I download games from The Vault and play them on my iMac.
(macOS is required for these instructions.)
Download the mupen64plus emulator and install it in your Applications folder.
The emulator cannot be opened by double-clicking on it. It does not have an interface.
To fix this, download my mupen64plus-launcher.scpt, export it as an app into your Applications folder and set that app as the default handler for .z64 files.
Now, .z64 files will open in the emulator.
If you buy the USB N64 controller, you will have to set it up.
I use the Dolphin emulator.
It is no longer possible to connect Wiimotes with a Mac's internal bluetooth.
You can instead :
Before closing a game, hold the red Power button on the Wiimote to turn it off. (Otherwise, you may have trouble closing the game without force-quitting Dolphin)
To reconnect the Wiimote, start the game and press 1+2 on the Wiimote. It should connect.
You will also need a USB or battery-powered IR emitter bar. It has IR LEDs that the Wiimote's IR camera can see. It does not otherwise connect to anything.
You have two choices : use a generic GameCube-shaped USB controller or use a real GameCube controller with an adapter.
If using a generic USB controller :
If using a real controller :
I use the Visual Boy Advance emulator.
It works out of the box with my GameCube-shaped USB controller.
I use the Nestopia emulator.
To use my USB controller, I had to install Emulator Enhancer (copy the folder to /Library/Application Support/Emulator Enhancer/).
Once Emulator Enhancer is installed, you may now go into the Input tab of Nestopia's Settings window and setup your controller key by key.