Use your iMac as a display with target display mode - Apple Support

How to add and use a second monitor with your Mac

Using Late 2009 Imac as external display … - Apple Community

Target Display mode is pretty Universal on the 27 inch iMacs from 2009 & 2010 with only a mini display port connection required. : r/mac

Command F2 not working after upgrade to S… - Apple Community

Getting Target Display Mode to Function on Late 2009 iMac

Luna Display's powerful Target Display Mode feature for Mac adds Ethernet and Thunderbolt support - 9to5Mac

Target display mode - Apple Community

Mac OS Ventura TARGET DISPLAY MODE IS BACK!! Using an old iMac as a monitor OCLP

Use iMac as monitor: 5 Solutions - 9to5Mac

Replacement of iMac Target Display Mode for Apple Silicon with Virtual Display and Screen Sharing

Use ANY Mac as a monitor, not just Target Display!

How to Use External Monitors With Mac Laptops and Desktops

Using an iMac as a Monitor Is More Complicated Than You Might Think

Use your old iMac as a 2nd screen using LUNA Display