M4 mini Mac compatiblity with 2017 MacBooks (Sequoia) and IMac Catalina

The keyboard/mouse (from iMac) will work with Mac Mini - via Bluetooth connection.

However, Using the screen of MacBook Pro - is not possible. You will need stand alone monitor for Mac Mini.

"Target Display" function has been stopped by Apple.

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For what it is worth Target Display Mode has been dead over a decade. If you are interested in reading up about TDM's requirements please read Target Display Mode.

Also, Target Display Mode NEVER worked with Retina iMacs.

Finally, there is a wide variety of external displays that will work with the new Mac Mini's (meaning scores of them) ranging in price <$100 to $1500+. For about $300 you can have a very nice one though.

samtenor wrote:

In my case, I am still hoping "some day" I can repurpose my retired 2 iMac 5K's beautiful screens.

If you have a 27" 5K Retina iMac, you could look into Luna Display (by Astropad) as a means of using that iMac as a second display. You'll still need a real display (e.g., iMac display, Mac notebook display, or hardware monitor) to set up things, and the arrangement won't be as good as a hardware connection to a 27" Apple 5K Studio Display.

Astropad – Luna Display

Astropad – How to Use Your iMac as a Monitor: A Step-by-Step Guide [2024]

"Like any product, Luna Display does have limitations and it’s not recommended for high-motion content. For example, I wouldn’t recommend using Luna Display for gaming or video editing.

Since Luna Display is squeezing a 5K display through a USB cable, when lots of motion occurs on-screen (like from video playback or moving a window quickly) the screen can temporarily become pixelated before it renders in at full resolution."

You are welcome.

We share similar sentiment about our beloved old Macs. In my case, I am still hoping "some day" I can repurpose my retired 2 iMac 5K's beautiful screens.

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