Quick-fire questions
Why can’t my iMac 2019 use iPhone Mirroring?
> Sequoia’s iPhone Mirroring is one of its most attractive features, but relies on hardware device attestation to pair that Mac with the iPhone, only possible using an Intel Mac with a T2 chip, or an Apple silicon Mac. As the iMac 2019 doesn’t have the necessary hardware, it can’t pair.
How long does Apple support versions of macOS for?
> Although it has never published this, Apple provides full support for the current version of macOS for the full year.
After that it provides only security fixes for the following two years.
Those aren’t as comprehensive as fixes supplied for the current macOS, though. Once those three years have passed, it’s left unsupported.
How to uninstall a system extension?
> System extensions are replacing kernel extensions, and are a great improvement as they’re far less likely to result in kernel panics. They can only be installed and removed by the app that uses them, and it should have a menu command or control to do that.
How to hide a folder or file?
> This isn’t possible in the Finder unless you first show all hidden items by pressing Cmd+Shift+[.]. Select the item’s name, then prefix it with a period/ stop and press Return. You’ll be prompted to confirm you want to hide it. Cmd+Shift+[.] is three keys together: Cmd, Shift, and the ‘.’ (full stop/period key).