This computer controlled positive displacement shutter valve dispenser comprises a piston housing, pistons, shutter valves, linear or rotational drive servomechanisms, and a computer controller. The piston housing configuration can be cylindrical or non-cylindrical. Either configuration can have multiple input or output ports selected by the travel of the shutter valve. In addition the non-cylindrical configuration can have a multitude of shapes, allowing for single piston or multiple piston designs. The multiple piston arrangement can have equal or nonequal displacements from the pump cavity of each piston. The computer controls all aspects of the dispenser, including the forward and retract distance, speed and timing of the piston and shutter valves. The amount dispensed can vary between the maximum volume of the pump cavity to a small fraction of its volume as set by the resolution of the controller and linear drive mechanism.