Late 2013 iMac use as 2nd Monitor

[plaver]

Hi Everyone, I have quick question, can a late 2013 iMac running macOS Catalina be used as 2nd monitor connected to 2020 spec iMac. Thanks

 

[iamsludge]

You could use Luna Display - I use a 2014 5k retina iMac as a monitor for an M1 Mini and an M1 Max MBP.


2019 for the newer Mac was the cut-off for Target Display Mode, and High Sierra was the OS cut-off for the older (monitor) iMac.