An input device from french company M.M.C. for use with CAD software. The pencil is attached to potentiometers, and works much like a top-down analogue joystick. The pencil does also have a "fire" button, allowing to start/stop drawing.
Note: Many people seem to think that the Graphiscop is a plotter - it isn't. At first glance it does actually look a bit like that, but in practice it should be mechanically impossible for hardware to move the pencil at that angle - a plotter would require to have much more robust mechanics.