System and method for controlling the presentation of information, such as dynamically displayed text, includes a computer with a display device and one or more sets of electrode plates and capacitive field sensors arranged facing each other on a substantially flat and substantially stationary surface, such as a table top. In a one embodiment, the system includes a cutting assembly, sensors upstream of the cutting assembly and a programmable logic controller. The first and second pistons each preferably include a sealing head which seats in a tapered frusto-conical shaped seat for positively sealing the vacuum inlet and the vent port in the operation of the valve.