Is there any way at all that I can use my 21" iMac as a display for my Xbox 360?!?

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It was possible in Late 2009 and Mid 2010 27-inch iMacs because of Mini DisplayPort and with the use of a special adapter, but this is not possible in new Macs. You can only use your Mac as a display for other Macs with Thunderbolt. The only solution is to get a monitor to connect your Xbox to

LT has a 21.5" iMac and that doesn't support Target Display mode at all regardless of the generation of iMac he has.

Regards.

Thunderbolt iMacs, including 21'5-inch iMacs, support Target Display Mode

Target Display Mode was not supported in 2009 or 2010 21.5-inch iMacs, but it is supported in 2011-2012 21.5-inch iMacs. http://support.apple.com/kb/HT3924

Of course, it doesn't matter either way in this case as it still will not work with an XBox 360.

Brandon2184 wrote:

Target Display Mode was not supported in 2009 or 2010 21.5-inch iMacs, but it is supported in 2011-2012 21.5-inch iMacs. http://support.apple.com/kb/HT3924

Just what I said. Mid 2011 and Late 2012 iMacs are the iMacs with Thunderbolt

My mistake. I clearly misread somewhere. Apologies.

Everybody make mistakes ;-)