INT 21 - DR-DOS 3.41+ internal - SET ACCESS RIGHTS AND PASSWORD
        AX = 4303h
        CX = access rights
             bits 11-0: access rights (see AX=4302h)
             bit 15: new password is to be set
        DS:DX -> ASCIZ pathname
        [DTA] = new password if CX bit 15 is set (blank-padded to 8 characters)
Return: CF clear if successful
        CF set on error
            AX = error code
Notes:  if the file is already protected, the old password must be added after
          the pathname, separated by a ";"
        this function is documented in DR-DOS 6.0 and corresponds to the
          "Get/Set File Attributes" function, subfunction 3, documented in
          Concurrent DOS.
SeeAlso: AH=0Fh,AH=17h,AX=4302h,AX=4305h,AX=4454h

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