A one-way valve allows air to be drawn from a collapsible, flexible, airtight bag using a vacuum source. This watch includes an interface device for controlling a computer cursor. When printing a color print job, less than all of the light emitting sources in the black image transfer assembly are used. Advantageously, an effort is made to avoid having to inform the corresponding media gateway controller of the move, thereby minimizing any discontinuity in each moved packet stream. The sense amplifier for a bit line compares the output of a memory cell for that bit line with the output of one of the plurality of reference cells for that bit line. The sensor converts the measured values detected in analog by the mass flow rate sensor element and the temperature sensor element into digital output signals.