Using old mac to create dual display

[themommabaker]

Hello Everyone! I purchased a New Mac in December 2019. According to the specifications I have Thunderbolt 3 digital output and 3 x USB3 ports. I am hoping to connect my old mac mid 2010 with mini display port to use as a dual monitor. HELP! Not the most techno savvy and am confused by the adapters/docks/cables it says I need. When I purchased the new mac I was told that I would have the capability once connected using Target display mode command f2. If anyone can tell me exactly what i need to purchase (adapter? dock? which cables?) I would soooooo greatly appreciate it!! With the COVID outbreak I am now working from home and have dual monitor capability would really make my life easier. THANK YOU

 

[MightyGem]

Which model is your "old mac"?

 

[themommabaker]

It is an iMac 21.5 inch mid 2010

 

[MightyGem]

Thanks. Have you seen this? Says that only the 27" mid 2010 model can be used.

Mac User Guide

Learn what’s new in macOS, how to get started with your Mac and use it with your Apple devices, and how to control privacy and security on macOS.

support.apple.com

 

[themommabaker]

Thanks but when I search Amazon I am not seeing such a cable?? I would need a thunderbolt to mini display port if I am reading correctly...sorry this is so confusion

 

[MightyGem]

I don't think you have read my post or the link correctly. The link says that only the 27" mid 2010 iMac can be used in Target Disk Mode. You say you have the 21" model.

 

[themommabaker]

Darn, I guess I can't use it... Thank you for all your help! I really appreciate your taking so much time to help me.

 

[MightyGem]

That's ok.