The standardisation procedure of the IEEE P1394.1 Draft Standard for High Performance Serial Bus Bridges is supported through the use of the state-of-the-art model checker Spin, which has been used to simulate the complex net update procedure of the standard, and the use of which will eventually be refined to obtain a solid model checking analysis of the standard. A concise description of net updates is formalised in terms of spanning trees, and it is shown how Spin was used to track down errors in the standard and to gather support for the solutions proposed.