Int 16 Fn FFF2  U - PC Tools V5.1-8.0 Desktop - Display Help Line          [U]

   AX = FFF2h
   DS:SI -> ASCIZ function key label string (each label preceded by '[')
       or help text

Return: AX destroyed

Notes: available only when popped up
   if the specified string does not start with '[', it is displayed
     centered on the bottom line, else the function key labels are shown