That’s the question [Kathy] asked when she built this LED matrix light pen project. It looks simple enough – a 64-LED matrix illuminates as the pen draws shapes. But how does the circuit ...

Sometimes the simplest of projects end up revealing the most interesting of things, as for example is the case with [Ryo Mukai]’s light pen for the Vectrex console. It’s an extremely simple ...

A light-sensitive stylus wired to a video terminal used to draw pictures or select menu options. The user brings the pen to the desired point on screen and presses the pen button to make contact.