My iMac is 27" late 2012 and was maxed out at OSX 10.15 Catalina.
Some stuff, like MS Teams (to replace Skype that they are killing) would not install as it was too old.
So, I tried this update using OpenCore Legacy Patcher.
I thought going all the way may not be the best so I just updated to OSX 12 Monterey. But then Teams needs OSX 13 min!!!!
Ok, so I did a software update from OSX 12 itself and it updated the Mac to OSX 15.4.1 Sequoia.
All was ok after the OpenCore Legacy Patcher fixed the drivers.
Cura did not work so the latest version fixed that.
The only problem I now have is Arduino 2.3.6 will not start and that looks to be a common problem. I have not found a fix so have gone back to 1.8.19 version.
Here it is now
I have made up USB installers for my other Macs.
Some stuff, like MS Teams (to replace Skype that they are killing) would not install as it was too old.
So, I tried this update using OpenCore Legacy Patcher.
Ok, so I did a software update from OSX 12 itself and it updated the Mac to OSX 15.4.1 Sequoia.
All was ok after the OpenCore Legacy Patcher fixed the drivers.
Cura did not work so the latest version fixed that.
The only problem I now have is Arduino 2.3.6 will not start and that looks to be a common problem. I have not found a fix so have gone back to 1.8.19 version.
Here it is now
I have made up USB installers for my other Macs.