Text defilant

mon = peripheral.wrap("back")
mon.setTextScale(4)
text = "Mars launch: 20s"
pos = 20
while true do
mon.clear()
mon.setCursorPos(pos, 1)
mon.write(text)
sleep(0.2)
if pos == -21 then
pos = 20
else
pos = pos - 1
end
end