   2 .
   4 .
   6 :return ;clear 
   8 print "78(C)CHECKERSleft JOHN COLLINS";gosub 3000
  50 for U=Ato 89;if @(U)<4goto 55;A=U;U=89
  55 next U;for V=1to 8;print V;for U=Ato 89;if @(U)<4goto 910
  60 for X=9to 11step 2;for Q=1to -1step -2;if @(U)=4Q=-1
  70 B=Qmul X;S=U+B;if @(S)=0goto 900
  75 if V>2if @(S)#3goto 900
  80 C=B+B;F=Qmul 20;Z=Vmul 100;J=0;gosub Z;if J=1goto 960
  90 goto 900
 100 if @(U+C)#3return 
 200 if @(S)-2>0return 
 220 if V=1S=U+C;J=1;return 
 230 if @(U-B)#3return 
 240 if @(U-F)>3S=U-B;U=U-F;J=1;return 
 250 if @(U-C)>3S=U-B;U=U-C;J=1;return 
 260 if @(U-B-F)=3S=U-B-F;J=1;return 
 290 return 
 300 if @(S-F)#1return 
 310 if @(S)=3J=1;return 
 320 if @(S-2mul (X-10))=3S=S-2mul (X-10);J=1
 330 return 
 400 if @(U+C)=0if @(U)=4J=1
 410 return 
 500 if @(U+C)<3return 
 510 if @(U+F)<3if @(U+C-F)=3return 
 520 if @(U+C-F)=1if @(U+F)=3return 
 530 goto 700
 600 L=1;if @(U+C)-3<0return 
 610 if @(U+F)-3<0if @(U+C-F)=3return 
 620 if @(U+F)=3if @(U+C-F)=1return 
 630 L=L+1;D=@(U+Lmul B);if D=0return 
 640 if D-3>0return 
 650 if L#2if D-3<0J=1;return 
 660 goto 630
 700 if @(U)=5return 
 800 J=1;return 
 900 next Q;next X
 910 next U;next V
 920 BC=8;gosub 2000;print "YOU WIN";A=KP;goto 8
 960 R=U;Q=-1;next Q;X=11;next X
 970 V=8;U=89;next U;next V;T=-1;goto 1200
1000 print #1,R,"right ",S;input " FROM"R;if S<A A=S
1010 if @(R)>2goto 1000
1020 if @(R)=0goto 1000
1030 input " TO"S;if @(S)#3goto 1000
1040 if @(R)#1if R>Sgoto 1000
1200 if ((S-R)mul (S-R))<122goto 1600
1210 if T>0if @((S+R)div 2)<4goto 1000
1220 J=T;@(S)=@(R);@((S+R)div 2)=3;@(R)=3
1400 for X=9to 11step 2
1410 if @(S+Jmul X)=3+Tgoto 1450
1420 if @(S+Jmul X)=3+T+Tgoto 1450
1430 goto 1500
1450 if @(S+2mul Jmul X)#3goto 1500
1470 X=11;next X;goto 1220
1500 next X;if (ABS(@(S)-3))=2if J=T J=-T;goto 1400
1510 goto 1610
1600 @(S)=@(R);@(R)=3
1610 if T>0if S>80@(S)=1
1620 if T<0if S<20@(S)=5
1630 if T>0goto 50
1640 T=1;gosub 2000;goto 1000
2000 clear ;box 25,0,96,86,3
2010 for I=12to 89;if @(I)=0goto 2100
2020 M=-25+(I-(Idiv 10)mul 10)mul 10
2030 N=-45+(Idiv 10)mul 10
2040 CX=M-12;CY=N;print #2,I
2050 if @(I)#3box M,N,7,2,1
2060 if @(I)>3box M,N,2,2,3
2070 if ABS(@(I)-3)=2box M,N,7,4,3
2100 next I;return 
3000 for I=1to 100;@(I)=0;next I;for I=12to 18step 2
3010 @(I)=2;@(I+11)=2;@(I+20)=2;@(I+31)=3;@(I+40)=3
3020 @(I+51)=4;@(I+60)=4;@(I+71)=4;next I;A=67
3030 BC=7;FC=146;return 
:return ;run 
