10 FOR I=0 TO 63
 20 FOR J=43 TO 0 STEP -1
 30 LET X=(I-52)/31
 40 LET Y=(J-22)/31
 50 LET XA=0
 60 LET YA=0
 70 LET ITER=0
 80 LET XTEMP=XA*XA-YA*YA+X
 90 LET YA=2*XA*YA+Y
100 LET XA=XTEMP
110 LET ITER=ITER+1
120 IF XA*XA+YA*YA<=4 AND ITER<200 THEN GOTO 80
130 IF ITER=200 THEN PLOT I, J
140 NEXT J
150 NEXT I