ComputerCraft Scrolling Text (Refined)

--Settings
mon = peripheral.wrap("back") --Screen Side
mon.setTextScale(4)           --Text Size
strtpos = 18                  --Start position on screen
speed = 0.2                   --Scroll Speed (Seconds)
text = "This is some Text"    --Displayed Text

pos = strtpos
poslimit = string.len(text)

while true do
 mon.clear()
 mon.setCursorPos(pos, 1)
 mon.write(text)
 sleep(speed)
 if pos*-1 >= poslimit then
  pos = strtpos
 else
  pos = pos - 1
 end
end