[hollerith]

>On the Mac there is no setting "bios" or otherwise to remap it though.

That might be literally true for some sense of the word "setting", but its certainly misleading: in the lower levels of OS X, the function key can almost certainly be remapped to control.

The only reason I had to add the qualifier "almost certainly" is that I never had to learn how to use OS X's analog to loadkeys or xmodmap because for my purposes it sufficed for Emacs to swap function with control.

But since Emacs has access to the "raw scancode" for the function key, OS X must have it, too.

In other words, the Mac is not like one of those PC laptops where the interpretation of "the function modifier bit" takes place at a level lower than the OS. Consequently I would be shocked if there were no way to swap function with control OS-wide if one is willing to research the question on the net.