This morning, I needed to transfer several large files (video files created from Tivo recordings) from my new AS MacBookPro to my 2020 Intel iMac. I decided to do that by attaching the MBP to the iMac using the Thunderbolt 3 cable that came with my CalDigit Thunderbolt hub and attaching the MBP to iMac by starting the MBP in Target Disk Mode. Traditionally that has been done by starting the computer while holding the ‘T’ key down on the keyboard. However, that doesn’t work with an Apple Silicon Mac.
The procedure, discussed for computers running Monterey is described by Apple Support here.
After connecting the computer, you put the AS Mac in Recovery Mode by holding down the power key until startup options are loaded. You then click Options Icon and Continue and then supply a password for an administrator id. Up to this point, this is what you would do for a recovery. Now, however, from the menu bar that has appeared, you click Utilities → Share Disk. The disk(s). Select the one to be shared and click ‘Start Sharing’.
The fun is just beginning. Rather than the shared drive of the AS Mac appearing as an external drive on the other Mac, it appears as a location on the Network either via the Go->Network menu or under the Locations->Network item in the sidebar of a Finder window. Then find the file(s) to be transferred and copy or move them. The speed makes it worth it.