CC: tofu6

-- tofu6
--  surround four directions with walls
turtle.select(1) -- the usual phrase

turtle.up()  -- move up

-- stack six squares
for ronoji=1,6 do
  -- 1st stage is made with slot 1, 2nd stage is slot 2, ...
  turtle.select(ronoji)

  -- make 4 sides of a square
  for hen=1,4 do
    -- -- put 4 blocks in the ground
    for i=1,4 do
      turtle.forward()  -- move to next position
      turtle.placeDown()  -- put a block
    end

    turtle.turnRight()  -- turn 90 degrees to the right
  end

  turtle.up()  -- move up
end