Using a late 2009 27" iMac as a second display
I have a late 2009 27" iMac, I will be getting a new 27" iMac, can I use the old iMac as a second display with the new iMac to give an extended desktop.
WIll I need to use a thunderbolt cable?
iMac (27-inch Late 2009), iOS 8.1.2