Multiprojector + Mac OS Window Frustration: A Helpful Trick

  • Hello All,

    So I'm in the last days of my residency here in Lausanne, and was going **_mad_** last week when Mac OS kept opening folder windows on the video projector displays -- which in my situation, I can't actually see. I had to have my dramaturg tell me where the cursor was ("go up, go left, etc.") so that I could click the title bar and drag the window onto the main display. Totally frustrating!
    So I wrote this little Applet in AppleScript. It's a bit like the "Gather Windows" button on the Displays Preferences: Run the app, and every Mac OS Window that is not already on the main display will be placed there. What a relief!

  • Thanks heaps for that, already my fave script!

  • Izzy Guru


  • Beta Gold

    Thanks again!!!

  • Mark, that's fantastic!  I've been wishing for the same thing on Windows!



  • great!

    On a similar subject, when having multiple projectors do you guys have trouble with the computer reassigning the main desktop or other screens order to other devices than control monitor according to what was turned on/in what order? It came across as a question during a meeting today, I thought I had dealt with this before, but can't remember how.

  • Thanks in advance of experiencing this problem. Question: Should I run the app as part of my pre-show setup procedure to prevent this from happening?

  • To PacoTheCharm: I myself don't understand the logic by which the outputs are chosen -- but I've ended up with the menu bar on the beamer several times now. Very frustrating! My procedure now goes like this.

    1) Start with only main monitor plugged in. This ensures the login screen and menu bar show up there first.
    2) Plug in each beamer, ensuring that it is done in a reliable order each time (i.e., projector 1, then projector 2, etc.)
    This seems to give me a reliable setup. But maybe someone else has a better solution.
    To Vanderzee: Running it advance won't help. But if you open a window and it ends up on the beamer, run this app and and it will place all windows on the main screen.

  • I had a feeling that the bar on the beamer issue only happens once, when a given projector is connected to a computer for the first time. After that, it seemed to remember the the settings from the previous time.

  • Beta Tester

    Actually, 10.8 has a known bug on Mac Pros wherein it forgets which monitor is primary on restart which could account for some of these issues.

  • Yep, had the very same problems with main monitor being forgotten consistently on a MacPro on OS 10.8 with two video cards and four projectors. Seems to me Apple has been spending too much time thinking about the iPhone... really poor programming behaviour methinks?

  • ps, thanks for the script, mark. WIll try it tomorrow on the MacPro.  :)

  • Thanks, that's super helpful.

    I noticed that it doesn't move over the System Prefs windows. Would it be possible to make the script do that?
    It would be useful in the following scenario: Sometimes I need to change the desktop backgrounds to solid black, however the "Gather Windows" feature only works with the Displays prefs. In a multi-projector setup, it's a huge pain to grab all those Desktop & Screen Saver windows and drag them over.
    PS - A little tip for reducing headaches during tech. When I'm in a multi-projector situation and can't see where my mouse is, I turn on a little app called PinPoint. It puts a big red circle around your mouse pointer and makes it a lot easier to find!

  • fantastic... Thanks!

  • Hi,

    for pc users, a little software that simulates edid, so you system allways "see" monitors even if they are not yet plugged:
    [power strip](
    A little hardware solution for those who can afford it:
    [dvi detective](
  • Beta Tester

    @Dappertutto, Screenblacker which is a free little Mac app from the people behind QLab might be useful to you. It's one of those things that seems a little silly but is super handy.

  • Fantastic!

    On one computer, though, (out of 3 that I put it on), it isn't working and I am getting a message that says "access for assistive devices is disabled". Any idea? The other two it works great.
  • Beta Tester

    Trying going to Accessibility in System Preferences and turning on the check box for assistive devices.

  • Izzy Guru


    Another thing that helps you seeing the cursor, got to Accessiblitiy in System Preferences and change the cursor size to really big. I use that often.


  • @MatthewH: I'm assuming by 'Accessibility' you mean 'Universal Access'. Thank you, but although it was, in fact, disabled, I've enabled it, restarted, and still getting the same error message. It gives me the option of then going in and editing the script but I'm no programmer.