This is Tic-Tac-Toe 81 v2.1 By Chad Kuboviak.  It is fully functional.  This version is one and two player, and the computer is pretty good.  However, it uses all three of the 81's matricies.  But, it is still pretty neat.  Please note the note at the end.  You can distribute the program as much as you like, as long as the about screen stays with it.  ˆ stands for theta.  » stands for the Sto> key.  Have fun!

Prgm1:GO.EXE
Norm
Rad
Function
Grid Off
[C](5,1)»Xmin
[C](5,2)»Xmax
0»Xscl
[C](5,3)»Ymin
[C](5,4)»Ymax
0»Yscl
1»Xres
ClrHome
Disp "    WELCOME"
Disp "      TO"
Disp " TIC-TAC-TOE 81"
Pause
Lbl 9
ClrHome
Disp "MAIN MENU-"
Disp "1-PLAY
Disp "2-INSTRUCTIONS
Disp "3-ABOUT
Disp "4-END"
Input A
If A=4
End
If A=1
Goto A
If A=3
Goto B
If A=2
Goto C
Goto 9
Lbl C
ClrHome
Disp "ENTER THE NUMBEROF THE SQUARE   YOU WANT TO GO  IN.THE SQUARES  ARE NUMBERED-"
Disp "123,456,789"
Pause
Goto 9
Lbl B
ClrHome
Disp " TIC-TAC-TOE 81"
Disp " V2.1  12/10/97"
Disp "BY-CHAD KUBOVIAK"
Pause
Goto 9
Lbl A
0»[A]
O»[B]
ClrDraw
Line([C](2,3),[C](2,4),[C](2,5),[C](2,6
Line([C](3,1),[C](3,2),[C](3,3),[C](3,4
Line([C](3,5),[C](3,6),[C](4,1),[C](4,2
Line([C](4,3).[C](4,4),[C](4,5),[C](4,6
Prgm2
Goto 9


Prgm2:TURN
Lbl G
ClrHome
Disp "1 OR 2 PLAYERS?"
Input [B](4,2
If 3<[B](4,2
Goto G
If 2=[B](4,2
Goto X
Lbl H
ClrHome
Disp "WANT TO GO      FIRST?"
Disp "1-YES,2-NO"
Input [B](5,2
If 3<[B](5,2
Goto H
DispGraph
Pause
1»X
If 2=[B](5,2
2»X
Goto S
Lbl X
DispGraph
Pause
1»X
Lbl S
0»[B](4,3
Lbl A
0»ˆ
0»M
0»N
ClrHome
If (X=2)([B](4,2)=1
Goto R
If X=1
Disp "PLAYER 1"
If (X=2)([B](4,2)=2
Disp "PLAYER 2"
Lbl C
DispHome
Input ˆ
Lbl U
0»Y
If ˆ=1
Goto 1
If ˆ=2
Goto 2
If ˆ=3
Goto 3
If ˆ=4
Goto 4
If ˆ=5
Goto 5
If ˆ=6
Goto 6
If ˆ=7
Goto 7
If ˆ=8
Goto 8
If ˆ=9
Goto 9
Lbl 1
o»ˆ
1»M
1»N
Goto 0
Lbl 2
1»M
2»N
0»ˆ
.42»Y
Goto 0
Lbl 3
1»M
3»N
.86»Y
0»ˆ
Goto 0
Lbl 4
2»M
1»N
ª.43»ˆ
Goto 0
Lbl 5
2»M
2»N
.42»Y
ª.43»ˆ
Goto 0
Lbl 6
2»M
3»N
.86»Y
ª.43»ˆ
Goto 0
Lbl 7
3»M
1»N
ª.87»ˆ
Goto 0
Lbl 8
3»M
2»N
.42»Y
ª.87»ˆ
Goto 0
Lbl 9
3»M
3»N
.86»Y
ª.87»ˆ
Lbl 0
If 1=[B](M,N
Goto A
1»[B](M,N
3»[A](M,N
If X=2
ª3»[A](M,N
Lbl Z
Y+[C](1,1»A
ˆ+[C](1,2»B
Y+[C](1,3»C
ˆ+[C](1,4»D
Y+[C](1,5»I
ˆ+[C](1,6»J
ˆ+[C](2,1»L
Y+[C](2,2»O
If X=2
Goto Y
Line(A,B,C,D
Line(C,B,A,D
2»X
Goto K
Lbl Y
Line(I,J,I,L
Line(I,L,O,L
Line(O,L,O,J
Line(O,J,I,J
1»X
Lbl K
Pause
Prgm3
If ˆ=5
End
Goto S
Lbl R
6»Y
Goto Q
Lbl W
ª6»Y
Lbl Q
If 0=[B](2,2
5»ˆ
If 0=[B](1,1
1»ˆ
[A](1,1»A
[A](1,2»B
[A](1,3»C
[A](2,1»D
[A](2,2»E
[A](2,3»F
[A](3,1»G
[A](3,2»H
[A](3,3»I
If A+D+G=Y
Goto B
IF B+E+H=Y
Goto D
If C+F+I=Y
Goto E
If A+B+C=Y
Goto F
If D+E+F=Y
Goto I
If G+H+I=Y
Goto J
If A+E+I=Y
Goto L
If C+E+G=Y
Goto M
Lbl P
If Y=6
Goto W
If ˆ�0
Goto U
Lbl V
IPart(Rand(10»ˆ
If ˆ=0
Goto V
Goto U
Lbl B
If A+D=Y
7»ˆ
If A+G=Y
4»ˆ
If D+G=Y
1»ˆ
Goto P
Lbl D
If B+E=Y
8»ˆ
If B+H=Y
5»ˆ
If E+H=Y
2»ˆ
Goto P
Lbl E
If C+F=Y
9»ˆ
If C+I=Y
6»ˆ
If F+I=Y
3»ˆ
Goto P
Lbl F
If A+B=Y
3»ˆ
IF A+C=Y
2»ˆ
IF B+C=Y
1»ˆ
Goto P
Lbl I
If D+E=Y
6»ˆ
If D+F=Y
5»ˆ
If E+F=Y
4»ˆ
Goto P
Lbl J
If G+H=Y
9»ˆ
If G+I=Y
8»ˆ
If H+I=Y
7»ˆ
Goto P
Lbl L
If A+E=Y
9»ˆ
If A+I=Y
5»ˆ
If E+I=Y
1»ˆ
Goto P
Lbl M
If C+E=Y
7»ˆ
If C+G=Y
5»ˆ
If E+G=Y
3»ˆ
Goto P


Prgm3:WIN
0»ˆ
[A](1,1»A
[A](1,2»B
[A](1,3»C
[A](2,1»D
[A](2,2»E
[A](2,3»F
[A](3,1»G
[A](3,2»H
[A](3,3»I
ª9»Y
Goto 6
Lbl 5
9»Y
Lbl 6
If A+D+G=Y
Goto 4
If B+E+H=Y
Goto 4
If C+F+I=Y
Goto 4
If A+B+C=Y
Goto 4
If D+E+F=Y
Goto 4
If G+H+I=Y
Goto 4
If A+E+I=Y
Goto 4
If C+E+G=Y
Goto 4
If Y=ª9
Goto 5
If 9=[B](1,1)+[B](1,2)+[B](1,3)+[B](2,1)+[B](2,2)+[B](2,3)+[B](3,1)+[B](3,2)+[B](3,3
Goto 3
End
Lbl 1
ClrHome
If 2=[B](4,2
Disp "PLAYER 1 WINS!"
If 1=[B](4,2
Disp "YOU WIN!"
Goto R
Lbl 2
ClrHome
If 1=[B](4,2
Disp "I WIN!"
If 2=[B](4,2
Disp "PLAYER 2 WINS!"
Lbl R
5»ˆ
Pause
End
Lbl 3
ClrHome
Disp "CAT!"
Goto R
Lbl 4
If Y=9
Goto 1
If Y=ª9
Goto 2



Note:This program uses all of the TI-81's matices.  The following numbers must be put into matrix [C] for the program to run:

1,1:1.5460526
1,2:2.9861111
1,3:1.2039474
1,4:3.3034524
1,5:1.5065789
1,6:3.0059524
2,1:3.3035714
2,2:1.2565789
2,3:1.5732684
2,4:3.3630952
2,5:1.5723684
2,6:2.1130952
3,1:2.0197368
3,2:2.1130952
3,3:2.0197368
3,4:3.3630952
3,5:2.4407895
3,6:2.9465286
4,1:1.1907895
4,2:2.9465286
4,3:1.1907895
4,4:2.5099206
4,5:2.4407895
4,6:2.5099206
5,1:1.190789474
5,2:2.440789474
5,3:2.113095238
5,4:3.363095238