Device Data Word

�F�E�D�C�B�A�9�8�7�6�5�4�3�2�1�0� Device Data Word

� � � � � � � � � � � � � � � +---- 1 = standard input device

� � � � � � � � � � � � � � +---- 1 = standard output device

� � � � � � � � � � � � � +---- 1 = NUL device

� � � � � � � � � � � � +---- 1 = clock device

� � � � � � � � � � � +---- reserved

� � � � � � � � � � +---- 1 = binary mode, 0 = translated

� � � � � � � � � +---- 0 = end of file on input

� � � � � � � � +---- 1 = character device

+------------------ reserved, must be zero