| CYRUS II
CHESS PROGRAM FOR AMSTRAD INSTRUCTION MANUAL SOFT 06026 (TAPE) SOFT 07026 (DISC) (c) Copyright 1985 Intelligent Chess Software Ltd CONTENTS 1 INTRODUCTION 2 LOADING THE PROGRAM 3 STARTING A GAME 4 THE TWO CHESSBOARD DISPLAYS 5 SPECIAL MOVES 6 CORRECTING ERRORS 7 MESSAGE DISPLAY 8 RESULT OF THE GAME 9 INTERRUPTING THE COMPUTER 10. NEW GAME 11 LEVELS OF PLAYING STRENGTH 12 CHANGINGSIDES 13 PLAYING BOTH SIDES 14 DEMONSTRATION 15 RETRACTING AND REPLAYING MOVES 16 HINT 17 ANALYSIS 18 SETTING UP A POSITION 19 CHESS PROBLEMS 20 SAVING AND LOADING GAMES 21 PRINTER 22 SUMMARY OF COMMANDS APPENDIX: THE MAIN RULES OF CHESS A THE CHESSBOARD AND PIECES B THE MOVES C CHECK AND CHECKMATE D CASTLING E STALEMATE AND OTHER TYPES OF DRAW 1. INTRODUCTION Cyrus II is a chess program to interest players of all levels. Its abilities range from almost instantaneous play suitable for a beginner, through to tournament-style play for chess experts. It offers a wide range of operating features, enabling you (for example) to take moves back, replay a game that is over, or set up special positions for problem-solving. Cyrus II can also play against itself, allowing you to learn by study and example. Or it can stand aside, keeping a watchful eye on a game between two humans - ready, when asked, to analyse the situation and give advice. A novel feature of the program is its attractive "three-dimensional" chessboard display. A more conventional diagrammatic display is also provided as an alternative. It you like, start up the program and find out by experiment how to use it. No harm can come, whatever key you press, and Cyrus will do its best to understand your intentions We recommend, however, that you read this manual as far as Section 5 ("Special Moves") in order to get under way quickest. You can then return to the manual for reference whenever you need to. 2. LOADING THE PROGRAM The program comes in two versions - on cassette or on disc (a) Loading from cassette Follow the standard procedure for setting up the computer, as described in the Amstrad CPC 464 user manual. Connect up your printer if you want to use it with the program (see Section 211. Insert the Cyrus II cassette into the built-in cassette recorder, and make sure the tape is wound back to the beginning. Then type RUN"" -and press either of the blue ENTER keys The computer now Kompts you "Press PLAY then any key" When you have done is, the taDe automatically starts, and after a few seconds the message "Found CYRUS' should appear on the screen The process of loading will take about 3 minutes (b) Loading from disc: Connect up the computer disc drive and printer (if desired*, as described m the relevant operating documents. Switch on the power and type RUN " DISC <ENTER> When loading is complete, a chessboard appears, and the pieces are inserted ¯n their starting positions If you want the program to work with its sound signals the volume control on the nght-hand side of the computer should be turned up to an audible level. The volume can be readjusted at any time 3. STARTING A GAME Inside the square at the bottom left-hand corner of the board, you will see a flashing white arrow. This is the marker, which is usee for ndicating your moves to the computer. By means of the four "direction" keys (<-||->>, you can move the marker around the chessboard to position it wherever you want A Quick key-press moves the marker one square in the direct'on indicated If you hold the key down, the marker keeps on mov-ng i until it reaches the edge of the board, or the key is released* If you are playing White, make your first move like this:- (a) Place the marker on the square occupied by the piece you want to move (so that it points towards the base of this piece). (b) Press one of the ENTER keys The computer Deeps and the marker stops flashing (c) Press a "direction" key again; you will now see two markers One is flashing, and responds to your commands, the other one, pointing towards your piece, remains static (d) Move the flashing marker to the square where you want the piece to go (e) Press ENTER again ("beep"). Your move is now earned out. and Cyrus starts computing its reply When it is ready, it beeps" and moves its piece on the boara Make your next move in the same way as before Note that the two blue keys marked ENTER are identical in their effect Also, m place of either of these, you may use the COPY key which is located in between the arrow keys You can make the program move first - if you want to play Black - by pressing M In this case, before the game starts, you will probably want to invert the chessboard by pressing the I key. The strength and speed of the computer's play can be altered whenever you like; see Levels of Playing Strength on page 8. as well as "Message Display" (page 6) 4. THE TWO CHESSBOARD DISPLAYS If you press the ESC key. the "three-dimensional" image of the board and pieces is replaced by a two-dimensional diagrammatic display On the diagram, the marker takes the form of a flashing yellow square The operation of the program is just the same whichever display you are using, and the ESC key can be used to switch from one to the other at any time 5. SPECIAL MOVES A capture is made no differently from any other move - simply move your own piece to its destination square The same goes for a pawn capture en passant In order to castle, make the move of the king, and the rooks move is made for you automatically If you advance one of your pawns to the far end of the board, this pawn will repeatedly move back and forth until you tell the computer what piece you wa.it in its place Press Q. R. B or N according to whether you want a queen, rook, bishop or knight (Other keys have the same effect as Q When Cyrus promotes one of its own pawns, it always chooses a queen.) If you aren't sure of all the rules which apply to these special moves, turn to the Appendix (pages 24 and 27-29). 6. CORRECTING ERRORS If there is only one marker visible, and it is not on a square occupied by a piece that can move - then a press on an ENTER key will simply produce a dull buzz, the error signal. The same thing happens if you press ENTER when the static marker is pointing to one of your pieces and the flashing marker is on a square where this piece cannot legally go In either case, simply re-position the flashing marker and continue entering your move. If the static marker is pointing to a piece which you decide not to move after all, bring the flashing marker back to this same square - so that it disappears, leaving only the static marker visible The re-press ENTER The marker begins 'lashing, and you can start again to move another piece 7. MESSAGE DISPLAY On the two-dimensional" display the word CYRUS or PLAYER, m black or white at the top or bottom, snows whether the computer or the user is playing from this end of the board and witch which colour On the three-dimensional" screen, the contestant playing trom the bottom end is recorded on the left-hand side oe*o* the chessboard, while blue lettering shows who is playing Black. A clock reading is also displayed for each opponent for example 01 : 17:36 - meaning that the total thinking time so far used by this s¯de is one hour seventeen minutes and thirty-six seconds By seeing which ciock' is going, you can tell which side is to move next If you press the SPACE BAR. the screen changes to a different type of display. In place of the chessboard, you will see a record of the last few moves made and a list of the commanas currently at your disposal. Here is how moves are recorded. Each file (or vertical column of squaress) is given a letter viewed from the "White" side the letters range from "a" (on the exteme left) to "h" Each rank tor horizontal row) is given a number, running from i tat White s end) to 8 Each square is designated by the letter of its file ana the number of its rank. (So at the start of the game, the white king is on el. the black queen is on d8, etc.) A move by a pawn is recorded by simply naming the pawn's old and new squares When any other piece moves, its initial letter (or N m the case of a kmghti is inserted before the departure square Example- 1 e2 - e4 d7 - d5 2 e4 x d5 Ng8 - f6 3 Bf1 - b5 + White has started by moving his pawn from e2 to e4 oe the pawn in front of his king has gone 2 squares forward) Black has replied with a double advance of the pawn in front of his queen - from 67 to d5. Then the White pawn has captured the black one (a capture is indicated by "x"). and Black has brought out his knight from g8 to f6 On his third move. White has played his bishop' from fl to b5. the "+" sign shows that this move gives check. White's moves are always listed on the left. Black's on the nght. Castling (on the king's side or queen's side respectively! is denoted by "O-O" or "O-O-O" Below the game-record, you will see either the word THINKING (if Cyrus is computing the next move) or else YOUR MOVE. Lower down the screen, there is a list of the commands that are currently available, eg: B-Back - reminding you that by pressing the B key you can retract a move as described on page 10 The full list of commands iwhich is reproduced on page 16) should be clear to you once you have read the remaining sections of this manual To return from the message screen to the chessboard screen. press the SPACE BAR again. 8. RESULT OF THE GAME The message screen displays CHECKMATE or STALEMATE if such a situation has come about. If Cyrus recognizes that the same position (with the same side to move) has arisen three times, it announces a DRAW. A draw is also announced if, over the space of 50 consecutive moves (played by one side and answered by the opponent), no piece has been captured and no pawn moved. To signify the end of the game, one of the kings (that of the player whose opponent made the last move) repeatedly flashes" on the chessboard display. If you want to check upon the rules which determine a drawn result, turn to the Appendix, page 30. 9. INTERRUPTING THE COMPUTER If you press the M key while Cyrus is computing its move it will cut short its calculations and play the move assessed as best according to its analysis so far Notice that most of the special operating features described below teg selection of the 'level'' retraction of moves, etc) will not work when it is the program's turn to move By inducing a move, you enable any of the features to be used 10. NEWGAME You can begin a new game at any time, by pressing the G key The screen then shows:- New Game(y/n) To confirm your command, press Y The starting position reappears, and both "clocks" are set back to zero. Note that until you actually enter a move or start Cyrus computing, the previous game still remains in the computer's memory. You can return to any position in that game by using the F key- see page 10. If you have pressed G by accident, a key-press other than *Y" allows play to be resumed 11. LEVELS OF PLAYING STRENGTH There are various levels of skill on which Cyrus II may be instructed to play. Obviously, the program plays more strongly the more thinking time it has for its moves. The following table shows the approximate average time it takes for a move on Levels 1 -9. Level Time 1 2 seconds 2 6 seconds 3 15 seconds 4 30 seconds 5 45 seconds 6 1 minute 7 2 minutes 8 3 minutes 9 2 minutes 30 seconds There are also three further levels, called "adaptable", "infinite" and "problem" When playing on the adaptable level, Cyrus aims to play at roughly the same rate as its opponent; it measures your thinking time over a series of moves, then speeds up or slows down as necessary When computing a move on the infinite level. Cyrus will normally carry on thinking unti' you tell it to move by pressing M. If you don't do this, the computer will not actually play a move unless: (a) it has a book move available see beiowi or (b) it finds a forced mate or completes as oeep an analysis of the position as is within its capacity: or (c) there is only one legal move it can make On the problem level, the program searches tor a way to force checkmate in 5 moves or less, for more details see the section on "Chess Problems' (page Mi When you first set up the program. Cyrus is ready to play on Level 1. The current level can always be seen on the message display. You may change the level any time when it is your turn to move, by pressing the L key A single key-press takes you one level higher If you hold the key down, you will see the level constantly changing - after going up to Level 9. the screen shows ADAP INF PROB. and then Level 1. Level 2 ... and so on. When the level that you want is displayed, simply carry on playing. The program remains on the same level (even after a new game starts), until you change it again, you may do so as often as you like. NB. (a) Like a human player, Cyrus normally takes more time in a complicated position than in a relatively simple one So the time it takes for an individual move is sometimes much more than the average for the level. (b) Cyrus has knowledge of a large number of standard chess openings, so the first few moves of a game (on any level) are likely to be played fast. In a position where the program has two or more "book" moves available, it chooses between them largely at random. The total number of moves in the "openings book" is nearly 1900 <c) Cyrus normally continues analysing the position even when it is your turn to move; so if it anticipates your next move correctly, it may reply instantaneously, irrespective of the level 12. CHANGING SIDES If you press the M key when it is your turn to move. Cyrus will start computing a move for the side that you have been playing, and will expect you to take over the other side You can change sides like this as often as you like. When you do so. you will still be playing "up the screen". To invert the board, press the I key. 13. PLAYING BOTH SIDES It's possible for you to play a series of moves for both White and Black. For example, you may want to enter the moves of an opening variation which interests you, to see how Cyrus handles the resulting position. To do this, press S followed by M (you will then see the word PLAYER at both sides of the chessboard screen). You can now enter moves for both sides in turn When you want Cyrus to carry on playing, re-press the Mkey This "multi-move" feature enables two human opponents to play a game against each other with the screen display as their chessboard 14. DEMONSTRATION If you press the D key, both sides will be taken over by the program, as a demonstration game. (Then CYRUS will be displayed at both side ends of the screen.) After finishing a game, the program will pause for a few seconds and then begin a new one. To halt the demonstration, press M Then, after the next move is made, you may continue the game against the computer. 15. RETRACTING AND REPLAYING MOVES If you've played a move but then have second thoughts about it you can easily take it back. Wait for Cyrus to reply, or make t do so at once by pressing M. Then press B. and the program's move is retracted. A second press on this key retracts your own last move, and you may make another one in its place A move can be taken back even when the program is displaying checkmate or a draw. By pressing the B key repeatedly or holding it down, you can take back a whole series of moves by both sides (going right back to the start of the game if you want). Notice that if you take back one more move for White than for Black (or vice versa), you swap sides with the computer. The F key ("forward") has the opposite effect to the B key. it replays the move or moves that you have taken back. As one example of its use. suppose that during a game you want to have another look at a position which arose 10 moves earlier Take back the 10 moves with the B key, then, after you have finished examining this position, hold down the F key until you arrive again at the position where you interrupted the game. Play can now be resumed You can retract and replay the same sequence of moves as many times as you like. You may also carry on playing from any position within the sequence. This means you can find out what would have happened if you had played differently at a particular stage of the game. Note, however that when - in any position - you enter a new move or press M (or D). you are erasing from the computer's memory the moves that had previously been played from this position onwards Those moves can no longer be replayed with the F key To review the entire game you can press the G key (so that the starting position reappears), then repeatedly press F. This is not. however, possible if the game began from a position which you "set up" (see Section 18). 16. HINT If you want Cyrus to suggest a move for you. press H. One of your pieces makes a move on the board, and then goes back again. It is for you to decide whether to act on this hint; it is not necessarily the best move available (especially on the program's lower levels), though Cyrus will not deliberately mislead you If you press H when Cyrus is computing the next move, one of the program's pieces is moved back and forth in the same way This shows you what move was rated as best at the outset of the analysis 17. ANALYSIS If you would like some further insight into the program's train of thought, press the A key. The word ANALYSIS appears on the message screen. Now press the M key If Cyrus has just started computing its move, the display will now remain unchanged tor a few moments, but after that a series of moves will be recorded just above the list of commands. The first move in this series is the one that Cyrus is thinking of playing next - the best move according to its analysis so far. The following move is your expected reply, then comes the computer's intended answer to that and so on. For this feature a simplified form of notation is used - each move is indicated merely by giving the old and new squares ot the piece. The analysis displa can be cancelled by repressing the A key Please note that this function is not available until each player has made at least 8 moves 18. SETTING UP A POSITION Now and again you may want to see Cyrus solve a chess problem; or you may wish to set up a position from a game that has been published, to see how the program handles it. in or ar to rearrange the position on the chessboard, first press the S key. The wording SET UP appears on the chessboard screen - in "set up position" mode, some of the keys have different uses from their normal ones. As long as SET UP is displayed, you can do any of the following things- (a) You can clear the entire chessboard by holding down a SHIFT key and pressing CLR. Usually you will want to do this before anything else - but not if the position that you intend to set up diners only slightly from the position currently displayed. (b) To clear an individual square, position the marker on that square and press CLR (without SHIFT) (c) To insert a piece on the board, bring the marker onto the desired square and press the appropriate key: K (king), O (queen), R (rook), B (bishop), N (knight) or P (pawn) The way to select the colour of the piece will be explained presently. (d) Both of the clock times can be set back to zero by pressing Z (Notice that as long as the program is in "set up position" mode, the clocks are stopped.) On the screen you will see the word WHITE or BLACK. This shows which colour a new piece will be, if you now place one on the board To change over from one colour to the other, press X The word WHITE or BLACK also indicates which side will move next if play is commenced at this moment. So once the position is ready, you may need to press X to display the correct colour Finally press the S key. to take the program out of "set up position" mode again. The normal list of commands will now be shown on the message screen, and play may proceed Here's an example of how a position is set up. We'll suppose that the position you want is the following, and that White is to move Press S "SET UP" appears on the chessboard screen. Hold down SHIFT. The board is cleared and press CLR. If the word BLACK is displayed, press X (message WHITE). You can now place white pieces on the board Bring the marker onto the square where you want the white king (b2). Press K. A white king appears Bring the marker onto the square 'or the white pawn (b3). Press P. A white pawn appears Bring the marker onto the square for the white queen (c4). Press Q A white queen appears Press X. The word BLACK appears You can now enter black pieces Bring the marker onto the square for the black king (f6). Press K. A black king appears Bring the marker onto the square for the black queen (g5). Press Q A black queen appears Press the X key again (message WHITE) Cyrus now knows that when play continues from this position, it will be White to move next. Finally, press S. The wording SET UP disappears, and YOUR MOVE is shown on the message screen Play can now begin. Adjust the "level", if you want; then press M. to start Cyrus computing. (Or else, if you are playing White yourself, make a move in the usual way) In connection with setting up positions, there are a few more points to be noted:- (a) Illegal positions:- If you've set up a position in which (say) there are no kings, or one side has two queens as well as eight pawns, or Black's king is in check when White is to move- then Cyrus recognizes this position as illegal With such a position on the board, it is impossible to take the program out of "set up position" mode and continue playing; when you press S. the computer will merely give the 'error buzz" and display ILLEGAL SET UP. Correct the position as necessary. (b) Castling:- If a king or rook has been placed on the board in the way we have just described, there can be no castling with that piece. A position in which (say) White has the right to castle king's side may be set up as follows. First press G and Y (the starting position appears), then enter "set up position" mode by pressing S The white king and king's rook should now be left alone, while unwanted pieces are removed individually with the CLR key. (c) En passant captures:- After a position has been set up. the next move cannot be a pawn capture en passant To create a position where such a capture is legal, set up the immediately preceding position and then make the move which permits the capture (d) Game record:- When play proceeds after you have set a position up. the numbering of subsequent moves always begins from 10. The computer's memory of any game you had previously been playing is now erased This does not. however, mean that the foregoing moves are erased from memory if you press S by accident in the middle of a game. As long as you re-press the same key without actually having made any alterations to the position, play may continue as before. The numbering of the moves remains unchanged, and if you like they can be "taken back" or "replayed" in the normal way. 19. CHESS PROBLEMS Most chess problems carry some such wording as "White to play and mate in three moves" - meaning that you have to find a move which enables White to give checkmate on his third move at the latest, no matter how Black tries to defend himself Cyrus II can solve problems for mate in anything up to 5 moves Set up the position as described in the preceding section Make sure Cyrus knows which side moves next Select "problem" level with the L key. On leaving "set up position" mode, press M to start Cyrus computing. Cyrus now begins by looking for a move that gives checkmate immediately If it discoves that this is not possible, it displays NO MATE IN 1 on the message screen, and starts searching for a way to force mate in two moves .. and so on. If the program finds (say) a forced mate in 3 moves, it momentarily displays MATE IN 3. and makes the appropriate move on the chessboard. You may now make a move for the defending side. Then (after re-computing if necessary), Cyrus will play the next move of the solution. After that, you can, if you like, take back the last pair of moves, and play a different move for the defence, to see how the program answers it. If Cyrus discovers, by performing an exhaustive analysis of the position, that it is impossible to force checkmate within 5 moves, it displays NO MATE IN 5. and simply makes the move it considers best NB. (a) if there is a "book move available. Cyrus will move immediately, without performing any analysis. (b) Cyrus cannot solve problems that require "under-promoting" a pawn to rook, bishop or knight. 20. SAVING AND LOADING GAMES The record of a game may be saved on cassette or disc, and at a later date re-loaded into the computer for resumption of play, or for replay and analysis, etc If you have loaded Cyrus from tape, you will use a cassette for saving and loading games. Insert a suitable one into the built-in cassette recorder, and press the C key. You then have the following options (the text on the message screen will guide you in your operations):- (a) To save a record of the game you have been playing, press S The computer then prompts you to give the game a name (for instance FIRSTGAME); this must comply with the format for filenames as explained in the computer's operating manual. It cannot include blank spaces. Type the name and press ENTER. You are now prompted to start the tape and press any of the computer's keys. This will begin the saving process; once it is finished, the program reverts to normal playing conditions. (b) To load a game from cassette, make sure the tape is wound back far enough, and press L Type the name under which the game was recorded, press ENTER and the PLAY button, then press any key on the keyboard. When loading is complete, the final position of the game record can be viewed on the chessboard screen, and you may make use of any of the program's functions. (c) To allow play to be resumed (if, say, you pressed the C key by mistake), press any key other than S or L If you are using the disc version of Cyrus, games can be saved and loaded from disc using exactly the same set of commands (C followed by S or L). 21. PRINTER If you have a printer connected, pressing the P key allows you to give instructions for its operation This key-press automatically switches to the message screen, which lists a special set of commands. The options are as follows:- (a) For a print-out of the complete game-record in memory, press G (b) Pressing B causes the current position on the board to be printed. (c) Press D for a continuous listing of moves. This means that when play continues, each move will be printed out as soon as it is made The listing can subsequently be halted by repeating the same command. (d) The facility of inserting a "line feed" together with each carriage return" can be switched offor on by pessing L An asterisk on the screen indicates that the facility is "on". (e) Any other key-press allows play to be resumed 22. SUMMARY OF COMMANDS A Display analysis (predicted continuation). Repeat to cancel. B Take back last move: promote pawn to bishop C Casette operation. : L Load game record : S Save game record. : Other keys: return to normal playing mode.) D Demonstration (program plays both sides) F Step forward. ie replay move taken back. G New game. : Y Yes. : Other keys: no. H If user to move, give hint: if program to move, show move currently assessed as best I Invert chessboard. L Change level. M Take over the side which is to move; if already on this side, move immediately. N Promote pawn to knight P Printer operation. : B Print board position : C Continuous listing (each move printed when played). Repeat to cancel. : G Print game record. : L Carriage return + line feed (off/on). : (Other keys: return to normal playing mode.) Q Promote pawn to queen. R Promote pawn to rook. S Selects "Set up position" mode : B Bishop. : K King. : M Multi-move mode (user plays both sides). : N Knight. : P Pawn. : O Queen : R Rook. : S Return to normal playing mode. : X Change colour of pieces to be entered and side to move : Z Set both clocks to zero : CLR Clear square. : SHIFT + CLR CIear entire chessboard ENTER During move entry, selects square of departure (COPY) or destination. ESC Switch between chessboard screens. <- | | -> Move cursor. SPACE BAR Switch between chessboard and message screen. ------------------------------------------------------------------------------ Retyped in 2011 by hERMOL Visit my website at http://CPCRULEZ.fr ------------------------------------------------------------------------------ |