Helping with Modem

term.clear()
rednet.open("left")
local monitor = peripheral.wrap("top") --# you should localise variables
monitor.setBackgroundColor(colors.black)
monitor.clear()
monitor.setTextColor(colors.lightBlue)
monitor.setCursorPos(3,1)
monitor.write("Oxygen Central")
monitor.setTextColor(colors.white)
monitor.setCursorPos(1,3)
monitor.write("Main Control")
monitor.setCursorPos(1,4)
monitor.write("Oxygen Module")
monitor.setCursorPos(1,5)
monitor.write("Right Wing")
term.setCursorPos(1,1)
print("OXYGEN SYSTEMS")

--# indentation helps with readability
while true do

  redstone = rs.getInput("right") --# this is a useless line, a problem you also have is it overrides the `redstone` API, lucky you use the `rs` alias
  if rs.getInput("right") == true then --# you don't need to have `== true` here, getInput returns true/false
    monitor.setCursorPos(15,3) --# this could be outside the if statements
    monitor.setBackgroundColor(colors.lime)
    monitor.write("ON ")
    sleep(1) --# this is not needed, and means that you'll most likely miss rednet messages
  end

  if rs.getInput("right") == false then --# this could just be an `else` for the above if statement
    monitor.setCursorPos(15,3)
    monitor.setBackgroundColor(colors.red)
    monitor.write("OFF")
    sleep(1) --# this is not needed, and means that you'll most likely miss rednet messages
  end

  local id, message = rednet.receive()
  if message == "o1" and id == 63 then
    monitor.setCursorPos(15,4)
    monitor.setBackgroundColor(colors.blue)
    monitor.write("ON ")
    sleep(1) --# this is not needed, and means that you'll most likely miss rednet messages
  end

  local id, message = rednet.receive()
  if message == "o1n" and id == 63 then
    monitor.setCursorPos(15,4)
    monitor.setBackgroundColor(colors.red)
    monitor.write("OFF")
    sleep(1) --# this is not needed, and means that you'll most likely miss rednet messages
  end

  local id, message = rednet.receive()
  if message == "o2" and id == 77 then
    monitor.setCursorPos(15,5)
    monitor.setBackgroundColor(colors.lime)
    monitor.write("ON ")
    sleep(1) --# this is not needed, and means that you'll most likely miss rednet messages
  end

  local id, message = rednet.receive()
  if message == "o2n" and id == 77 then
    monitor.setCursorPos(15,5)
    monitor.setBackgroundColor(colors.orange)
    monitor.write("OFF")
    sleep(1) --# this is not needed, and means that you'll most likely miss rednet messages
  end
end 

--# lets clear the main terminal and print output now, as we'll be redirecting the terminal shortly
term.clear()
term.setCursorPos(1,1)
print("OXYGEN SYSTEMS")

--# lets open the rednet if it's not already open
if not rednet.isOpen("left") then
  rednet.open("left")
end

--# wrap the monitor
local monitor = peripheral.wrap("top")
--# redirect the terminal to the monitor, that means any calls to `term.` now go to the monitor
term.redirect(monitor)
--# now `write` and `print` also work on monitors, meaning we can use things such as `\n`
term.setBackgroundColor(colors.black)
term.clear()
term.setTextColor(colors.lightBlue)
term.setCursorPos(3,1)
write("Oxygen Central")
term.setTextColor(colors.white)
--# each title will be written at the start of a new line because of the `\n`
term.setCursorPos(1,3)
write("Main Control   OFF\nOxygen Module  OFF\nRight Wing     OFF")

--# writing whether the redstone signal is on or off is extremely similar code
--# so lets make it a function so we do less typing. we provide this function
--# the state of the redstone and the y position that it should be drawn
local function drawState(state, yPos)
  term.setCursorPos(15, yPos)
  --# if the redstone signal is on, set the colour to lime, otherwise set it to red
  term.setBackgroundColor(state and colors.lime or colors.red)
  --# if the redstone signal is on, write 'ON ', otherwise write 'OFF'
  write(state and "ON " or "OFF")
end

while true do
  --# wait here until an event occurs on the computer these can be found here
  --# http://computercraft.info/wiki/Os.pullEvent#Event_types
  local event, senderId, message = os.pullEvent()

  --# if the event was a redstone event it means there has been a change in
  --# redstone around this computer
  if event[1] == "redstone" then
    --# is the signal on?
    local on = rs.getInput("right")
    --# update room one's output
    drawState(on, 3)

  --# if the event was a rednet message it means a computer sent out a message
  elseif event[1] == "rednet_message" then
    --# if the message came from the room two computer
    if senderId == 63 then
      --# was the message that it was on?
      local on = message == "o1"
      --# update room two's output
      drawState(on, 4)

    --# if the message came from the room three computer
    elseif senderId == 77 then
      --# was the message that it was on?
      local on = message == "o2"
      --# update room three's output
      drawState(on, 5)
    end
  end
end