Can I use an older mac (2007) desktop as a monitor for my new MacBook?
Just got a MacBook Pro 13 Retina laptop. Is it possible to use my old Mac desktop (mid 2007) as a monitor for the laptop?
MacBook Pro with Retina display
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You can't use it as an external screen by connecting it to the new MacBook Pro with a cable because Target Display mode is only supported in iMacs.
However, you can use an application like ScreenRecycler to use the old Mac as an external display by using the network