20 PRINT "GREETINGS PROFESSOR HIPO";
30 PRINT "........"
100 PRINT "SHALL WE PLAY A GAME?"

110 PRINT
120 PRINT "YOU HAVE THE OPPORTUNITY OF TRYING TO BEAT THE COMPUTER"
130 PRINT "AT TIC-TAC-TOE, ENTER YOUR MOVES AS FOLLOWS:"
140 PRINT

150 DIM C(11)
160 DIM D(11)
170 FOR K = 1 TO 11
180 READ C(K), D(K)
190 NEXT K

200 PRINT "...ROW NUMBER...COMMA...COLUMN NUMBER..."
210 PRINT
220 PRINT "ROWS ARE HORIZONTAL(ACROSS)...COLUMNS  ARE VERTICAL(UP + DOWN)"

230 DIM B(9)
240 DIM A(3, 3)
250 PRINT
260 PRINT "NEW GAME STARTED NOW............................"

270 FOR J = 1 TO 3
280 FOR I = 1 TO 3
290 LET A(I, J) = 0
300 NEXT I
301 LET I = I - 1
310 NEXT J
311 LET J = J - 1
320 LET Z = 0

330 PRINT "YOUR MOVE",
340 INPUT R, C
341 R = ABS(R)
342 C = ABS(C)
350 PRINT

360 IF R > 3 THEN 620
370 IF C > 3 THEN 620
380 IF A(R, C) <> 0 THEN 620

390 LET A(R, C) = -1
400 GOSUB 1660
410 IF Z = 1 THEN 2070
420 REM MACHINE MOVE...
430 GOSUB 1100
440 REM TEST  FOR GAME WIN
450 GOSUB 1660
460 IF Z = 0 THEN 650
470 REM PRINT GAME BOARD....
480 GOTO 490
490 PRINT
500 FOR K = 1 TO 3
510 LET B = A(K, 1)
520 LET D = A(K, 2)
530 LET F = A(K, 3)
540 GOSUB 840
550 IF K > 2 THEN 570
560 PRINT "**************"
570 NEXT K
571 LET K = K - 1
580 PRINT
590 IF Z <> 0 THEN GOTO 2070
600 GOTO 330
610 STOP
620 PRINT "---- ILLEGAL MOVE -- TRY AGAIN ----"
630 PRINT
640 GOTO 330
650 LET T2 = 0
660 FOR J = 1 TO 3
670 FOR I = 1 TO 3
680 IF A(I, J) <> 0 THEN 700
690 LET T2 = T2 + 1
700 NEXT I
701 LET I = I - 1
710 NEXT J
720 IF T2 > 0 THEN GOTO 750
730 GOSUB 1340
740 GOTO 480
750 IF T2 > 1 THEN 480
760 FOR J = 1 TO 8
770 IF B(J) = -2 THEN GOTO 800
780 NEXT J
781 LET J = J - 1
790 GOTO 730
800 GOSUB 2000
810 GOTO 480
820 REM PRINT TIC-TAC-TOE BOARD ROW.....
830 REM
840 IF B <> 0 THEN GOTO 910
850 PRINT "    * ";
860 IF D <> 0 THEN 940
870 PRINT "    * ";
880 IF F <> 0 THEN 970
890 PRINT "  "
900 GOTO 1070
910 IF B > 0 THEN 1000
920 PRINT "YOU * ";
930 GOTO 860
940 IF D > 0 THEN 1020
950 PRINT "YOU * ";
960 GOTO 880
970 IF F > 0 THEN 1040
980 PRINT "YOU"
990 GOTO 900
1000 PRINT "PDP * ";
1010 GOTO 860
1020 PRINT "PDP * ";
1030 GOTO 880
1040 PRINT "PDP"
1050 GOTO 900
1060 REM PRINT LEGENDS..
1070 PRINT "    *     * "
1080 RETURN
1090 REM PROGRAM TO MAKE MOVE FOR MACHINE...
1100 LET M = INT(3.33 * RND(1))
1110 LET N = INT(3.33333 * RND(1))
1120 IF M = 0 THEN 1100
1130 IF M > 3 THEN 1100
1140 IF N = 0 THEN 1100
1150 IF N > 3 THEN 1100
1160 LET C(2) = M
1170 LET D(2) = N


1180 LET C(3) = N
1190 LET D(3) = M
1200 FOR I = 1 TO 8
1210 IF B(I) > 1 THEN GOTO 1370
1220 NEXT I
1221 LET I = I - 1
1230 FOR I = 1 TO 8
1240 IF B(I) < -1 THEN 1370
1250 NEXT I
1251 LET I = I - 1
1260 IF R + C = 0 THEN 1550
1270 FOR K = 1 TO 11
1280 LET I = C(K)
1290 LET J = D(K)
1300  IF A(I, J) <> 0 THEN 1330
1310 LET A(I, J) = 1
1320 GOTO 1360
1330 NEXT K
1331 LET K = K - 1
1340 PRINT " ... TIE GAME ... "
1350 LET Z = 3
1360 RETURN

1370 IF I > 3 THEN 1440
1380 FOR J = 1 TO 3
1390 IF A(I, J) = 0 THEN 1420
1400 NEXT J

1401 LET J = J - 1
1410 GOTO 1360
1420 LET A(I, J) = 1
1430 GOTO 1360
1440 IF I > 6 THEN 1510
1450 FOR J = 1 TO 3
1460 IF A(J, I - 3) = 0 THEN 1490
1470 NEXT J
1471 LET J = J - 1
1480 GOTO 1360
1490 LET A(J, I - 3) = 1
1500 GOTO 1360
1510 IF I > 7 THEN 1550
1520 FOR J = 1 TO 3
1530 IF A(J, J) = 0 THEN 1590
1540 NEXT J


1541 LET J = J - 1
1550 IF A(1, 3) = 0 THEN 1610
1560 IF A(3, 1) = 0 THEN 1630
1570 LET A(2, 2) = 1
1580 GOTO 1360
1590 LET A(J, J) = 1
1600 GOTO 1360
1610 LET A(1, 3) = 1
1620 GOTO 1360
1630 LET A(3, 1) = 1
1640 GOTO 1360
1650 REM PROGRAM TO TEST  FOR GAME WINNER...
1660 LET T1 = 0
1670 FOR J = 1 TO 9
1680 LET B(J) = 0
1690 NEXT J
1691 LET J = J - 1
1700 FOR J = 1 TO 3
1710 FOR I = 1 TO 3
1720 IF A(J, 1) <> A(J, I) THEN 1750
1730 NEXT I
1731 LET I = I - 1
1740 LET T1 = A(J, I)
1750 NEXT J
1751 LET J = J - 1
1760 FOR J = 1 TO 3
1770 FOR I = 1 TO 3
1780 IF A(1, J) <> A(I, J) THEN 1810
1790 NEXT I
1791 LET I = I - 1
1800 LET T1 = A(I, J)
1810 NEXT J
1811 LET J = J - 1
1820 IF A(1, 1) = A(3, 3) THEN 1930
1830 IF A(3, 1) = A(1, 3) THEN 1970
1840 IF T1 <> 0 THEN 1990
1850 FOR J = 1 TO 3
1860 FOR I = 1 TO 3
1870 LET B(J) = B(J) + A(J, I)
1880 LET B(J + 3) = B(J + 3) + A(I, J)
1890 NEXT I
1900 NEXT J
1901 LET J = J - 1
1910 LET B(7) = A(1, 1) + A(2, 2) + A(3, 3)
1920 RETURN

1930 IF A(2, 2) = A(3, 3) THEN 1950
1940 GOTO 1830
1950 LET T1 = A(2, 2)
1960 GOTO 1840
1970 IF A(2, 2) = A(1, 3) THEN 1950
1980 GOTO 1840
1990 IF T1 > 0 THEN 2030

2000 PRINT " ... YOU  WIN THIS TIME ..."
2010 LET Z = 1
2020 GOTO 1850

2030 PRINT " ... THE PDP-8 WINS THIS TIME ..."
2040 LET Z = 2
2050 GOTO 1850
2060 REM END OF TEST WINNER PROGRAM..........

2070 PRINT "DO YOU WANT TO PLAY ANOTHER GAME: YES(1), NO(0)"
2080 INPUT X1
2090 IF X1 = 1 THEN GOTO 250
2100 IF X1 = 0 THEN GOTO 2130
2110 PRINT "I SAID ONE OR ZERO: TRY AGAIN",
2120 GOTO 2080

2130 PRINT
2135 PRINT "----------------------------------------"
2136 PRINT "A STRANGE GAME."
2137 PRINT "THE ONLY WINNING MOVE IS"
2138 PRINT "NOT TO PLAY."
2139 PRINT "HOW ABOUT A NICE GAME OF CHESS?"


2140 GOTO 2160

2150 DATA 2,2,0,0,0,0,1,1,3,3,1,3,3,1,1,2,3,2,3,2,3,1

2160 REM CHAIN "DEMON "
2170 END