Int 21 Fn 65 - Dos 4.0+ - Country-dependent Character Capitalization [D]

AH = 65h
AL = function
20h capitalize character
DL = character to capitalize

Return: DL = capitalized character
21h capitalize string
DS:DX -> string to capitalize
CX = length of string
22h capitalize ASCIZ string
DS:DX -> ASCIZ string to capitalize

Return: CF set on error
AX = error code (see #1366 at AH=59h/BX=0000h)
CF clear if successful

Note: these calls have been documented for DOS 5+, but were undocumented in
DOS 4.x.
BUG: Novell DOS 7 Update 15 crashes on AX=6521h when CX=0000h