!***************************************************************************!
!									    !
!				   OTHELO				    !
!			 Othello for the Alpha Micro			    !
!									    !
!			  Author: David F. Pallmann			    !
!									    !
!***************************************************************************!

STORAGE:
	MAP1 BOARD(8,8), F, 6		!board array
	MAP1 VALUE(8,8), F, 6		!positional value array
	MAP1 I, F, 6			!temporary
	MAP1 J, F, 6			!temporary
	MAP1 ROW, F, 6			!current row
	MAP1 COL, F, 6			!current column
	MAP1 FLAG, F, 6			!flag used internally by subroutines
	MAP1 WARN, F, 6			!flag used to warn of corner give-a-way
	MAP1 ROWDIR, F, 6		!vertical direction of travel
	MAP1 COLDIR, F, 6		!horizontal direction of travel
	MAP1 TESTROW, F, 6		!sample row
	MAP1 TESTCOL, F, 6		!sample column
	MAP1 NEWROW, F, 6		!new row
	MAP1 NEWCOL, F, 6		!new column
	MAP1 COLOR, F, 6		!current color (1=human, 2=alpha)
	MAP1 FLIPS, F, 6		!number of flips from move
	MAP1 TESTFLIPS, F, 6		!number of flips in one direction
	MAP1 MOVE, S, 10		!move text
	MAP1 HIGHFLIPS, F, 6		!highest #flips
	MAP1 BESTROW, F, 6		!row of best move encountered
	MAP1 BESTCOL, F, 6		!column of best move encountered
	MAP1 HDISCS, F, 6		!number of discs - human
	MAP1 ADISCS, F, 6		!number of discs - alpha
	MAP1 SCORE, F, 6		!score of move (flips + pos value)
	MAP1 HIGHSCORE, F, 6		!score of best move encountered

CONSTANTS:
	MAP1 EMPTY, F, 6, 0		!empty square
	MAP1 HUMAN, F, 6, 1		!human disc (O)
	MAP1 ALPHA, F, 6, 2		!alpha disc (@)

REM******************
REM*   INITIALIZE   *
REM******************
REM LOAD POSITIONAL VALUE ARRAY

INITIALIZE:
	FOR I = 1 TO 8
	    FOR J = 1 TO 8
		READ VALUE(I,J)
	    NEXT J
		NEXT I

	DATA 99,00,80,80,80,80,00,99
	DATA 00,00,00,00,00,00,00,00
	DATA 80,00,40,30,30,40,00,80
	DATA 80,00,30,00,00,30,00,80
 	DATA 80,00,30,00,00,30,00,80
	DATA 80,00,40,30,30,40,00,80
	DATA 00,00,00,00,00,00,00,00
	DATA 99,00,80,80,80,80,00,99

REM**************
REM*   SCREEN   *
REM**************
REM SET UP SCREEN

SCREEN:	PRINT TAB(-1,0);
	PRINT TAB(-1,12);
	PRINT TAB(1,12); "* OTHELLO *";
	PRINT TAB(-1,11);
	FOR I = 1 TO 8
	    PRINT TAB(I*2+1,1); CHR(I+64);
	    PRINT TAB(19,I*4); STR(I);
	    NEXT I
	PRINT TAB(7,50); "HUMAN MOVE";
	PRINT TAB(10,50); "HUMAN DISCS";
	PRINT TAB(13,50); "ALPHA MOVE";
	PRINT TAB(16,50); "ALPHA DISCS";

REM**************
REM*  NEW'GAME  *
REM**************
REM SET UP SCREEN FOR NEW GAME

NEW'GAME:
	FOR I = 1 TO 8
	    FOR J = 1 TO 8
		PRINT TAB(I*2+1,J*4); ".";
		BOARD(I,J) = EMPTY
		NEXT J
	    NEXT I
	PRINT TAB(-1,12);
	PRINT TAB(9,16); "O   @"
	BOARD(4,4) = HUMAN : BOARD(4,5) = ALPHA
	PRINT TAB(11,16); "@   O";
	BOARD(5,4) = ALPHA : BOARD(5,5) = HUMAN
	HDISCS = 2
	ADISCS = 2
	PRINT TAB(11,55); SPACE(2);
	PRINT TAB(17,55); SPACE(2);

REM******************
REM*   HUMAN'MOVE   *
REM******************
REM GET, VERIFY, AND MAKE HUMAN MOVE

HUMAN'MOVE:
	IF HDISCS+ADISCS=64 THEN GOTO END'GAME
	PRINT TAB(8,55);
	INPUT LINE MOVE
	PRINT TAB(23,1); TAB(-1,9);
	IF UCS(MOVE)="PASS" THEN GOTO ALPHA'MOVE
	IF LEN(MOVE)<>2 THEN GOTO INVALID
	NEWROW = ASC(MOVE[1;1])-64
	IF NEWROW<1 OR NEWROW>8 THEN GOTO INVALID
	NEWCOL = MOVE[2;1]
	IF NEWCOL<1 OR NEWCOL>8 THEN GOTO INVALID
	IF BOARD(NEWROW,NEWCOL)<>EMPTY THEN GOTO INVALID
	COLOR = HUMAN
	ROW = NEWROW : COL = NEWCOL
	CALL CHECK'MOVE
	IF FLIPS=0 THEN GOTO INVALID
	PRINT TAB(NEWROW*2+1,NEWCOL*4); "O";
	BOARD(NEWROW,NEWCOL) = COLOR
	CALL MAKE'MOVE
	IF WARN=1 THEN PRINT TAB(23,1); "NOT YOUR BEST MOVE";
	HDISCS = HDISCS+FLIPS+1
	ADISCS = ADISCS-FLIPS
	PRINT TAB(11,55); STR(HDISCS); "  ";
	PRINT TAB(17,55); STR(ADISCS); "  ";
	GOTO ALPHA'MOVE

INVALID:
	PRINT TAB(23,1); "INVALID";
	GOTO HUMAN'MOVE

REM******************
REM*   ALPHA'MOVE   *
REM******************
REM MAKE COMPUTER'S MOVE

ALPHA'MOVE:
	PRINT TAB(23,1); "THINKING";
	HIGHFLIPS = 0
	HIGHSCORE = 0
	BESTROW = 0 : BESTCOL = 0
	COLOR = ALPHA
	FOR ROW = 1 TO 8
	    FOR COL = 1 TO 8
		IF BOARD(ROW,COL)<>EMPTY THEN GOTO ALPHA'NEXT
		CALL CHECK'MOVE
		IF FLIPS=0 THEN SCORE = 0 : GOTO COMPARE

REASON:		SCORE = FLIPS+VALUE(ROW,COL)
		IF WARN=1 THEN SCORE = 1
		IF ROW=1 THEN CALL ROW'ADJUST
		IF ROW=8 THEN CALL ROW'ADJUST
		IF COL=1 THEN CALL COL'ADJUST
		IF COL=8 THEN CALL COL'ADJUST

COMPARE:	IF SCORE>HIGHSCORE THEN &
		   HIGHFLIPS = FLIPS : HIGHSCORE = SCORE :&
		   BESTROW = ROW : BESTCOL = COL

ALPHA'NEXT:
	    NEXT COL
	NEXT ROW
	PRINT TAB(23,1); TAB(-1,9);
	IF HIGHSCORE=0 THEN PRINT TAB(23,1); "ALPHA CAN'T MOVE"; : GOTO HUMAN'MOVE
	ROW = BESTROW : COL = BESTCOL
	PRINT TAB(ROW*2+1,COL*4); "@";
	BOARD(ROW,COL) = COLOR
	PRINT TAB(14,55); CHR(ROW+64); STR(COL);
	CALL MAKE'MOVE
	ADISCS = ADISCS+FLIPS+1
	HDISCS = HDISCS-FLIPS
	PRINT TAB(11,55); STR(HDISCS); "  ";
	PRINT TAB(17,55); STR(ADISCS); "  ";
	PRINT TAB(23,1); "YOUR MOVE";
	GOTO HUMAN'MOVE

REM****************
REM*   END'GAME   *
REM****************
REM END OF GAME

END'GAME:
	PRINT TAB(23,1); TAB(-1,9);
	IF HDISCS<ADISCS THEN PRINT "LOST";
	IF HDISCS=ADISCS THEN PRINT "TIE";
	IF HDISCS>ADISCS THEN PRINT "WON";
	PRINT " GAME";
	PRINT TAB(23,50); "CARE FOR ANOTHER? ";
	INPUT LINE MOVE
	PRINT TAB(23,1); TAB(-1,9);
	IF UCS(LEFT(MOVE,1))="Y" THEN GOTO NEW'GAME
	END

REM******************
REM*   CHECK'MOVE   *
REM******************
REM ON ENTRY:  ROW = ROW TO TEST;  COL = COL TO TEST;  COLOR = MOVER'S COLOR
REM ON EXIT:   FLIPS = #FLIPS MOVE WILL RETURN

CHECK'MOVE:
	FLAG = 0
	GOTO MOVE

REM*****************
REM*   MAKE'MOVE   *
REM*****************
REM ON ENTRY:  ROW = ROW TO TEST;  COL = COL TO TEST;  COLOR = MOVER'S COLOR
REM ON EXIT:   FLIPS = #FLIPS MADE

MAKE'MOVE:
	FLAG = 1

MOVE:	FLIPS = 0
	WARN = 0
	FOR ROWDIR = -1 TO 1
	    FOR COLDIR = -1 TO 1
		IF ROWDIR<>0 OR COLDIR<>0 THEN &
		   CALL LINEAR :&
		   FLIPS = FLIPS+TESTFLIPS
		NEXT COLDIR
	    NEXT ROWDIR
	RETURN

REM*************
REM*   LINEAR  *
REM*************
REM SUBROUTINE USED BY CHECK'MOVE: AND MAKE'MOVE:
REM
REM ON ENTRY: ROW/COL = ROW/COL TO TEST;  ROWDIR/COLDIR = MOVE DIRECTION;
REM           COLOR = MOVER COLOR
REM ON EXIT:  TESTFLIPS = #FLIPS GENERATED

LINEAR:
	TESTROW = ROW
	TESTCOL = COL
	TESTFLIPS = 0

LINEAR'1:
	TESTROW = TESTROW + ROWDIR
	TESTCOL = TESTCOL + COLDIR
	IF TESTROW<1 THEN GOTO LINEAR'FAIL
	IF TESTROW>8 THEN GOTO LINEAR'FAIL
	IF TESTCOL<1 THEN GOTO LINEAR'FAIL
	IF TESTCOL>8 THEN GOTO LINEAR'FAIL
	IF BOARD(TESTROW,TESTCOL)=EMPTY THEN GOTO LINEAR'FAIL
	IF BOARD(TESTROW,TESTCOL)=COLOR THEN GOTO LINEAR'COLOR

LINEAR'OTHER:
	TESTFLIPS = TESTFLIPS+1
	IF ROW=2 AND COL=2 AND BOARD(1,1)=EMPTY THEN WARN = 1
	IF ROW=2 AND COL=7 AND BOARD(1,8)=EMPTY THEN WARN = 1
	IF ROW=7 AND COL=2 AND BOARD(8,1)=EMPTY THEN WARN = 1
	IF ROW=7 AND COL=7 AND BOARD(8,8)=EMPTY THEN WARN = 1
	GOTO LINEAR'1

LINEAR'FAIL:
	TESTFLIPS = 0
	RETURN

LINEAR'COLOR:
	IF FLAG=0 THEN RETURN
	IF TESTFLIPS=0 THEN RETURN
	ROWDIR = -ROWDIR
	COLDIR = -COLDIR
	FOR I = 1 TO TESTFLIPS
	    TESTROW = TESTROW+ROWDIR
	    TESTCOL = TESTCOL+COLDIR
	    BOARD(TESTROW,TESTCOL) = COLOR
	    PRINT TAB(TESTROW*2+1,TESTCOL*4); MID("O@",COLOR,1);
	    NEXT I
	ROWDIR = -ROWDIR
	COLDIR = -COLDIR
	RETURN

ROW'ADJUST:	IF COL<2 OR COL>7 THEN RETURN
		IF (BOARD(ROW,COL-1)=(3-COLOR) AND BOARD(ROW,COL+1)=EMPTY) OR &
		   (BOARD(ROW,COL-1)=EMPTY AND BOARD(ROW,COL+1)=(3-COLOR)) THEN &
		   SCORE = 1
		RETURN

COL'ADJUST:	IF ROW<2 OR ROW>7 THEN RETURN
		IF (BOARD(ROW-1,COL)=(3-COLOR) AND BOARD(ROW+1,COL)=EMPTY) OR &
		   (BOARD(ROW-1,COL)=EMPTY AND BOARD(ROW+1,COL)=(3-COLOR)) THEN &
		   SCORE = 1
		RETURN

	END