Target Display Mode for 2nd 2012 iMac

[Aspen]

I've searched, youtube'd, etc. and just can't find this precise answer. Any help is greatly appreciated.

Have 2 2012 iMacs, would like to used one in Target Display Mode as a 2nd monitor with Thunderbolt cable.

So after Command f2 to complete the TDM transition to the 2nd iMac ("monitor"), using it for a while then shutting down the computer, does something have to be pressed on the keyboard (keyboard stroke) each and every time the main computer is turned on. And does this require two keyboards each time, one to the computer and the other to the "monitor"? Or is it as simple and turning on the "computer" on both the computer and "monitor" open up identical to the last time it was used?

 

[CoastalOR]

I've searched, youtube'd, etc. and just can't find this precise answer. Any help is greatly appreciated.

Have 2 2012 iMacs, would like to used one in Target Display Mode as a 2nd monitor with Thunderbolt cable.

So after Command f2 to complete the TDM transition to the 2nd iMac ("monitor"), using it for a while then shutting down the computer, does something have to be pressed on the keyboard (keyboard stroke) each and every time the main computer is turned on. And does this require two keyboards each time, one to the computer and the other to the "monitor"? Or is it as simple and turning on the "computer" on both the computer and "monitor" open up identical to the last time it was used?

Just in case you haven't reviewed the Apple instructions recently:
https://support.apple.com/en-us/HT204592

You will need a keyboard connected to the monitor iMac to press Command f2 each time you want to enter TDM. Every time you restart the main computer you will have to enter Command f2 on the monitor iMac keyboard to re-establish TDM. They will not automatically reconnect to TDM on restart. Command f2 will toggle TDM off and on the monitor iMac. Shutting down either computer will exit TDM.