19. Lock out lower-case
    ~~~~~~~~~~~~~~~~~~~
On occasions, it can be useful for lower-case letters to be treated the same
as upper-case in GET$ statements, to avoid having to test for "Y" and "y" for
"YES", etc.. This Function will always return upper-case letters, even if the
<Caps Lock> isn't on. It is written as a Function, which you use:

 1000 DEFFNget:=CHR$(GET AND &DF)