10 KEY OFF:CLS:SCREEN 9
20 X=RND(1)*600+1
30 Y=RND(1)*300+1
40 C=RND(1)*15
50 R=RND(1)*RND(1)*RND(1)*300
60 S=RND(1)*RND(1)*R
70 IF S<3 THEN S=3
80 FOR R1=0 TO R STEP S
90 CIRCLE (X,Y),R1,C
100 NEXT R1
110 I$=INKEY$:IF I$="" THEN 20
120 SCREEN 0:KEY ON:CLS