Chute dispenser EEPROM

-- Blueshop item chute controller
-- TX = 0, RX = (Number of items)
-- TX = (Number of items), RX = (0 if OK, 1 if stock too low)
local network = component.proxy(component.list("modem")())
local redstone = component.proxy(component.list("redstone")())

local strength = 255 -- 255 if using Project:Red, 15 if using Vanilla
local stackSize = 64 -- How many items per stack, used by stock calculation
local stock

network.open(120) -- Ensure that the network card is open on chute port (120)
redstone.setOutput(0, 0) -- Set a known state for the dispenser output
network.broadcast(120, network.address) -- Broadcast address for master unit

-- "modem_message" _ reply _ _ msg
while true do
  local signal = table.pack(computer.pullSignal())
  if signal[1] == "modem_message" then -- New message over network
    if signal[6] == 0 then -- Request system stock
      network.send(signal[3], 120, checkStock())
    elseif signal[6] <= stock then -- Request dispenser fire
      for i = 1,signal[6],1 do
        computer.pullSignal(0.1) -- Avoid system timeout errors
        redstone.setOutput(0, strength) -- Best case 50% MSR, worst case 33% MSR
        os.sleep(0.1)
        redstone.setOutput(0, 0)
        os.sleep(0.1)
      end
      network.send(signal[3], 120, 0)
    else
      network.send(signal[3], 120, -1)
    end
  end
end

local function checkStock() -- Returns integer, containing lower-bound stock
  local strength = redstone.getInput(4)
  stock = math.ceil((stackSize * 54 / 14) * (strength - 1))
  return max(strength, stock)
end