Processor Technology 8080 CHESS User`s Manual
Contents
1. SECTION PAGE 5 CHESS PROBLEMS AND SAVING GAMES ccce nn 523 5 SAVING GAMES zv4G XR a eR WURDE EE E E Ee does 91 5 2 SETTING UP CHESS PROBLEMS s siid 9m my ew ee ders 5 2 Eu HAND TU CAPP ING ai EAEE Ere uper E RENS E ex 5 2 6 GAME DEPTH CONTROL AND DISPLAY cce ees 6 1 6 1 SETTING THE STRENGTH OF THE COMPUTER S GAME 6 1 631 Instructions for Setting the Depth Control 6 1 6 2 HOW THE PROGRAM FINDS ITS MOVE 6 2 6 2 1 Setting the Depth of the Tree Search 6 4 6 3 SEARCH DISPLAY Ge dt ada rs a a qnem a 6 4 6 3 1 A Penny for Your Thoughts Computer 6 4 6 3 2 How Many Nodes Did You Consider That Move 6 4 7 CHESS ROBOTS PLAY EACH OTHER ft sve Sites ol ti a ia E shea Se d APPENDICES 1 CHESS PRIMER 2 BIBLIOGRAPHY 3 ABOUT CASSETTE RECORDERS AND CASSETTE FILES 4 MOVE AND COMMAND SUMMARY REFERENCE FIGURES S 1 The Initial Display photo mala li is Sk S 2 4 1 Display of a Game in Progress photo 4 2 6 l The hook ahead TESE os o etna a ale Sas 9E 6 3 iv 8080 CHESS SECTION 1 INTRODUCTION This manual assumes that the player already knows the international chess regulations and terminology If you do not but wish to enjoy playing 8080 Chess you can find the basics and rules of the game in a handy Chess Primer in the Appendix of this manual Or have someone who plays teach you the basics before r2. Dis GIUOCO PIANO Ls P K4 P K4 235 Kt KB3 Kt QB 35 B B4 B B4 ay P B3 or P Q3 6 THE RUY LOPEZ ES P K4 P K4 2 Kt KB3 Kt QB 3 B KES Ia IHE FRENCH DEFENSE Ti P K4 P K3 2 P Q4 P Q4 3 Kt QB3 Kt KB 4 Be Sy KES P x P D Bx Kt P xB 8 QUEEN S GAMBIT l P Q4 P Q4 2 Kt KB3 P K3 Be P B4 Px P 4 Kt B3 Kt KB De B Kt5 B K2 6 P K4 P KR3 9 QUEEN S GAMBIT DECLINED Ta P Q4 P Q4 wae Kt KB3 P K3 35 P K3 P QB4 4 P B4 Kt OB Ds Kt B3 Kt B3 6 OP x P BxP ie P QR3 P QR3 8 P QKt4 B Q3 9 B Kt2 Castles ILLUSTRATIVE GAME AS AN illustrative game we present the fol was played by Morphy against the Duke Karl 3 3 3 3 3 in the Royal box at the Paris opera house Al 15 lowing famous masterpiece which of Brunswick and Count Isouard 8080 CHESS WHITE BLACK 1 P K4 1 P K4 TAR Kt KB3 ZAR p c ga 3 P Q4 Se IBS ORES 4 Px P 4 Bx Kt 5 Q x B Be TEA 6 B QB4 6 Kt KB3 Teo ORE d QQ KA2 B KE B3 BIB B3 Ou B 2oKKES 9 P Kt4 10 Kt x P 10 P x Kt 11 B x KtP ch 11 QKt Q2 T2 uU co I2 R Q 13 R x Kt 13 RAAR 14 R Q1 14 Q K3 LSe BX RCH UB KE X B 16 Q Kt8 ch 16 Kt x Q 17 R Q8 mate PROBLEMS THERE IS one branch of the art of chess that while not as popular as the cro
3. 4 4 CAPTURING Moves which capture ar ntered displayed and recorded exactly the same as regular moves as described above as if the square occupied by the man being captured were unoccupied 4 3 8080 CHESS 4 4 1 En Passant Capturing en passant is accomplished by entering the command PXNXN RETURN Where P The code for en passant XN The first XN The from square of the capturing pawn XN The second XN The to square of the capturing pawn EXAMPLE PD5C6 Player s pawn moves D5C6 capturing en passant 4 5 CHECKING A KING To check the computer s king simply enter the move as usual The program will notice if the move results in a check If the computer s move results in a check the letters CH will be printed alongside the move when it is recorded 4 6 CASTLING To castle left nter the command CL RETURN To castle right enter the command SER RETURN CAUTION The player is not given a trial move for castling the move will be executed upon the first RETURN The player s or the computer s ability to castle may be disabled and then re enabled The program begins the game with castling enabled for both player and computer The computer s castling may be disabled by the command RCO Where R Rook The computer s castling may be r nabled by the command RCl The player s castling may be disabled by the
4. IHE QUEEN The QUEEN moves and captures on the rank the file and the diagonal in any direction and over any distance over unoccupied squares In the following diagram 3 the spaces marked with a cross indicate the squares to which the Queen may move YY Uj aS Eat 1 Le ZZ 2 LL UY Y YUL dd We WE The Queen is the most powerful of the pieces possessing the combined powers of the Rook and Bishop While the mobility of the Queen makes it a very useful and powerful piece at any stage of the game still the player should guard against allowing it to be drawn out unnecessarily into positions from which it cannot be readily retracted Al 3 8080 CHESS The player should also always guard against allowing his Queen caught between his own King and an inferior at piece in such manner that his Queen may not move and escape cap pinned that is IHE ROOK The ROOK moves and captures in the rank and file only Squares In the following diagram 4 indicate the squares to which the Rook may move a VELLE B I 4 7 A Bic ERES HE Wy ty No 4 The Rook is next to the Queen in power and due hemmed in by its own pieces is seldom brought in Since the Rook in conjunction with the King to move stages of the game to be tacking cure over unoccupied the spaces marked with a cross to its original well not part in the joint move known
5. N returns control to SOLOS CUTER 4 5 8080 CHESS SECTION 5 CHESS PROBLEMS AND SAVING GAMES Sul SAVING GAMES The simplest way to save a game that you wish to continue at a later time ISi 1 Transpose the last position onto a regular chess board or transcribe a diagram of the position onto a piece of paper 2 When you are ready to resume the game load the game cassette and chose white or black If you chose black wait for the computer to move You can execute commands only when it is your move 3 Use the board positioning command as follows InXXXXXXXX RETURN Where I Code for positioning pieces on rank n of the chess board n The number of the rank to be populated 1 through 8 XXXXXXXX Desired occupants of the 8 squares in rank n given by Space Bar Vacant square P Pawn N Knight B Bishop R Rook Q Queen These upper case letters place the computer s chesspersons to place the player s chesspersons press the CTRL key simultaneously with the letter key 4 Repeat the positioning command for each rank Sel 8080 CHESS EXAMPLE To position the ranks given in Appendix 1 Chess Primer diagram No 9 Where the computer is black the hyphens are Space bars the periods are RETURNS s and the characters with bars over them are white B B g P PPR 6 NK a PSs e RS iG oi KNP
6. reading the manual any further That way you can see and demonstrate what the manual is referring to 1 2 3 4 Set up the cassette recorder and the video monitor as in the Sol Systems Manual Operating Instructions Monitor and Cassette Recorder Connections Rewind the cassette to the beginning Initialize the SOLOS or CUTER program to the command mode on the Sol by pressing MODE SELECT When the system displays the prompt character type XEQ and press RETURN This will load and execute the program if it is the next program on the cassette 5 If 8080 Chess is not the next program on the cassette type XEQ CHESS and press RETURN This will search ahead on the tape for the program load and excute it While loading the program the tape should be moving for about 2 1 2 minutes If the program is loaded into memory correctly the computer will stop the tape and display the initial frame with the chessboard as described in Section 3 The Display Refer to Fig 3 1 The Initial Display 2 1 8080 CHESS SECTION 3 IHE DISPLAY Sal THE BATTLEFIELD Refer to Fig 3 1 The Initial Display The chessboard is displayed on the video monitor as soon as the game is called up The player s side is always at the bottom of the vertical screen Each square is identified by means of a simple alphanumeric road map coordinate sys
7. 2 P R l NQ BR 5 Enter the castling status 6 Enter the desired depth if different from the default level Refer to Section 6 Game Depth Control and Display 7 Then all the ranks are set and if it was your move when the saved game was adjourned make your move now If it was the computer s move skip your move using the command YOU 52 SETTING UP CHESS PROBLEMS Set up the problem as if it were a saved game as in Section 5 1 above giving the mating side to the computer ES HANDICAPPING Use the positioning command to add or s on either your side or the c satisfactorily with the skil 9 LLY EXAMPLE omputer s l level of See how long it takes yo of queens instead of pawns Or you might disable the computer s casi NOTE to a smaller value to accomodate beginners tling ubstitute chesspersons as desired until you feel you are matched the program u to beat the program with a rank The depth to which the computer analyzes its moves Can be set Refer to Section 6 8080 CHESS SECTION 6 GAME DEPTH CONTROL AND DISPLAY 6 1 SETTING THE STRENGTH OF THE COMPUTER S GAME The strength of the computer s move is determined by the depth control The program automatically plays at a depth control setting of 32 pronounced three two The value of the first digit is the number of half moves ahead that the program will analyse its potential move
8. s moved and always m A Hs A Y however reason tha THE PAWN The PAWN moves forward only Each Pawn for its first move has the privilege of tion of the player square at a time moving two squares at the opi that does not capture as it moves diagonal squares adjoining it the eighth rank must be exchanged for a Queen series without regard to the number of such pieces Square on Knight of already on A Pawn which has been moved two squares on ii captured on the following move by a Pawn that it had moved only one square is called th sam the board En Passant with a cross indicate the squares to which in front precisely as In the following diagram No 6 and excepting for its first move could though it the Pawn A1 5 and throughout the game mov such movements constil t the Knight moves to the farthest The difference The Pawn is It captures on either of Each Pawn that is moved to a ts first The two Bishops are originally over t combining the uare like a not adjoin tuting one t corner oves to a square of In the following to which one sq are must however is two Bishops and a King constitute a mating force only one the only man the two Rook Bishop or move is liable to be have captured it if had so moved This 7 the spaces marked m
9. 8080 CHESS The next interested in programs order to play depth control are in NOTE subsection the game 6 1 the theory of operation of computer chess It is not necessary to read this subsection in the previous subsection is provided for those wh Instructions for setting 65 14 Setting the Strength of the Computer s Game 62 Much like a human considering its available moves subsequent moves possibl diagram of the rel HOW THE PROGRAM F N DS chess master ationships of search search lower level The positions in the tree can b the moves as lines branching from the positions tree or look ahead tree tree actually has only one root and grows downwards being much broader than the higher the program arrives at its m the res le for each resulting position the positions of a chess gam IS MOVE ulting positions an and s Refer to Fig 6 1 Look ah like a pyram cal represented as circles O abe the ove by d the oon A e is called a ead Tree A with each id led nodes and At the sta computer s move For the at the top of the tree it is the example in Fig 6 1 only thr starting position The starting position could be in game certain criteria i In the example its resultant position and stores it in i node with a lower from move 2 du
10. ay translating the letters representing the persons color of an occupied square you can set up an and transpose the moves from the computer display your moves on the real board This is also an aid in 3 4 RECORDING THE GAME The program records the moves in scrolling columns but unlike international notation 1 There is no nota tion of which chessperson moved 2 There is no nota 3 A check is noted screen tion that a move was a capture for computer moves but not for player s moves If you want a permanent copy of a game it would be best to transcribe the moves in standard notation before they are scrolled off the top of the a3 8080 CHESS SECTION 4 IHE MOVES 4 1 DO YOU WANT BLACK OR WHITE Refer to Fig 4 1 Display of a Game in Progress The program asks this question at the bottom of the screen If you wish to play white type W and press RETURN ablish two column headings for the PLAYER and COMPUTER move 01 The program will es and number the first A Cr The chesspersons are already set up for the player using white persons If you wish to play black type B and press RETURN The displays of the colors of the two sides and the position of the players side will remain the same but the program will reposition the queens to squares of their own color The computer then immediately makes the first mo
11. for example after the last file of interest name you will know not to search beyond it for files you are One way to avoid having to search for files is to record only cassette cassettes at the beginning of the tape A3 1 if you can afford the seeking one file per extra 8080 CHESS 10 tape at the ends beginning Tib Do not record on gets Record a file more than once redundancy can protect you from bad tape accidental erasure 12 Most cassett recorders hav the first or last the most physical trying to read the first file on a tape pre recorded program may have recorded before it leaves memory a featur minute of tape on a side The abuse Do not be impatient when You or the manufacturer of a a lot of empty tape at the This equipment malfunction and cassette from accidental erasure the exposed each end of tape not allow you to will remove this 13 Use cassette fxrst note th on all later r e reading cassettes ferenc the cassette of the cassette is are wri press protection the tape counter to keep Always rewind the casse putting a casset of the counter that allows you to protect a On the edge of the cassette opposite two small cavities covered by plas If one of the tabs is broken te protected the record button tic tabs one at out then o
12. represented at the limi th is called the terminal p ting depth are called termi erage ly the nal nodes A complex of nodes propogating from the same ply 1 parent node is called a branch node in each ply is call higher than the terminal ply string If a string ends in no 6 2 A chain of nodes connected together within a branch with only one led a string then that node is the terminal node for the de at a ply 8080 CHESS The program grows the tree one branch at a time to the depth assigned to it and evaluates the terminal nodes found on the branch giving a score to each terminal node as is shown in Fig 6 1 The score is lower proportionate to the advantage it gives the player and higher proportionate to the advantage it gives the computer The program gives the player the benefit of the doubt by assuming the opponent will find and take his or her best move Therefore the program takes the score of the terminal node having the lowest score and assigns it to the parent node connected to it on the next higher ply Looking horizontally on the new ply level it takes the minimum score of all the terminal nodes on that branch and assigns it to the parent node on the next higher ply It continues backing up the tree from node to parent node until the node at the first ply has the minimum score found in sea
13. the program starting position could be said to have anal and also gives Some of the moves it may reject out When it has considered all the moves available the level of positions lyzed the look ahead tree to a depth node 1 n the program ts memory score moves ar the program If the position is favorabl i if the position is unfavorable The program it a relative score shown available f rting position sake of rom the me or end the the opening the middle ga calculates a possible mov Scores the node with a h then evaluates the nod e 1 and and e according to igher score it scores the It does th resulting same to node of hand on principle is called ply 1 S stored in from the the program of one ce human life play chess to a fixed yer Upon three one ply Actually this is only a preliminary survey on the part of the program On the average there are about 30 moves available at each position in a game Each of these 30 moves has 30 replies and so on Sin is very brief and most of us have other things to do besides the program must be set to search the tree of possible moves depth 8080 Chess has a depth control accessible to the pla initialization it comes up with a preset default value of 31 which provides a good game to a player who is better than av Ih e ply level at the limiting dept positions
14. SECTI ON CONTENTS TNERODUEBTON sed Pronet A ee Bees ue EXE ELOADING THE CASSETTE eR DP VERS SUEDE TOR cen XR EUR Deer Rr THE DISPLAY ges qued Sy tar ae ves epee Um E UE Recs mde NOUS AM TU AM EAE ERES Sud EHE BATBEDBERLTEDNDiz6 a shen ted ae dd ove bee 3 Te sd Display of the Checkerboard Pattern 32 THE CONTENDERS leo Sa RUNS US UR UU EUR mS Soul The Complexion of the Chesspersons Ses AUXIDIARY DISPEBEAY32zciuc mee A A ie ede 3 7 RECORDING THE GAME sema RR m m ere ea as DEB MOVES de ets do de e eno edo dei e de 4L DO YOU WANT WHITE OR BDLAGCK 4 ow Rem Sle es 4 2 MOVES AND COMMANDS mmu onum RU GS Sle a 4 3 MOVING TO UNOCCUPIED SQUARES ee 4 3 1 Your MOVE rur dues ee els Eu ue 4 3 22 Computerh sMOVG seu 4 EA A SY es do CAPTURING ira gh Gaeta Ex RUND CDS CON gt Rte 4 4 1 EN Pas Sant quie emi vere ae enn Ia it Faz 45 CHECKING A KINGS daa a ERREUR EAE YI PRAES fr 60 CAS TILING oo ZG tee e y exe e eer iR US RR UR RC Se dare eae 4p TEBEGADL MOVESIS saterevd tery Socata hex ee ex eee ead AAs 4 9 PROMOTING PAWNS oode ees ue ewe dex aia 4 9 PASSING YOUR TURN TO MOVES 9 wmm RC 4 10 CONCEDING AND REMATCHES cce Xl 8080 CHESS CONTENTS Continued
15. and his capture is not permissible according to the laws of Chess One of three things must then be done 1 The King must move out of check 2 The hostile man that checks must be taken 3 A piece or Pawn must be interposed between the King and the attacking hostile piece If none of these things can be done the game is lost the King being checkmated In diagram 9 if black were first to move 1 QxP at Q4 would attack the white King thus administering check In this instance white could not move his King to a square that is not guarded by the black men or already occupied by one of his own men nor could the black Queen that gives the check be captured but white can prevent the immediate checkmate by playing either his Rook or Knight to K4 between the checking Queen and his own King yy UY 7 Z Y Yen UK YA Ze tie SES ie iy WME Up 4 gi s YU YY E 77 Z PERPETUAL CHECK occurs when the attacked King cannot escape from one check without rendering himself liable to another as in diagram 9 white with the move can if he so wished bring about perpetual check by Kt KB5 Ch and black is forced to play KR4 white plays Kt KKt 3 and black is forced to play KR3 white continuing Kt KB5 Ch Black cannot prevent this perpetual check of the Knight at KB5 and KKts 3 STALEMATE is brought about when the King although not at the moment in check is so s
16. as castling it is until the player is sure he does not When through the exchange of Pawns a file becomes it is often well to take command of the file with one obstructed by Pawns of the Rooks IHE BISHOP want to ca stle on that open that as position to play in the early takes the Rook side not The BISHOP moves and captures diagonally in any direction over unoccupied squares In the following diagram 5 indicate the squares to which the Bishop may move A the spaces marked with a cross 8080 CHESS The Bishop is next to the Rook in power placed on squares of different colors and to squares of the same color IHE KNIGHT The KN moves of the Rook and Rook then the square move diagram 6 the Knight The Knight is next to the Bishop in power and some players prefer to a single Knight to a single Bishop are much stronger than two Knights if only for the very slighi Two Bishops Thus it will be seen tha of a rectangle composed of six squares the opposite color to the one on which it started the spaces marked with a cross indicate the squares the Bishop like a Bishop one sq from which the Knigh i may move YY A WA Y uare a eae gt _ eS A X Y uU Ub gu E m m m E GHT moves and captures in any direction by a movemen That is it moves which final squ
17. as developed the opening for the computer in which it resides Set displays as desired Once the game is started the computers will not respond to commands Enter Z RETURN on first Sol It should say What Enter E2E4 RETURN on second Sol The game will commence The first Sol displays itself as the computer and the second Sol as the player The second Sol displays itself as the computer and the first Sol as the player Therefore since the player s position is always at the bottom of the screen ach display will be the reverse of the other aee 8080 CHESS APPENDIX 1 CHESS PRIMER CHESS is a game in the play of which there is no element of chance It is played on a square called the chess board and divided into 64 souares colored liaht and dark alternately Each player shall play with a series of sixteen men one series to be light colored and called white and the other to be dark colored and called black The men in each series consist of 1 King 1 Queen 2 Bishops 2 Knights 2 Rooke 8 Pawns A Total The men shall be arranged on the chess board at the opening of the game as shown in diagram No 1 No 1 Reprinted from Crueke s Chess Primer published by Wm F Drueke amp Sons Grand Rapids Michigan U S A Al 1 8080 CHESS The symbols used on this and following diagrams represent the different pieces respectively a
18. ay move 8080 CHESS IHE NOTATION Both of the two mos I Descriptive and the Algebraic the descriptive sys English language we will confine ourselves to that the Knight are designated by their initials EST DES Ehe N board are if preferred they stand Federation universal usage of if necessary International Y Y NY Y Y 3 We Z 7 E The Bishop ud LHD AD V and Knight and Rook on Ulla A Y Zr yy yy Zu te TL QR QKT QB Q K KB KKT KR No 8 Des Echecs tem in books published in t system N HM LNN YA t widely used system of notation are recognized by the Because of the almost the The men except the Knight by Kt the King s side further designated by prefixing the let the corresponding men on the Queen s side by prefixing the letter Q Pawns are designated by prefixing the initial of the piece on whose file or by of the ter K and The The eight files counting consecutively left to right on the side of the chess board initially occupied by the whit and KR files respective OKt OB OQ The eight ranks are numbered for the white men chess board initially occupied by them K KB KKt men ar designated the ly to 8 from the side of and inversely for the black 1 8 from the side of the chess board initially occupied by Al 6 8080 CHESS OR t
19. ay move to any square adjoining the square he occupies and In the Y Z mM 7 EN m B B j 8080 CHESS Once during each game both the Player and the Opponent have the privilege of castling that is moving the King two squares either to the right or left and placing the Rook toward which he moved on the square over which the King has passed Castling can be consummated only when there are no intervening pieces when the King is not in check that is being attacked by a hostile man and only when neither the King nor the Rook have previously moved The King must never move over a square commanded by an opposing man The King is the most important piece as the loss of the King means the loss of the game In the opening and middle game the King has but little offensive power due in part to the circumscribed nature of his move and also to the risk of involving him in unnecessary danger In the end game however the King becomes a potent force for both offense and defense The novice should always remember that while the opening moves are primarily for the development of the pieces and though he should avoid premature attacks he must constantly be on guard against such strategy against his own King Except in cases of necessity it is seldom advisable to move the King early in the game If for no other reason this is true because it abrogates his right to castle
20. can be exacted ure has been made by a legal move option of the Opponent the Player shall make a legal move but if no such legal move can be the Player must either take the or make a legal move with his own man but if no such legal move can be move has been made no penalty can be exacted c If in the course of a game it is proved that an illegal made and not retracted the position existing immediately before th illegal move was made shall be reinstated and the game shall from that position be annulled 5 PENALTI ES The Opponent he has not Castling canno penalty a move illegality commit any penalty the position which shall be reins 6 CASTLI NG If can exact a penalty for an infraction of touched one of his own men after the infrac t be exacted as a penalty move which is illegal his right to ex ta ted tted by the Player shall be abro xisted before th If be continued the position cannot be reinstated the gam these act gated shall laws only if tion occurred the Opponent names as a penalty for the Before enforcing illegality occurred The person who gives the odds of a Rook may castle as though this Rook were on the board on the side from which the Rook has been removed object to the condition that this Rook s square is not occupied by any ither series other
21. command RPO R nable the player s castling by the command RP1 These castling commands are used 1 In continued games which have been reentered 2 In certain chess problems 3 When two computers are to play each other Refer to Appendix 1 Chess Primer for a glossary of chess terms 4 4 8080 CHESS 4 7 ILLEGAL MOVES If the player makes an illegal move the program questions WHAT Simply enter a legal move CAUTION If the player inadvertently puts his queen en prise the program will not give any courtesy it will promptly annihilate her 4 8 PROMOTING PAWNS To promote a pawn about to reach the 8th rank enter one of the following commands before the move which advances the pawn to the final rank Promote to a queen 05 Promote to a rook Q2 Promote to a bishop 04 Promote to a knight 203 4 9 PASSING YOUR TURN TO MOVE You may skip your move and let the computer move next by entering the command YOU This command is useful in setting up saved games and chess problems which are covered in Section 5 4 10 CONCEDING AND REMATCHES If you would rather not continue a game you may concede by entering the command X RETURN If you have conceded or if you have had the misfortune of having your king checkmated by a merciless machine the program will offer a rematch For Yes answer Y RETURN If No answer N RETURN
22. de with the maximum score In the example presented by Fig 6 1 the heavy arrows point out a path through the branch which the program has selected for its proposed development SECTION 7 On page 7 1 delete step 5 In step 8 insert a Z between and E2E4 The command is ZE2bE4 731043 page 2 of 3 9 78 No ECN COMPUTER MOVES NODE 1 NODE 2 NODE 3 1 PLY 1 AVAILABLE MOVES PLAYER MOVES at 5 10 E 2 4 COMPUTER Y e o e EU 2 PENS PLY 2 MOVES ai 1 1 l 1 PLAYER MOVES TERMINAL NODES PLY 4 AG SE cee da fate Seat eae ees Sah ee at CAPTURE PLY COMPUTER MOVES PLYS OE li a a See o 13 CAPTURE PLY L COMPUTER S MOVE C PLAYER S MOVE Fig 6 1 Look ahead Tree 731043 page 3 of 3 9 78 No ECN
23. eading the manual any further 8080 Chess is the chess player s genie the perfect opponent ready whenever you are as often as you like for as long as you want as difficult to beat as you wish seldom blundering never cheating tireless patient attentive 8080 Chess is a powerful versatile video display game for S 100 bus microcomputers The 8080 Chess program was designed and written for Processor Technology by Robert Arnstein of Dallas Texas The program has competed successfully in chess tournaments Besides playing a regular game as either white or black according to the international chess rules the 8080 Chess program can be controlled to provide different levels of opposition for players of varying degrees of proficiency It can be handicapped or play a handicapped player solve chess problems continue playing a game saved from a previous time show you what it is thinking and how many moves it considered before making its move It can even provide human spectators with a match between two chess robots The 8080 Chess program is contained in a standard CUTS format cassette The program requires 16K of memory Once loaded into memory it can be transferred to diskette using a Processor Technology Helios system 1 8080 CHESS SECTION 2 LOADING THE CASSETTE It is suggested that you load the program from cassette before you start
24. eces remaining do not constitute sufficient force to checkmate the opposing king A1 10 8080 CHESS IHE LAWS OF THESE LAWS were passed by the F I ng a meeting of the co Echecs duri CHESS SD E uncil at Venice International Federation Des in July 1929 Ihey are from the authorized edition of the official code as translated by the British Ches s Federati on in 1931 THE POS I ON OF The chess board shall be so placed b nearest corner square at their respectiv If in the course of colored that the ini tial IHE CHESS BOAR D ANI D THE MEN tween th chess board wrongly placed initial illegally reinstated and the gam If in the course of a game the number or position of the position immediat or immediately after a game position of the men on the board was incorrect lly the game shall be annulled right hands shall be it the men b two persons that the light be proved or the altered th resumed th ly befor refrom alteration occurred If this position cannot be must be ascertained the game shall be annulled and there shall be a replay 2 THE MOVE The choice of playing the first game with shall be determined by lot games the two persons shall play with the irrespective of the results of the the above la The firs
25. eful For use with the the Panasonic RQ 413AS or Realistic recorder at least a foot away from equipment containing power transformers picked up by 3 Keep th or other equipment which might generate magnetic fields the recorder as hum manufacturer S instructions 4 Use high tape tape heads quality brand nam 5 Bulk 6 Keep casset when not in use liquids ras tapes befor the tape 7 Experimentally determine th tone controls and use these set tape Poor tape can give poor results reusing want in a jumble of old file pieces noise level of tes in their protective pl Cassettes are vulnerable and physical abuse and preferably low noise tape heads cleaned and demagnetized in accordance with the high output rapidly wear down a recorder s lastic covers to dirt It can be hard to find the file you Bulk erasing also decreases th in a cool place high temperature most reliable settings for volume and tings only SAVE an empty Once you the microphone can be live while recording In some cases this can be done by inserting file named read its 8 On some cassette recorders through the AUX input Deactivate the mike in accordance with the manufacturer s instructions a dummy plug into the microphone jack 9 If you record more than one file on a side END
26. en setting the search depth For instructions for setting the depth control refer to subsection 6 1 643 SEARCH DISPLAYS 6 341 A Penny for Your Thoughts Computer To see what the computer is thinking when it performs the evaluation its move enter the command aS RETURN Commands must be entered during the player s move A game control command does not replace your move The displays shows the possible moves being acted out The speed of the display may be controlled by the number keys 1 through 9 Key 1 is the fastest speed at which the display can be shown key 9 is the slowest Remember that the search display will slow down the actual calculations consequently increasing the time the computer takes for its moves To turn off the display repeat the command during any of the player s subsequent moves This type of command is called a switch 6 3 2 How Many Nodes Did You Consider That Move By means of another game control command the hexidecimal equivalent of the number of terminal nodes analyzed by the program after each of its moves can be displayed The number is displayed in a little box which appears in place of the number 8080 of the initial display Refer to Fig 4 1 Display of a Game in Progress To display the number of terminal nodes analyzed just before you make you next move nter the command E RETURN To tur
27. he to them Thus referring to diagram 8 the black Rook in the upper right hand corner is on the King s Rook s eighth square or on KR8 reading from the white side of the chess board and is on the King s Rook s first square or on KR1 reading from the black side A move shall be recorded by the letter designating the man moved followed by the letter or letters and number designating the file the file and rank respectively of the square to which the man has been removed For instance Q KB4 means the Q is moved to the fourth square of the file of the King s Bishop When two men of the same series and denomination can be moved legally to the same square the letter or letters and number designating the file and number of the square which the moved man occupied shall be added in brackets to the letter designating the man moved For instance R KKt2 Kt4 means the R on the second square of the KKt file is moved to the fourth square of the same fil If an opposing man occupies the square to which a man is moved the designation of such opposing man shall be substituted for the designation of the square preceded by the symbol for capture but the latter designation stated as from the Player s side of the Chess board shall be added in brackets if otherwise the record could be interpreted as applying to more than one opposing man The following abbreviations will be found in common usage in C
28. hess literature and should be memorized by the student Castles KR or 0 0 Castles with the KR Short Castling Castles QR or 0 0 0 Castles with the QR Long Castling X Captures Ch Check Mate Check and Mate VALUE OF THE CHESSPERSONS Taking the worth of a pawn as unity the following is an estimate of the comparative mobility value of the persons Pawn Knight Bishop Rook Queen King N 0 01 Co WE O1 O1 N O1 Of course the King cannot be valued for trading because he is the object of the game Al 7 8080 CHESS IECHNICAL TERMS EN PRISE A piece is said to be en prise when it can be taken by a hostile piece or Pawn J ADOUBE or I ADJUST Used to inform the opponent that a piece is being touched for the purpose of adjustment and not with the intention of moving JE FORCED MOVE When a player has only one move at his disposal it is termed a forced move ILLEGAL MOVE or FALSE MOVE Any move which cannot be legally made such as castling after the King as been moved or moving a Knight like a Rook MINOR PIECES The Bishops and Knights are termed minor pieces to distinguish them from the Queen and the Rooks RANKS AND FILES The rows of horizontal squares are called ranks and the rows of vertical squares are called files GAMBIT A word derived from the Italian meaning to trip up in wrestling The word as used in chess phrase
29. ituated that he cannot be moved without going into check and when no other piece or Pawn can be moved A1 9 8080 CHESS SMOTHERED MATE or Philidor s Legacy occurs when the King is so hemmed in by his own men that he cannot move out which is the only piece that can administer this mate of check from a hostile Knight CHECKMATE This word is derived from the Persian Shah mat literally the King is dead This occurs when the King at the time in check is unable to relieve himself from this condition TO TAKE EN PASSANT OR IN PASSING When a Pawn exercises his privilege of moving two squares on his initial move an opponent s Pawn situated on the fifth square of an adjoining file may capture it by moving onto the square over which the Pawn has moved just as if he had stopped there DRAWN GAME When neither Player can checkmate his adversary the game is drawn The following are the instances in which this occurs a When the player cannot make a legal move and the King is not in check the King is then said to be stalemated b If the Player proves he can subject the Opponent s King to an endless series of checks C By reoccurrence of position when the same position occurs three times in the game and the same person is Player on each occasion and if such Player claims the draw before the posit tion is altered by further play otherwise no claim can be su
30. man of If a Player be must make that PAWN TAKING left move EN 8 The game shall be declared forfeited by the Player or GAMES FORFEITED PASSANT with no other move than to take a Pawn in passing a Wilfully upsets the board or disarranges th b Refuses to comply with a legal requirement c In the course of a game refuses to conform obey the rules made for the conduct of the game d Whether present or absent exceeds any time consideration of his moves A1 12 e men under these he the opponent who laws to the arrangements and to limit for the 8080 CHESS 9 THE UMPIRE OR BYSTANDERS A dispute on a question of fact may be submitted by agreement of the Player and Opponent to the decision of a disinterested bystander in which l be binding without the right of appeal case his decision shal 10 When putting the obligatory for the Player to advise check Opponent s King 11 COMPLETION OF MOVE A move is complete in check it is customary but NOT the opponent of this fact by saying a In moving from one square to another when the Player has quitted the man b In capturing when the captured man has been removed from the Board and the Player has quitted the man making the capture c In Castling when the Player has quitted the Rook d In promoting a Pawn when the Player ha
31. n off display repeat the command during any subsequent player s move Switch 6 4 8080 CHESS A 4 digit hexidecimal number representing the decimal number of terminal HEX NUMBERS 0 DIGIT POWER 16 3 DECIMAL FACTOR 4 096 256 number is converted to decimal as fol nodes appears in a box in the upper right area of the display The hex lows 16 2 16 1 16 0 16 1 2 3 4 5 6 7 9 2 9 A Be Wm Dr BE E 2 3 4 5256 38 9 LO dado E2 13 44 15 DECIMAL 0 INSTRUCTIONS Multiply the decimal equivalent of each digit position by the factor for that position and add the results EXAMPLES 1111 hex FFFF hex 4 096 61 440 256 3 840 16 1 4 369 nodes 240 15 65 535 nodes 8080 CHESS SECTION 7 CHESS ROBOTS PLAY EACH OTHER Two Sols can play each other communicating through their EIA serial interface ports Use the following procedure 1 2 3 4 5 6 7 8 Connect the J1 Serial Communication Interface connectors of the two Sols with a 3 conductor cable wired as follows Sol 1 Sol 2 Pin 7 to Pin 7 Pin 2 to Pin 3 Pin 3 to Pin 2 Enter B Black on first Sol Enter W White on second Sol Set desired depths Disable castling of both Sols otherwise the program will be lost when the first Sol castles The program is weighted to castle at the earliest opportunity after it h
32. ne sid interlock in the recorder will A piece of tape over the cavity An track of the position of files on the tte and set the counter te into the recorder to zero when Time the first 30 seconds and Always begin recording after this count Record the beginning and ending count of each file for Befor few cou written over 14 Th files on a casse of the tape and is read informal recorded th mp search no fur ty file called EN ther nts beyond the end of the e SOLOS CUTER command CATal tte tion will be displ with the tape will be able 15 much work purchased 1 do not despair tape same side of the counter readings Th fil sam tape at th tim sam recording a new file after other files Last file to ins Log can be used In SOLOS CUTER type CAT lt CR gt press PLAY on the recorder layed on D If you write down the counter readings and a brief description of the file to locate any file quickly as Before beginning work after any modification to the system SAVEing and GETting a short test program In addition to using the above procedures methodically the various ways in which programs may be recorded on tapes If you cannot read a file consistently may hav Processor Technology often records a second version When you first or CUTER so you will know exactly what A3 2 advance a ure
33. ology signifies a sacrifice usually a Pawn sacrifice for the purpose of obtaining an attack The Pawn thus sacrificed is called the gambit Pawn DOUBLED PAWN Pawns of the same color on the same file are called doubled Pawns ISOLATED PAWN A Pawn which cannot be supported by other Pawns and stands alone on a file is called an isolated Pawn PASSED PAWN A Pawn is called passed when there is no hostile Pawn to prevent its march to the eighth square MAN A term applicable to each King Queen Rook Bishop Knight and Pawn PIECE A term applicable to each man except a Pawn PINNED MAN A man that occupies a square between the King of the same color and an opposing piece that would otherwise be giving check to the King DISCOVERED CHECK Check given to the Opponent s King when the line of action of the checking piece is opened by the movement of another man of the same color DOUBLE CHECK Check given by the man moved in addition to the discovered check from another piece AN EXCHANGE The exchange by capture of identical men or of men of practically the same theoretical value A1 8 8080 CHESS WINNING OR LOSING THE EXCHANGE To exchange by capture a Bishop or Knight for a Rook is winning and of a Rook for Bishop or Knight is losing the Exchange CHECK The King is in check when he is attacked by a hostile piece or Pawn
34. on to an unoccupied square or to capture an occupied square Enter the coordinates of the from square where the chessperson is now followed by the coordinates of the to square the square to be occupied EXAMPLE f you wish to move P K4 type E2E4 and press RETURN Your selected move will be echoed in the display beneath the board and the person will move tentatively to the square selected The background of the square will flash alternately white to black or vice versa This is your chance to visualize your proposed move and give it final consideration before you commit yourself to it If you wish to retract the move press DEL Delete The move will be cancelled and you may enter a new move If you wish to execute your move press RETURN a second time The program will stop flashing the square and will record your move in the record columns 4 3 2 COMPUTER S MOVE The program will begin thinking over its own move A number displayed in the upper right corner of the screen will flash while the program is calculating its move This number represents the level of the game depth Refer to Sectiion 6 Game Depth Control and Display When the program has arrived at its move this number stops flashing the chessperson is moved on the board the move is recorded in the move columns and the number of the next pair of moves is displayed beside the move columns It s your move again
35. op of the page insert the letter I between the circumflex and the number of the rank on each rank For example the eighth rank is I8 B 6 1 1 Instructions for Setting the Depth Control On page 6 1 in the example insert the letter D between the circumflex and 41 The example is D41 RETURN 6 2 HOW THE PROGRAM FINDS IS MOVE In the second paragraph from the bottom of page 6 2 change preset default value 31 three one to preset default value 3 2 three two On page 6 3 delete the last sentence of the first paragraph Delete the second paragraph and Fig 6 1 Make a note to refer you to the substitute text and diagram which follow On page 6 4 delete the first paragraph 731043 page lof 3 9 78 No ECN SUBSTITUTE TEXT for Section 6 pages 6 3 and 6 4 A negative score is assigned it the position represented by a node favors the player A positive score is assigned if the position favors the computer Positions are evaluates on the basis of material and positional advantage In Fig 6 1 the depth is set to 3 2 or a total of 5 ply when a capture is found on the third ply or when a check occurs The program evaluates the branches springing from the ply 1 nodes one at a time starting from the terminal nodes which are at the lowest ply of the branch From the terminal nodes the program works backwards up the tree to the star
36. presenting the correct and incorrect checksum numbers Even though the checksum test was failed it may be possible to enter th program anyway by typing the carriage return key The bad data may not even be apparent if it is in a portion of the program you do not use It is best however to try to find and correct the problem causing the error so the checksum test is passed The error can be caused by the cassette inteface circuitry bad memory locations bad tape a faulty recording improper alignment or settings on the cassette recorder or other equipment problems A3 3 8080 CHESS APPENDIX 4 MOVE AND COMMAND SUMMARY REFERENCE Commands are preceded by a circumflex Press RETURN to enter all typed moves and commands MOVES AND MOVE COMMANDS To seleci To seleci white enter W RETURN black enter B RETURN To enter a move enter LetterNumberLetterNumber EXAMPLE P Q4 with From Square To Square player as white is D2D4 CL Castle Left CR Castle Right YOU Player skips a move and lets computer move PD5C6 Capture En Passant from D5 to C6 X Resign GAME CONTROL COMMANDS RPO Disable player s castling RPI Enable player s castling RPO Disable computer s castling RC Enable computer s castling Q5 Next Pawn reaching 8th rank
37. rching the terminal nodes branching from them STARTING POSITION COMPUTER MOVES NODE 1 NODE 2 NODE 3 UU y AVAILABLE HP MOVES PLAYER MOVES PLY1 COMPUTER MOVES amp 9 13 Es 89 En 5 7 5 MH 80 GI 50 gt PLAYER MOVES TERMINAL NODES PLY4 A E AS 31 40 CAPTURE PLY Fig 6 1 Look ahead Tree 6 3 8080 CHESS When each of the initial positions on ply 1 has received its score the program selects the move leading to the node having the highest score In Fig 6 1 therefore the program choses the third move as indicated by the arrow leading from the starting position This method of tree searching is called the minimax method 622 1 SETTING THE DEPTH OF THE TREE SEARCH The program is preset to a tree search depth of 32 This is not thirty two but three two With this setting the computer will move on the average in 2 to 3 minutes having analyzed up to about 15 500 nodes maximum With each ply the number of nodes analyzed is roughly 30 times the number analyzed on the previous ply This exponential increase with each ply of search added means also an exponential increase in time taken by the computer to run the search For example a depth setting of 44 takes the Sol about 2 to 3 hours per move Therefore unless you are Rip VanWinkle or have access to a time machine or a Cray 2 computer which emulates an 8080 it would behoove you to be careful wh
38. s A half move is one move by either the player or the computer A half move is referred to as a ply The value of the second digit is the number of additional plys the program will analyze upon finding a capture by either side The value of these two parameters can be set independently to either raise or lower the depth setting The higher the numbers the stronger the computer s move will be The lower the numbers the weaker an opponent the computer will be Note that for each additional ply added to the first parameter the time taken by the computer to reply increases approximately by a factor of 30 6 1 21 Instructions for Setting the Depth Control The depth command and other commands may be entered only when it is the player s move and before the player moves aS Dnm RETURN To set the search depth enter the command where D The code for DEPTH search The depth a digit in arabic numbers 1 through 9 m Added depth upon finding a capture by either side expressed as a digit 1 through 9 If m U DIU capture depth is unlimited 2 ll CAUTION There is no way of knowing how long the computer will take to move if the capture depth is set to U EXAMPLE 41 RETURN A depth of 4 ply plus one additional capture ply for a total of 5 ply on captures Maximum finite setting is 99 Maximum setting is 9U Minimum setting is 11 6 1
39. s follows White King eo Black King 17 Y A Y Queen Y Queen A Rook dal Rook Bishop ul Bishop A knight A Knight 4 Pawn i Pawn The men move to unoccupied squares excepting in making a capture Then they take the square vacated by the captured man The Knight is the only piece having the power to move over an occupied square The two exceptions to these rules taking a pawn en passant and castling will be taken up later in paragraphs explaining the moves of the King and the Pawn The board shall be so arranged that each Player shall have a white square in his right hand corner tely one move a the Player and alterna termed a time A capture is ff Cc replacing it wi when necessary piece or Pawn THE KING The KI following diagram th to occurs when the King the capturing avoid checkma The Player and the Opponent shall play The person whose turn it is to move is the other is termed d by removing the Opponen man te being at the time in check the Opponent t s man from the board and tures are optional except tion of checkmate or mate attacked by a hostile All cap The condi cannot be relieved from that condition NG can be moved captures in the same manner any unprotected opposing man the spaces marked with a cross indicate the squares 2 to which the King m
40. s replaced the Pawn by the selected piece and quitted the latter A1 13 8080 CHESS OPENI NG IN A BOOK of these proportions exhaustive analysis of the many openings in current use We do we have not the space to present an however desire to give an example of a few of the more common opening moves Tne only pieces available develop th Pawns as will give outlet book we shall on the first move are the Knights other pieces it is necessary to move the Pawns quick development is of prime importance to the greatest number of pieces many developing Pawn moves to choose from it is well first moving either the King s or the Queen s Pawns 1 THE CENTER GAMBIT WHITE BLACK Eie P K4 P K4 2 F 04 P x P 3 O x P Kt QB3 4 O K3 Kt B3 Si Kt QB3 B K2 6 B 02 P 04 2 THE KING S BISHOP S OPENING 1 P K4 P K4 2 P 04 P x P 3 B QB4 Kt KB3 4 P K5 P Q4 3 THE SCOTCH GAMBIT Jd P K4 P K4 Da Kt KB3 Kt QB3 3 P 04 P x P 4 B B4 Kt B3 Su P K5 P Q4 du THE SCOTCH GAME 1 P K4 P K4 2 Kt KB3 Kt QB3 3 P 04 P xP 4 Kt x P Kt B3 5 Kt QB3 B Kt5 6 Kt x Kt KtP x Kt 7 B Q3 P 04 Al 14 and for the purpose of confine ourselves to a few of the openings that start In order to first Since to move such There are not this with 8080 CHESS
41. ss board game is still worthy of our consideration That is the chess problem like an end game The pieces ar is possible in a given number of moves checkmate the black A chess problem consists of a position on the board somewhat arranged in such a way that a checkmate Usually the white men are to There may be many variations due to the lines of defense adopted by the black men but if it be a good problem that will bring about the desired results The illustrative problem that w solve but and may giv WHITE K on KR8 Rs on KKi B on OR7 t7 and Q2 Kt on KK tl hav selected is not BLACK on on on on UU IO A White to move and mate in two moves Al 16 KR7 KKt7 KR8 KR5 there can be but one first move a difficult one to will serve as an example of what constitutes a chess problem the reader an evening s enjoyment 8080 CHESS Successful and reliable results with cassett require a good deal of care methods and you need to know what to expect when you manufacturer s tape or your own The following methods ar 1 Use only a recorder recommended for digital usage Processor Technology Sol or CUTS APPENDIX 3 ABOUT CASSETTE RECORDERS AN D CASSETTE FI You need to use consistent try to read a recommended CTR 21 is recommended 2 Keep th recorders and cassette files and car
42. ss terminology g 8080 CHESS BUB CHESS Processor Technolog A B C D E F 6 H BS RNBQKBENR iG PPPPPPPP 7 CHESS 1 8 MOD H DO YOU WANT BLACK B OR WHITE M Display The Initial Pages oS 3 2 8080 CHESS Each chessperson is Pawn Knight Bishop Rook Queen King represented by a single letter of the alphabet KOZU SZL The Complexion of the Chesspersons If your video is set video the player s background the comp dark background If your video is set video the player s background the comp white background This color indicatin which shows whether to display white letters on a black screen revers persons are displayed as black letters on a white uter s persons are displayed as white letters on a to display black letters on a white screen regular persons are displayed as white letters on a black uter s persons are displayed as black letters on a g background of a chessperson covers up the display the square occupied by the person is light or dark You can determine wh an adjoining square square ther an occupied square is light or dark by checking which is unoccupied and working back to the occupied 3 23 AUXILIARY D As a helpful suggest designed video displ and interpreting the ordinary chess board You can then act out saving games ISPLAY ion to ease the strain of peering at the economically
43. stained For the purpose of this clause there shall be no distinction between the King and Queen s Rooks and Knights or between the original pieces and pieces of the same denomination and color obtained through the promotion of Pawns d By mutual agreement but only after 30 moves have been made with the Black men e The game shall be declared drawn if the Player proves that 50 moves have been made on each side without checkmate having been given and without any man having been captured or Pawn moved f Either the Player or the Opponent may at any period of the game demand that the other checkmate him in 50 moves subject to the conditions attached in e If checkmate is not given in 50 moves the game shall be declared drawn Nevertheless the count of 50 moves shall begin again after each capture of any man and after each movement of a Pawn Exception shall be made for certain positions where theoretically more than 50 moves are necessary to force a checkmate and in this case a number of moves double the number established by theory as being necessary for this object shall be allowed in lieu of the 50 The draw must be claimed by either the Player or the Opponent immediately when the stipulated number of moves in Conditions e and or f of the particular case is completed without checkmate being given and not at any later period g Lack of Force of pi
44. t shall mov mo w Shall not be reckoned in applying ve shall be with the white men one move at a time alternately 3 TOUCH If the playe one of h 2 one of h 3 one of h latter with Opponent may take with an capture can the moves in be exacted ILLEGAL ING MEN r touch is own men is opponen is own men the former or by agreement games but games ann this rule and thereaft he must move it t s men he mu and one of h requir y one of h b ffect ither tha is men a ch ch if such capture be a legal move th dicated in MOVES If a Player makes an illegal the fact before touching any of his own men retracted and the game shall d legally this paragraph can be made legally Al st take it is Opponent s men e player shall move the man e Player s option e Opponent s man touched 11 the white men or the black men and in a match of two or more two series alternately ulled according to r the players he must take the If mot touched with which the If none of no penalty can the Or move and the Opponent draws his attention to the illegal move must be be continued as follows 8080 CHESS a made no penal b If a capt Opponent s man touched at the When a capture has not been made with the man he has moved illegally ty
45. tem of notation This is called the algebraic system of notation Counting up from the player s side the ranks horizontal rows of squares are numbered 1 through b on both sides of the board The files vertical columns of squares are lettered alphabetically on both the top and bottom of the board reading from the player s left to right A through H For example the square designated in international notation as white s R4 is identified as E4 black s K4 is E5 Note that the letter is always first Note also that each square has a univocal location that is it is the same for black and white whereas international notation is relative to the black or white side of the board S Display of the Checkerboard Pattern If your video is set to display black letters on a white screen the dark squares will be screened with dark dots If your video displays white letters on a dark screen the dark squares will be screened with white dots 342 IHE CONTENDERS UNIMPORTANT NOTE In deference to the queen as well as to some of the players who may be equal rights advocates we shall deviate from the international terminology which calls the chess figures collectively men and a single piece or pawn a man By the way a piece is correctly defined as to exclude pawns Refer to Appendix 1 Chess Primer for an explanation of international notation and che
46. that it will not be to generate a list of all rewind to the ginning As the header of each file the screen If you have suggested you will know when to the catalog information along you test by This could prevent the loss of need to know you have you and suspect th n recorded elsewh tape itself b re on the later on the CATalog it with SOLOS Write down the tape get a tape it contains 8080 CHESS 2 An empty file named END is sometimes placed at the end of the recorded portion of a tape When SOLOS CATalogs a file the file header information is displayed as soon as the beginning part of the file passes the tape head but nothing is displayed when th nd of the program passes by If another filename such as END is displayed you know you have just passed the end of the previous file 3 Some of the programs supplied by Processor Technology contain a checksum test within their code in addition to the checksum test which SOLOS performs When a program containing this test is first executed after loading the checksum test reads all of the program in memory and calculates a checksum number which is compared with a correct value If the numbers match the program in memory is correct Nothing is displayed when the numbers match but if they do not match the message CHECKSUM TEST FAILED or a similar message is displayed The message may be followed by two numbers re
47. ting position If the terminal node of a branch results from a player s move as occurs on even numbered plys the program assumes tie player shall have chosen his or her strongest move on the previous ply therefore th program takes the score of the terminal node having the lowest and backs this score up to the next higher ply assigning the score to the parent node which represents the position from which the player would move If the terminal node is a position resulting from the computer s move as occurs on odd numbered plys naturally the program chooses the highest scoring terminal none and assigns the score to the terminal nodes s parent node which represents the position from which the computer would move This tree search method of alternately choosing minimium or maximum Scores depending on whose move it is is called the minimax method After backing up the score of the terminal nodes to the next higher ply the program looks horizontally on the new ply and evaluates the other nodes belonging to the same branch if any Then it continues backing up the tree using the minimax method until the intial node on ply 1 has been evaluated Then it examines the next branch in the same manner When each of the ply 1 nodes has been scored the program is now back to real time Since it is the computer s move the program chooses the ply 1 no
48. ve which it displays on the board and records the notation of the move numbered 01 in the column titled COMPUTER 4 2 MOVES AND COMMANDS Simple chess moves such as moving or capturing in the usual manner are entered by typing an alphanumeric code and pressing RETURN Complex moves such as castling and en passant are executed by commands Commands are alphanumeric codes preceded by a circumflex Not all commands are moves There are two types of commands move commands described in this section and game control commands described in Section 5 Chess Problems and Saving Games and Section 6 Game Depth Control and Display Commands may be made only when it is your move Only move commands replace your regular move Game control commands ar ntered when it is the player s move just before the player s move Both moves and commands must be followed by pressing RETURN The program will acknowledge the RETURN by placing a period after the command 4 1 8080 CHESS CHESS 1 8 MOD 0 8068 CHESS DO YOU WANT BLACK B OR WHITE M Processor Technolog A B C D E F 6 H PLAYER COMPUTER BRN ZKINR tB DL EA EVES PPP ZPPP 2 GIF3 D7D5 JL LM 43 E4DS D8Do jd DeD4 C864 A5 Fike G4F3 EF SB4CH AT C3 ESE 9 CR EdF 49 DIF3 DoF 18 G2F3 Bade Fig 4 1 Display of a Game in Progress 4 2 8080 CHESS 4 3 MOVING TO UNOCCUPIED SQUARES 4 3 1 YOUR MOVE To move a pers
49. will become a Queen Q2 Next Pawn reaching 8th rank will become a Rook O4 Next Pawn reaching 8th rank will become a Bishop O3 Next Pawn reaching 8th rank will become a Knight InXXXXXXXX Position computer s persons on rank n of board Where X one of the following P Pawn R Rook Q Queen B Bishop N Knight K King Space bar Vacant To position player s persons press CONTROL simultaneously while entering the character representing the person Dnm Set depth to n added capture depth to m EXAMPLE D34 3 ply plus 4 more ply on captures 7 ply on captures If m U EXAMPLE D3U capture depth is unlimited aD Display search Switch E Display number of end nodes looked at in hex Switch A4 1 8080 CHESS Processor Technology Processor Technology 7100 Johnson Industrial Drive 415 829 2600 Corporation Pleasanton CA 94566 Cable Address PROCTEC 8080 CHESS UPDATE 731043 Pleas nter the following changes into your manual The changes are keyed to the Section of the manual in which they occur 4 6 CASTLING When two computers are being set up to play each other disabling their castling is no longer necessary The computers will castle when ready and will continue playing On page 4 4 of the manual Section 4 6 delete the second line from the bottom 3 When two computers are to play each other Seil SAVING GAMES On page 5 2 in the example at the t
Download Pdf Manuals
Related Search