INT 21 - DOS 2+ - "CHMOD" - SET FILE ATTRIBUTES

	AX = 4301h
	CX = new file attributes (see #01420)
	DS:DX -> ASCIZ filename
Return: CF clear if successful
	    AX destroyed
	CF set on error
	    AX = error code (01h,02h,03h,05h) (see #01680 at AH=59h)
Notes:	will not change volume label or directory attribute bits, but will
	  change the other attribute bits of a directory (the directory
	  bit must be cleared to successfully change the other attributes of a
	  directory, but the directory will not be changed to a normal file as
	  a result)
	MS-DOS 4.01 reportedly closes the file if it is currently open
	for security reasons, the Novell NetWare execute-only bit can never
	  be cleared; the file must be deleted and recreated
	under the FlashTek X-32 DOS extender, the filename pointer is in DS:EDX
	DOS 5.0 SHARE will close the file if it is currently open in sharing-
	  compatibility mode, otherwise a sharing violation critical error is
	  generated if the file is currently open
	DR DOS 3.41/5.0 will silently ignore attempts to change the 'directory'
	  attribute bit
SeeAlso: AX=4300h,AX=4311h,AX=7143h,INT 2F/AX=110Eh