A method performed by a computer system is provided. The instruments can include portions that allow for positive and rigid engagement with a selected prosthesis member to allow for positioning it relative to the anatomy. If an Mth time slot of a time frame is available, the base unit sends this message in the Mth time slot and receives a message having channel measurement data in the Mth time slot of the next time frame. The calculation of the memory address for the current portion of the plurality of information bits may be achieved without the use of a buffer.