10 SCREEN 5
20 FOR M=0 TO 3:SET PAGE M,M:CLS:NEXT
30 FOR K=0 TO 160 STEP 10:FOR Q=0 TO 5
50 SET PAGE 0,0:CIRCLE(127,106),K+Q,15
60 SET PAGE 1,1:CIRCLE(127,106),K+Q+2,15
70 SET PAGE 2,2:CIRCLE(127,106),K+Q+5,15
80 SET PAGE 3,3:CIRCLE(127,106),K+Q+7,15
90 NEXT:NEXT
100 FOR K=0 TO 3:SET PAGE K,K:NEXT:GOTO 100