The transmission card has two links to control insertion of CRCs and handshaking commands. The ``HANDLK'' should be set to ``1'' to disable the use of handshaking, and to ``0'' to enable it. The ``CRCLK'' should be set to ``1'' to disable transmission of header CRCs and to ``0'' to enable. In addition the transformers joining the card to the coax line may be placed in the North end of their sockets to put the ECL I/O on the pins linking to the motherboard, or to the South end of their sockets to send the ECL I/O to the COAX connectors on the card itself. Links ``L0'' to ``L7'' should be made if no multi-cast card is in use, and together with the ``P'' and ``M'' points provide the socket for the multi-cast node to plug in.