A physiological monitor has a sensor port configured to attach and communicatewith a sensor. A processor board is in communications with the sensor port andhas a board digital signal processor (DSP). Firmware residing on the processorboard is executable by the board DSP so as to calculate physiological parametersin response to a sensor signal received from the sensor. Upgrade tools are individuallyattachable to the sensor port in lieu of the sensor so as to designate to the processorboard which of the physiological parameters, if any, to calculate when the sensoris attached to the sensor port.
