@Aslanmane Thanks for the link, but I had checked there and it gave no option for the F1 etc. keys. But I figured it out ...
@zudn @Aslanmane Yeah, Fn is usually part of the #keyboard itself — most keyboards (Mac computers are an exception) can't even tell the computer when Fn is pressed. Fn is just for having more "keys" than physical buttons on the keyboard.
Note that many full-size keyboards do not need an Fn key.
@golemwire @Aslanmane There's a funny function here, the FnLock, and I apparently had punched it. When I noticed it, it was easy enough to undo.