local m = peripheral.wrap("left")

local perc = 0
while true do
  m.clear()
  m.setTextScale(1)
  m.setCursorPos(1,1)
  m.setTextColour(512)
  m.setBackgroundColor(colors.lime)
  for i=1, perc do
    m.write(" ")
  end
  m.setBackgroundColor(colors.black)
  perc = perc + 1
  if perc > 200 then perc = 0 end
end