Excalibur electronic 974 manual GO key, which will set the num- ber of players back to one

are beginner levels and take approximately 4, 8, 12 and 16 sec- onds per move, respectively. Level 5 is a fixed 1-ply (one-half move) search. Levels 6 through 15 take about 1 second per level number, so level 10 will average about 10 sec- onds per move. Levels 16 through 72 take about 2 seconds per level number. The amount of time taken will vary depending on the position, the stage of the game, and whether or not the FAST level option is on. (See “Level Options,” page 6.)

Level 73 is an infinite level. Electronic Chess will take as long to move as you want it to, or until it finds a mate position in its search. Level 73 is good for problem solv- ing (like the MATE problems avail- able under OPTIONS), or it can be used to play against. When you are tired of waiting, press the GO key while the computer is thinking, and the computer will stop thinking and play the best move it’s found so far.

If you wouldA tolikePlayto watch the computer finish a game for you automatically, press the 2nd key, then press the PLAYER key repeat- edly to change the number of play- ers to zero. Press CLEAR and then press the GO key twice and watch the game play itself. You may stop auto play at any time by pressing

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the GO key, which will set the num- ber of players back to one.

You mayReplayautomaticallyVariationreplay all the moves saved by Electronic Chess for undoing. If you would like to replay the stored moves, first undo all the moves by pressing the 2nd key, and then press the PLAYER key repeatedly to change the number of players to zero. Press CLEAR and then press the UNDO key. Now to replay the variation and return to your original position, press the 2nd key, then press the PLAYER key repeatedly to change the number of players to zero. Press CLEAR and then press the GO key and watch the moves. Electronic Chess will stop Auto Play when it arrives at the original position.

ElectronicBook OpeningChess makesTrainerit easy for you to learn the same openings that world chess champions play! At the beginning of a game, you may choose to learn one of 34 pop- ular book openings—ways to begin the game—used by chess masters. Press 2nd, then OPTIONS, to dis- play OPEn, and then press the -1or +1 keys to select the number of the opening you want to learn. (See right.) Then press the CLEAR key to return to normal play.

Now play a move. If your move is not the correct opening move, an error buzz will sound. To learn the correct move press HINT. When the

computer comes back with its move, you will briefly see the word OPEn on the screen if you have another opening move to make. If the word OPEn does not appear, you may continue normal play. You have completed the training for that opening line.

The names of the openings are:

1.Ruy Lopez, Exchange Variation

2.Ruy Lopez, Closed Defense

3.Ruy Lopez, Open Defense

4.Ruy Lopez Archangel Defense

5.Giuoco Piano

6.Scotch Game

7.Four Knights

8.Petroff Defense

9.Vienna Game

10.Sicilian, Classical Defense

11.Sicilian, Accelerated Dragon

12.Sicilian, Rossolimo Attack

13.Sicilian, Dragon Variation

14.Sicilian, Scheveningen Variation

15.Sicilian, Najdorf Variation

16.Sicilian, Moscow Variation

17.Caro-Kann Defense

18.Panov-Botvinnik Attack

19.French Defense, Winawer Variation

20.French Defense, Classical Defense

21.French Defense, McCutcheon Variation

22.French Defense, Tarrasch Variation

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23. Queen’s Gambit Accepted

24. Queen’s Gambit Declined

25. Queen’s Gambit, Semi-Slav

Defense

26. Queen’s Gambit, Tarrasch

Defense

27. Queen’s Gambit, Slav Defense

28. Nimzo-Indian Defense,

Rubinstein Var.

29. Nimzo-Indian Defense,

Classical Variation

30. Queen’s Indian Defense

31. Queen’s Indian

Defense, Petrosian

Variation

32. Bogo-Indian Defense

33. Gruenfeld Defense

34. King’s Indian Defense

The moves and explanations of these famous openings are given in many books on chess.

EnteringElectronicYourChessOwnalso allowsOpeningyou to set up any book opening you want—or even an opening you invent—to practice. Press 2nd then repeatedly press PLAYER until the display reads 2PLAYr. Press CLEAR, then make moves for both sides until the opening position you want to practice is reached. Now press 2nd then repeatedly press PLAYER until the display reads 1PLAYr. Press CLEAR and play against the computer in this posi-