Plotter
A device for drawing on paper using a pen guided by motors. Printers of all types are limited by having a small printable area. Up to A3 size is available, at a cost, but these machines are very expensive. Most printers are designed for A4 page production. To cover a larger area than this, e.g., for architectural or electrical wiring plans, a plotter is useful. Plotters are readily available for paper sizes up to A0. No printer which needs to store of the states of individual dots can possibly accommodate such a paper size. Plotters work by driving a pen under motor control. The computer specifies the required shapes in terms of pen position; the plotter moves the pen to the required position using separate X- and Y-axis motors. Plotters use stepper motors to obtain fine control of position. Most plotters can produce colour output, by picking up one of a selection of coloured pens.