SET MODE "graphics"

OPEN #1: SCREEN 0,1,0,.5

SET WINDOW 0,1,0,1

PLOT 0,0;1,0;1,1;0,1;0,0

OPEN #2: SCREEN 0,1,.5,1

SET WINDOW 0,1,0,1

PLOT 0,0;1,0;1,1;0,1;0,0

!

LET x=0.3

DO WHILE n<=1

LET q=rnd

LET x=4*x*(1-x)

LET n = n + .005

!

WINDOW #1

PLOT n,q;

WINDOW #2

PLOT n,x;

!

LOOP

!

END

!