10 CLV:CLS
20 FOR Y=0 TO 44
30 DRAW 0,Y,62,Y
40 NEXT
60 P=#6FE
70 X=61:Y=1
80 DRAW X,Y,0
90 GSB 200
95 IF R=0 IF P<=#700 GOTO 300 ELSE GSB 700:GOTO 90
97 IF R>1 P=P+2:POKE P,X,Y
100 D=RND(4):R=0
110 GSB 500
120 IF R=0 GOTO 100
130 DRAW X,Y,U,V,0
150 X=U:Y=V
160 'IF !INKEY() CONT
170 GOTO 90
200 R=0:FOR D=0 TO 3
210 GSB 500
220 NEXT
230 RTN
300 X=1:Y=1:CLT
305 DRAW X,Y,0
310 U=X-BTN(28)+BTN(29)
320 V=Y-BTN(30)+BTN(31)
325 DRAW X,Y,1
330 LC 0,23:?TICK()/60;
340 C=POINT(U,V)
350 IF C GOTO 310
360 DRAW X,Y,0
370 X=U:Y=V
380 DRAW X,Y,1
390 WAIT 6
400 IF X!=61 OR Y!=43 GOTO 305
410 LC 0,0:CLK:OK 2
420 END
500 A=0:B=0
510 IF D=0 A=-1
520 IF D=1 A=1
530 IF D=2 B=-1
540 IF D=3 B=1
550 U=X+A*2:V=Y+B*2
560 IF U<0 OR U>62 RTN
570 IF V<0 OR V>44 RTN
580 IF POINT(U,V)=0 RTN
590 R=R+1
600 RTN
700 Q=#700
710 X=PEEK(Q):Y=PEEK(Q+1):GSB 200
720 IF !R COPY Q,Q+2,P-Q:P=P-2:IF Q<P GOTO 710
730 IF Q<P Q=Q+2:GOTO 710
740 Q=#700:B=#FFE&RND(P-Q+2):A=Q+B
750 X=PEEK(A):Y=PEEK(A+1)
760 RTN