4 Replies Latest reply: Dec 23, 2012 7:31 AM by Dieter45
Dieter45 Level 1 (0 points)

I have bought a new iMac 27" and wouldlike to use myold iMac 27" as a 2. monitor. Can I do this with an Etherent cable?

Thanks for help..

iMac, OS X Mountain Lion (10.8.2)
  • LousyFool Level 4 (2,645 points)

    Not per Ethernet.


    The magic words are "Target Display Mode". The rest depends on which exact model your old iMac is. Some examples:

    - Here for slightly older iMacs.

    - Here and here for younger iMacs.

  • Dieter45 Level 1 (0 points)



    my old iMac 27" is late 2009 and has a Mini Display Port but my new one has none (but USB 3.0 and Thunderbolt).

    I am using the Mini Display Port of the old one already for my TV to play my videos directly there.


    I assume, that I have to get an adapter (which one? via Thunderbolt?)) for my new Mac to connect with my old one. Furthermore, because I want to keep my Mini Display Port from the old Mac for the TV connection, is there an adapter to plug in 2 or more Mini Display Ports?


    Best would be, if I can connect from my new Mac to both, the TV and the old Mac ??


    Thanks for your help

  • James_R_ Level 1 (75 points)

    Thunderbolt has minidsplayport functionality in it.


    Purchase a Mini Displayport to Mini displayport Cable and plug 1 end into a thunderbolt port of your new iMac and the other end into the Mini Displayport of your old Mac.


    Then put your old iMac into target display mode using these methods:


    - Here for slightly older iMacs.

    - Here and here for younger iMacs.




    And it is as simple as that.


    If you still want to use your TV as another screen, plug the minidsplay port->HDMI cable into the other thunderbolt connection of your new iMac.


    You might want to get a thunderbolt hub, since you will be using both ports on your new iMac this way.

  • Dieter45 Level 1 (0 points)

    Thank you, super!