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 qold=rnd

LET xold=0.3

DO WHILE n<=1

LET qnew=rnd

LET xnew=4*xold*(1-xold)

LET n = n + .005

WINDOW #1

PLOT qold,qnew

WINDOW #2

PLOT xold,xnew

LET xold=xnew

LET qold=qnew

LOOP

END