local function status(msg)
  if gpu and screen then
    gpu.set(1, y, msg)
    if y == h then
      gpu.copy(1, 2, w, h - 1, 0, -1)
      gpu.fill(1, h, w, 1, " ")
    else
      y = y + 1
    end
  end
  -- boot can be slow in some environments, protect from timeouts
  if uptime() - last_sleep > 1 then
    local signal = table.pack(pull(0))
    -- there might not be any signal
    if signal.n > 0 then
      -- push the signal back in queue for the system to use it
      computer.pushSignal(table.unpack(signal, 1, signal.n))
    end
    last_sleep = uptime()
  end
end