Recently I had to replace a 4-way switch, an electrical component that lets you turn a light on or off from three or more locations. While installing it, I thought about the binary properties of my three-switch circuit: I saw powers of two, binary logic, and binary gray code. I drew some diagrams, including a state machine. I’ll share my thoughts and diagrams with you in this article.
The other day my son showed me a page in a Star Wars® book which described a character named Ki-Adi-Mundi, who up until that point we knew as “big brain head.” I read in his bio that he has a binary brain, at which point I exclaimed, “Hey, just like me!” Well, not quite — his is binary in a different sense:
The Binary Marble Adding Machine is a device that adds binary numbers mechanically. It uses wood instead of silicon, gravity instead of voltage, and marbles instead of current. We don’t need no stinkin’ CMOS!
The machine may be more cool than practical, but it certainly is educational. It illustrates basic principles of binary numbers, binary arithmetic, and binary logic. Let’s take a closer look.