ComputerCraft FTB Infinity Skyblock Server

-- This applicaiton serves as a server for my turtle bots as I make more...
-- I honestly don't intend for other people to use it, I'm just putting it here for myself...
-- But I don't mind others using it, so feel free to take a gander, reuse, reinvent, plagiarize, whatever...
-- The main program for my turtle bots is here:
-- http://pastebin.com/n5cxXaRb

-- Notes:
--       Turtle 1 will be on Port 100
--       Turtle 2 will be on Port 102
--       Turtle 3 will be on Port 103

serverPort = 25565

-- Unknown transmission will be printed cycling incrementally between these lines.
unknownSourceTop = 30
unknownSourceBottom = 40
unknownSourceLine = unknownSourceTop -- Keep track of the current line.

-- Normal Text Color
defaultTextColor = colors.white
-- Normal Screen Color
defaultBackColor = colors.black

-- Keeps track of whether we have already received at least one unknown message.
-- Used to prevent from accidentally printing an orange
-- square where it doesn't belong.
hasReceivedAtLeastOneUnknownMessage = false

-- Prints a message from an unkown source
function PrintMessageFromUnknownSource(message, port, monitor)
  -- Mark the current line.
  monitor.setCursorPos(1, unknownSourceLine)
  monitor.clearLine()
  monitor.blit(" ","d","d")
  -- Write the text from the unknown source
  monitor.setCursorPos(2, unknownSourceLine)
  monitor.write(unknownSourceLine.." - ["..port.."] - "..message)

  if hasReceivedAtLeastOneUnknownMessage then
    -- Clear the previous line's special mark
    if unknownSourceLine == unknownSourceTop then
      monitor.setCursorPos(1, unknownSourceBottom)
      monitor.blit(" ", "1", "1") -- draw an orange box (space)
    else
      monitor.setCursorPos(1, unknownSourceLine - 1)
      monitor.blit(" ", "1", "1") -- draw an orange box (space)
    end
  else
    hasReceivedAtLeastOneUnknownMessage = true
  end


  -- Increment and wrap unknownSourceLine
  unknownSourceLine = unknownSourceLine + 1

  if unknownSourceLine > unknownSourceBottom then
    unknownSourceLine = unknownSourceTop
  end
end

-- Prints a turtle message in it's corresponding location
function printTurtleMessage(message, distance, port, monitor)
  successful = false -- Used to keep track of we found a corresponding turtlebot.

  if port == 100 then
    successful = true
    monitor.setCursorPos(1, 5)
    monitor.clearLine()
    monitor.write("Turtle 1: "..message)
  elseif port == 102 then
    successful = true
    monitor.setCursorPos(1, 6)
    monitor.clearLine()
    monitor.write("Turtle 2: "..message)
  elseif port == 103 then
    successful = true
    monitor.setCursorPos(1, 7)
    monitor.clearLine()
    monitor.write("Turtle 3: "..message)
  elseif port == 104 then
    successful = true
    monitor.setCursorPos(1, 8)
    monitor.clearLine()
    monitor.write("Turtle 4: "..message)
  elseif port == 105 then
    successful = true
    monitor.setCursorPos(1, 9)
    monitor.clearLine()
    monitor.write("Turtle 5: "..message)
  elseif port == 106 then
    successful = true
    monitor.setCursorPos(1, 10)
    monitor.clearLine()
    monitor.write("Turtle 6: "..message)
  elseif port == 107 then
    successful = true
    monitor.setCursorPos(1, 11)
    monitor.clearLine()
    monitor.write("Turtle 7: "..message)
  elseif port == 108 then
    successful = true
    monitor.setCursorPos(1, 12)
    monitor.clearLine()
    monitor.write("Turtle 8: "..message)
  elseif port == 109 then
    successful = true
    monitor.setCursorPos(1, 13)
    monitor.clearLine()
    monitor.write("Turtle 9: "..message)
  elseif port == 110 then
    successful = true
    monitor.setCursorPos(1, 14)
    monitor.clearLine()
    monitor.write("Turtle 10: "..message)
  end

  if not successful then
    PrintMessageFromUnknownSource(message, port, monitor)
  end
end

-- Get a reference to the Modem.
modem = peripheral.wrap("back") -- Put the location of the modem here.

-- Open a channel to listen to on the Modem
modem.open(serverPort)

if modem.isOpen(serverPort)
then
  write("The modem is open.\r\n")
else
  write("The modem is closed.\r\n")
end

-- Get a reference to the Monitor
monitor = peripheral.wrap("top")
monitor.clear()

monitor.setCursorPos(1, 1)
monitor.setTextColor(defaultTextColor)
monitor.write("This computer is listening for incoming transmissions at address: "..serverPort)

while true do
  write("Listening for event\r\n")

  local event, modemSide, senderChannel,
    replyChannel, message, senderDistance = os.pullEvent("modem_message")

  printTurtleMessage(message, senderDistance,
    replyChannel, monitor)

  write("Retrieved an event\r\n")
end

write("Press any key to exit\r\n")
os.pullEvent("key")