IMac – Use early 2009 20″ iMac as external display for 2015 rMBP

displayimacmacbook prothunderbolt

I wanted to use a mini display-port cable then use "target display mode" to make the iMac an external display, but I just read that early 2009 iMac's don't have target display mode as a feature.

Anybody knows of a solution?

Best Answer

This cannot be done with your particular iMac (2009 20")

Per the Target Display Mode System Requirements Page it specifically says:

A supported iMac with OS X v10.6.1 or later.

The supported iMacs are:

  • iMac (27-inch Late 2009)
  • iMac (27-inch Mid 2010)
  • iMac (Mid 2011)
  • iMac (Mid 2012-Mid 2014)

However, there is an App that allows you to turn a spare Mac into an extended monitor. It's called Air Display. This is not my ideal solution as video intensive applications don't perform well with software solutions.

If you need a secondary monitor, you may have to get a dedicated monitor to meet your needs