penup! () 
goto! (150, 150) & should be (-150, -150)
right! (0.25)

let root_2 = 1.414213562
let cell_size = 15
let line_length = mult (root_2, cell_size)

fn upstroke! () -> {
  print! (:up)
  penup! ()
  forward! (cell_size)
  left! (0.125)
  pendown! ()
  back! (line_length)
  penup! ()
  forward! (line_length)
  right! (0.125)
}

fn downstroke! () -> {
  print! (:down)
  pendown! ()
  right! (0.125)
  forward! (line_length)
  left! (0.375)
  penup! ()
  forward! (cell_size)
  right! (0.25)
}

fn up_or_down! () -> {
  let rand = random ()
  if lt? (rand, 0.5)
    then upstroke! ()
    else downstroke! ()
}

fn newline! () -> {
  penup! ()
  back! (mult (grid_size, cell_size))
  right! (0.25)
  forward! (cell_size)
  left! (0.25)
}

let grid_size = 20

fn randcolor! () -> pencolor! ((random (0, 255), random (0, 255), random (0, 255)))



  repeat grid_size {
    randcolor! ()
    up_or_down! ()
  }

& repeat grid_size { 

&   newline! ()
& }