Int 21 Fn 65 U - Dos 4.0+ Internal - Country-dependent Filename Capitali [D]
AH = 65h
AL = function
A0h capitalize filename character
DL = character to capitalize
Return: DL = capitalized character
A1h capitalize counted filename string
DS:DX -> filename string to capitalize
CX = length of string
A2h capitalize ASCIZ filename
DS:DX -> ASCIZ filename to capitalize
Return: CF set on error
AX = error code (see #1366 at AH=59h/BX=0000h)
CF clear if successful
Note: nonfunctional in MS-DOS 4.00 through 6.00 due to a bug (the code sets a
pointer depending on the high bit of AL, but doesn't clear the
bit before branching by function number). Supported and
functional(!) in Novell DOS 7 (Update 15)