Coroutine Testing Center

local slowWrite
local coDone = false
function resetWrite()
slowWrite = coroutine.create(function (str, speed, delay)
  for i = 1, #str do
    local index = 1
    if not coDone then
      write(str:sub(i, i))
      coroutine.yield(1/speed)
    end
  end
  return true, delay
end)
end

function blink(speed)
        if not speed then
                speed = .4
        end
        local a,b = term.getCursorPos()
        uWords(" ", a, b, _, colors.lime)
        coroutine.yield(speed)
        uWords(" ", a, b, _, colors.black)
        coroutine.yield(speed)
    term.setCursorPos(a,b)
end

local messages = {
{"WELCOME TO ROBCO INDUSTRIES (TM) TERMLINK", 160, 1},
{"SET TERMINAL/INQUIRE", 30, .75},
{"\nRIT-V300", 30, 1},
{"\nSET FILE/PROTECTION-OWNER:RWED ACCOUNTS.F", 30, 1},
{"SET HALT RESTART/MAINT", 30, .5},
{"\nInitializing Robco Industries(TM) MF Boot Agent", 160, .1},
{"RETROS BIOS", 160, .1},
{"RBIOS-4.02.08.00 52EE5.E7.E8", 160, .1},
{"Copyright 2201-2201 Robco Ind.", 160, .1},
{"Uppermem: 64 KB", 160, .1},
{"Root (5AB)", 160, .1},
{"Maintenance Mode", 160, 1},
{"\nRUN DEBUG/ACCOUNTS.F", 30, 1}
}

local cMsg = 1
local writeTimer, blinkTimer

function txt()
  term.setCursorBlink(true)
  term.setBackgroundColor(colors.black)
  term.setTextColor(colors.lime)
  term.clear()
  term.setCursorPos(1, 1)
  resetWrite()
  _, length = coroutine.resume(slowWrite, messages[cMsg][1], messages[cMsg][2], messages[cMsg][3])
  writeTimer = os.startTimer(length)
  while true do
    local events = {os.pullEvent()}
    if events[1] == "timer" then
      if events[2] == writeTimer then
        _, length, delay = coroutine.resume(slowWrite, messages[cMsg][1], messages[cMsg][2], messages[cMsg][3])
        if delay then
          writeTimer = os.startTimer(delay)
          cMsg = cMsg + 1
          if cMsg > #messages then
            sleep(delay)
            break
          end
          resetWrite()
          print()
        else
          writeTimer = os.startTimer(length)
        end
      end
    elseif events[1] == "key" or events[1] == "mouse_click" then
      os.cancelTimer(writeTimer)
      coDone = true
      term.setBackgroundColor(colors.black)
      term.clear()
      term.setCursorPos(1, 1)
      break
    end
  end
end

txt()