10 LET o=NOT PI: PAPER o: BORDER o: CLS : LET x=o: LET y=INT PI: LET u=SGN PI: LET v=SGN PI: LET s=y+y: LET l=s*y: LET h=l+s
18 LET x=x+u: LET c=x>o AND x<h: LET r=x>=h: LET x=x*c+h*r: LET u=u*(c-r-(x<=o)): LET y=y+v: LET c=y>o AND y<l: LET r=y>=l: LET y=y*c+l*r: LET v=v*(c-r-(y<=o)): INK s*RND+SGN PI: PRINT AT y+PI,x+s;"*" AND x<=l: GO TO l
