TPcom-v2

-- Tp Computer V2

local side=nil
for k,v in pairs(rs.getSides()) do
  if peripheral.getType(v)=='modem' then
   rednet.open(v)
   break
  end
end

function tpRegister()
  rednet.broadcast("tpRegister")
  os.sleep(0.1)
  serv, dud = rednet.receive()
  file = fs.open("serv", "w")
  file.write(serv)
  file:close()
  term.clear()
  term.setCursorPos(1,1)
  term.write("Type the number of this level: ")
  level = read()
  term.clear()
  term.setCursorPos(1,1)
  rednet.send(serv, level)
end

result = fs.exists("serv")
if result == true then
  file = io.open("serv", "r")
  serv = file.read()
  file:close()
  serv = tonumber(serv)
else
  tpRegister()
end
while true do
  x, y = rednet.receive()
  if x == serv and y == "true" then
    rs.setOutput("back", true)
    os.sleep(0.4)
    rs.setOutput("back", false)
  end
end