Connect Mac Mini M1 to M1 iMac

Are you using Target Display Mode on your 2011 Mini?

Nope. In the Intel mini's System Preferences > Sharing panel, there is checkbox for Screen Sharing. That is Apple's built-in Virtual Network Computing (VNC) functionality, and by using screen sharing, I use Apple's Screen Sharing Application (/System/Library/CoreServices/Applications) that I have dropped on my Dock, and about time enough for the mini to boot up, I enter hostname.local in the Screen Sharing application's dialog. When done, I shutdown the Intel mini as I would normally in the window on my M1 mini, reach up to the Screen Sharing app's Connection menu and click Close, and then quit the app.

I have two-way drag and drop, and clipboards between the two Macs using the Screen Sharing app. It is wise to do this over Ethernet, or WiFi 6 for improved bandwidth.

See Share the screen of another Mac - Apple Support

Sharing > Screen Sharing is selected on the Intel mini, but not on the Macs where I want to view it.

I disable Block all incoming connections on the Intel mini, but leave those enabled on the recipient Mac's Firewall settings. Since this is a home network that is locked down, so there won't be any unvited guests.

The following is on the recipient Mac via the Screen Sharing application:

The 2011 mini's display takes up about 3/4 of the 27-in 2020 iMac display.

No because new Mac’s do not support Target Display Mode.

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

The cheapest solution is to source a secondhand HD display and use that with a suitable adapter, or even a new HD display for less than £100 GBP ($117). Cables are cheap as are adapters. I’m using one of my old 24” HD displays as a second display for my M1 iMac.

guy224 wrote:

Any experience with the Luna Display device?

The problem would be you would need a display for the Mac Mini so you can install and turn on the display on your iMac in the first place. Otherwise, you couldn't see what you were doing. 😎

One can get HDMI, or DisplayPort dummy display dongles that trick the operating system into believing there is an HDMI display connected, and then one can screen share to other Macs. That is how my 2011 Mac mini with High Sierra works as otherwise, it is headless. I just walk up to it, turn it on and walk away. In the other room, I can use Apple's Screen Sharing app to open that Mac mini display on my M1 minis 32-in display.

You’re welcome.

Most any external displays or even an HDMI TV will work with the Mac mini.

see > Connect a display to Mac mini - Apple Support

Nope’ plus I don’t think Luna Display works the same as connecting an external display directly to the Mac mini.