10 S=4
20 T=S*2:INC S
30 FOR Y=-T TO T:AY=ABS(Y)
40 FOR X=-T TO T:AX=ABS(X)
60 IF S>ABS(AY-AX) AND (S>AY OR S>AX) THEN PRINT "*"; ELSE PRINT " ";
70 NEXT X
80 PRINT
90 NEXT Y
100 C=C+1
110 COLOR ((C<<4)+15) AND 255
120 GOTO 100
