The plotter consists of a rotating drum and a pen holder which can be moved horizontally over the drum. The pen can be lowered and raised by a solenoid. The movement in x-axis (the pen) and y-axis (the drum) is performed by two four-phase step motors.
The plootter is to be controlled by a microcomputer, consisting mainly of a Motorola 68008 microprocessor on a card containing RAM, ROM and serial communication devices.
The criteria we set up for the product, was that it should be able to generate straight lines between two arbitrary coordinates on the plottable area. The coordinates, to which the pen is to be moved, should be read from a hexadecimal keyboard (0-F). The program should provide feedback from the system via an 8-char HP led display. After a moving cycle, the program should stop and read new coordinates and ask whether the pen should be lowered (draw) or raised (move) for the next moving cycle.