Use iMac as Second Monitor

[RDubbs]

Good morning,
I am trying to get a iMac (21.5-inch late 2009) connected to a MacBook Pro (Retina, 15-inch, Mid 2014) to use as it's second monitor. The iMac is pretty old. I have bought 4 cables but am not getting connectivity with any combo.

Apple Thunderbolt Cable (2 m)
Apple Mini DisplayPort to VGA Adapter
Apple Mini DisplayPort to DVI Adapter (Single Link)
Apple Mini DisplayPort to Dual-Link DVI Adapter

It's looking like a compatibility issue. Does anyone know about the iMac (21.5-inch late 2009) and the kind of cables that existed that worked with it that would still be compatable with the 2014 MacBook Pro?

It's for my bosses daughter. So replacing the old computer isn't really an option.

 

[Cougarcat]

Doesn't look like it supports that feature: https://support.apple.com/en-us/HT204592

 

[RDubbs]

Thanks Cougarcat. I think you're right.

 

[jerryk]

You can buy a 24" 1080 monitor for $120 or so on Amazon that supports HDMI and DVI connections. For another $30 or so you can get one that has Display Port. I would not spend too much time working on this.

 

[HBOC]

i got a 27" HP from Costco and it was $170. gets amazing reviews on amazon and newegg. the model is 27xw i think.