Here's my MacBook: http://www.everymac.com/systems/apple/macbook_pro/specs/macbook-pro-core-2-duo-2.53-aluminum-13-mid-2009-sd-firewire-800-unibody-specs.html

Here's the iMac: http://www.everymac.com/systems/apple/imac/specs/imac-core-i5-3.2-27-inch-aluminum-late-2012-specs.html

Basically, my MBP has one Mini DisplayPort and the iMac has multiple thunderbolt ports. These two are the same shape.

Is there an adapter or chord I can use to connect these two so that my MacBook uses the iMac as a secondary monitor?

  • You want to subordinate your 2012 iMac to a 2009 MBP just for the screen space. Really?! Surely you can just sync the filespaces or some better option?
    – John2095
    Sep 19, 2014 at 13:41
  • 2
    Please don't be so rude, friend. For various reasons, yes, I do want that. The MBP is my main work computer for the moment and the iMac belongs to the school I go to. I have software and other things on my MBP that I can't get on the iMac unfortunately. So in those cases it would be hella convenient to just hook up my own computer to the iMac.
    – gburning
    Sep 19, 2014 at 13:50
  • 1
    OK that makes sense. No, not rude—sanity checking.
    – John2095
    Sep 19, 2014 at 14:00

2 Answers 2


As far as I'm aware, you can't run Target Display Mode from Mini DisplayPort to Thunderbolt; only like to like or Thunderbolt to Mini-DP.

See http://support.apple.com/kb/PH14264

Edit 2022
Many years later, we now have a canonical QA for Target Display Mode. Please refer to - What are the requirements to use iMac screen as a second monitor - Target Display Mode?

  • Thanks for the link! From that article: "If you have a 27-inch iMac with a Mini DisplayPort, any other Mac with a Mini DisplayPort or Thunderbolt port can use it as a display. Make sure you have a Mini DisplayPort to Mini DisplayPort cable." Would that work, do you think?
    – gburning
    Sep 19, 2014 at 13:18
  • 1
    From that article, not if the iMac has Thunderbolt, only if it has DisplayPort.
    – Tetsujin
    Sep 19, 2014 at 13:21
  • To be honest, I'm not so convinced. I'll probably buy a cable, try it myself and report back. Thanks for helping, though! You've pointed me in the right direction.
    – gburning
    Sep 19, 2014 at 13:55
  • That table reinforces my existing perception.
    – Tetsujin
    Sep 19, 2014 at 13:57
  • 1
    Bought the cable and tried it out. You were of course correct, it did not work. Thanks for the help though!
    – gburning
    Nov 1, 2014 at 13:52

Screen-sharing may work for you in this instance, if the computers share a network. Note this is not a hardware (cable) solution, but it may work sufficiently well for you.

From the iMac's Finder, locate and click on the MBP's icon from the left window pane. In the title bar of the right pane, click on "Share screen...", authenticate, and begin your work.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .