A communication. system includes two high speed communication links formed by pairs of transformers at either end thereof. A phantom circuit formed by the pairs of transformers is used to distribute power to devices connected to the high speed links. In transmission part of a communications system, data is transmitted under the control of a continuously variable frequency clock. Transmission is on parallel data-strobe links, and the receive includes circuitry to identify on which parallel the data signal is preset. A method and circuitry is provided for transmitting and receiving dc balanced data strobe signals.