I have an iMac 21.5 display Processor 3.06 GHz Intel Core i3 Memory 4 GB 1333 MHz DDR3 and I want to play my Xbox360 through a Mini DisplayPort Converter, but the advertising is for a 27 inch iMac models only. I have a mini port for an external screen but I don't want to purchase one if it wont work. Can you help me with an answer please.