10 CLS:SCREEN,0:A=32:M=30
20 FORL=2TO62:PSET(60,L):PSET(120,L):PSET(180,L):NEXTL
30 FORL=1TO239:PSET(L,2):PSET(L,62):NEXTL
40 R=RND(1):S=RND(1):D=NOTD
50 B=INT(R*M):C=INT(S*M):E=30:GOSUB90
60 B=29-B:C=29-C:E=E+60:GOSUB90
70 B=INT(R*R*M):C=INT(S*S*M):E=E+60:GOSUB90
80 B=29-B:C=29-C:E=E+60:GOSUB90:GOTO40
90 X=E+B:Y=A+C:GOSUB140:X=E+C:Y=A+B:GOSUB140
100 X=E-B:Y=A+C:GOSUB140:X=E-C:Y=A+B:GOSUB140
110 X=E+B:Y=A-C:GOSUB140:X=E+C:Y=A-B:GOSUB140
120 X=E-B:Y=A-C:GOSUB140:X=E-C:Y=A-B:GOSUB140
130 RETURN
140 IFX<0ORX>239THENRETURN
150 IFNOTDTHENPSET(X,Y)ELSEPRESET(X,Y)
160 RETURN