Lego Interactive Interface-A Driven via Arduino

Backstory

A number of years ago, a visitor to the LVL1 Hackerspace brought in a box of old Lego items that their father had in storage. The hope was that they would be an interesting project to build something and then use it to demonstrate engineering to children at a science center. The central element was an Interface-A (70455) control unit. The Lego collection also included the Apple II interface card. A working Apple II was not available, so someone suggested driving the "brick" with an arduino.