed depth
levels are also challenging.  For more information, see "Standard Levels
(A1 through E7)," "Indefinite Response Time Level (E8)," "Fixed Depth
Levels (F1 through F7)," "Puzzle Level (F8)," or "Mate Search Levels (H5
through H8)."

Note:  When you set the level, keep in mind that when the computer has
       more time to think about its moves, it plays better.

Standard Levels (A1 through E7)

The 39 standard levels increase in difficulty from level A1 (L-1A) the
easiest) to level E7 (L-8d) (the most difficult).

Indefinite Response Time Level (E8)

At the indefinite response time level, the computer searches for a move
until it either finds a checkmate or has searched all possible moves (up
to 8 ply) and cannot find one (a ply is one move for either side).  Use
this level to have the computer analyze complicated positions for hours or
even days.

Note:  Press PLAY once to terminate the computer's search for a move and
       force it to make a move.

Fixed Depth Levels  (F1 through F7)

At these levels, the computer's search depth is limited by the level you
choose.  The number in the displayed code indicates the number of moves
the computer will look ahead.

For example, if you set the computer to fixed depth level F1 (L-d1), the
computer searches ahead only 1 move, so it will often overlook a checkmate
in 2 moves.  This gives beginners and average players a better chance to
win.

Puzzle Level (F8)

At this level, the computer will analyze the current game and display any
move it finds that will either checkmate the opponents king or capture an
opponent's piece worth more than 1 point.  The computer assigns point
values to the following pieces:

  Pawn    (1 point)

  Bishop  (3 points)

  Knight  (3 points)

  Rook    (5 points)

  Queen   (9 points)

If the computer finds a move that will allow it to either checkmate the
opponent's king or capture a piece worth more than 1 point, it displays
the move.  If it cannot, it sounds an error beep.  Then you must change
levels to return to normal play.

Fun Levels (G1 through G8)

The 8 fun levels allow beginners and average players to play (and win)
more easily than in other levels.  The computer makes common mistakes such
as leaving pieces unprotected, failing to capture unprotected pieces, and
capturing pieces while leaving the king unprotected.

Level G1 (L-F1 is the easiest, and the computer's playing strength
increases gradually up through level G8 (L-F8).

Handicap Levels are meant especially for beginners.  At these levels, the
computer moves almost instantaneously, not allowing itself to study a move
in any depth.

Level H1 (L-H1) is the easiest, and the computer's playing strength
increases gradually up through Level H4 (L-H4).

Mate Search Levels (H5 through H8), regardless of the opponents defense.
The computer will search for the shortest possible solution to checkmate
problems.  If no checkmate is possible or the computer cannot find a
checkmate, it sounds an error beep.  Then you must change levels to return
to normal play.

ENTERING MOVES

Playing chess against the computer is like playing with a human opponent - 
you make your move, and the computer responds with its move.  The only
difference is that you must physically move both your and the computer's
pieces.  To make a move, press down gently on the center of the FROM, then
the TO squares.  The FROM square is the current location of the place you
plan to move; the TO square is where you are moving the piece.

Note:  On the LCD display, an OUTLINED FIGURE - - indicates it is white's
       turn to move, while a DARK FIGURE  - - indicates that it is black's
       turn to move.

Note:  Once you press a piece (either yours or the computer's) down on a
       FROM square, you must complete the move by pressing a TO square
       before you can press the COLOR, DISPLAY MOVE, or EVALUATION keys.
       If you try to use any of these keys before you complete the move,
       the computer sounds an error beep.

Follow these steps to enter moves.

1.  When it is your turn to move, press down the piece you want to move on
    the FROM square.  The DISPLAY shows the piece you pressed and the FROM
    square, and the rank/file board lights show the FROM square.

2.  Press the piece gently down on the TO square where you want to move
    the piece.  A DARK FIGURE displays with a number.  The number changes
    while the computer plans its move.

Notes:  The computer might respond instantly, so you might not see the
        DARK FIGURE and a number.

        During the computer's turn, the number displayed next to the DARK
        FIGURE might count down to 0, then start over.  This is because
        the computer has changed its mind about its line of play and is
        searching down another line.

        If you do not wish to wait for the computer to calculate its move,
        press PLAY once to force the computer to make a move.

3.  When the computer is ready to move, the display shows the piece the
    computer wants to move and the TO square.  The rank/file board lights
    show the FROM square.

Note:  If the computer's move captures one of your pieces, the black
       piece's symbol and X appear on the display.

4.  Press the computer's piece down on the FROM square.  The display again
    shows the piece the computer wants to move and the TO square, and the
    rank/file board lights show the TO square.

5.  Press the computer's piece gently down on the TO square.  The display
    shows the OUTLINED FIGURE - -  to indicate it is your turn to move.

Here's an example of how to move pieces and communicate with the computer.
Try it now!

1.  Press the White pawn on square E2.  The display shows TRIANGLE E2 and
    the rank/file board lights flash at square E2.

2.  Move the pawn to square E4 and press it on the square.  The display
    might show the DARK FIGURE and a number.  The computer records your
    move and begins to think about its move.

3.  The computer might display a BLACK TRIANGLE and E5 for its TO square
    (you might get a different response), and the rank/file board lights
    show the current location of the piece the computer wants to move.

4.  Press the black pawn on its current location.  The computer displays a
    BLACK TRIANGLE and E5 for its TO square (you might get a different
    response), and the rank/file board lights show the location where the
    computer wants you to move the piece.

5.  Press the black pawn on the location where the computer wants you to
    move it.  The computer displays an OUTLINED FIGURE - - to indicate it
    is your turn to move.

For each move, remember the three basic steps:

    press, move, and press again.

CORRECTING ACCIDENTAL WRONG MOVES

If you press down on a piece and the FROM square information appears on
the display, but you decide not to make that move, press the piece down on
the FROM square again.  The computer displays an OUTLINED FIGURE - - and
you can enter another move.

When you complete a move by pressing the piece down on the TO square, the
computer accepts it and immediately considers its next move.  If you
change your mind after completing a move, wait for the computer to
indicate the move it wants to make.  Enter the computer's move, (see
"Entering Moves," then press TAKE BACK.  The computer shows you how to
take back its last move.  After you take back the computer's last move,
press TAKE BACK again.  The computer shows you how to take back your last
move.

ILLEGAL MOVES

The computer only allows moves that are in compliance within the rules of
chess.  Illegal moves are not accepted.  The computer notifies you of an
illegal move or error by beeping an error tone (if the sound is on).  The
FROM square information on the display and the rank/file board lights also
remain unchanged if you make an error.

These things cause the computer to indicate an illegal move:

Pressing on a piece of the wrong color (e.g., it is white's turn and you
press on a black piece).

Pressing on the wrong square when making the computer's move on the board
(e.g., the rank/file board lights show square C5 and you press square B5).

Pressing on an empty square without having first pressed a piece that can
move to that square.

Moving a piece that puts or leaves your own king in check or checkmate.

Attempting to castle by moving the rook before the king.

Note:  If you move your rook incorrectly when castling and you moved your
       king first, the DISPLAY shows OUTLINED FIGURE 00 (on a queen side
       castle), then the rank/file board lights show the correct square
       for the rook.  Press the rook on the square the computer indicates.

If it is your move and you have already moved the king, press the rook on
the FROM square.  The computer displays an OUTLINED FIGURE, indicating
that you complete the move.

If it is the computer's move, the display and the rank/file board lights
show the TO square.  Press the piece on the TO square.

(br/all-7/12/94)