I finally got around to browsing through the most recent issue of Make magazine (vol. 6) this evening. Make really is one of my favorite magazines that explores all sorts of science and technology hobby and hacking projects, tools, techniques, and the hackers who make them. I strongly recommend the magazine to any individual or school interested in fostering innovation or interest in science and technology.
Much to my surprise, when I reached page 176, I found an ad for a reprised version of the very toy my father gave me in the late 1960s that first triggered my interest in computing, and a later realization of the importance of mathematical abstraction applied to real physical systems, and how you can use real physical systems to perform mathematical computations. Ultimately, it led to my Ph.D research in computing with physical systems 25 years later.
The Digi-Comp 1 was Mechanically operated plastic computer made by E.S.R. in 1963, and sold for $6, though I seem to remember getting the toy when I was around eight or nine years old in 1974. At first, I didn’t really get what my father was so excited about. I was more interested in plastic models of tanks and planes. But he persisted and convinced me to help him put it together. When I realized that you could actually make the contraption count, add, subtract, and even play games, just by positioning straws and moving cogs, something important happened in my brain that I didn’t fully appreciate until about 15 years later at Cornell University, when I found the relationships between physics and mathematical abstractions completely intuitive. The very notion that you can represent a number with a straw, and change the count and perform mathematical operations by moving that straw back and forth led quite naturally to the idea that with every more, and tinier straws, then beads on an abacus, then mechanical adding machines, punch cards and paper tapes, magnetic beads, then thin-film transistors in microcircuits, and now electrons in nano-wires form an obvious progression.
Here are some great quotes from other people who also apparently had their lives changed by this little gadget.
I was eleven years old (53 now) when I received a Digi-Comp I for Christmas. I was fascinated with it from a mechanical standpoint and played with it for hours. Even when I had mastered all the programs, I would still get it out and see what it could do. I played with it off and on for a couple of years until it wore out or broke, can’t remember which. I think of it as the spark that got me interested in computing, a career that has been and remains a lot of fun.
My uncle began to teach me about mainframes, showed me Gunner-IV on the GE Timesharing network via teletype and around that time I got a Digi-Comp I. I also began designing primitive switch based computers using multi-pole switches and relays. I tried the old wire wrapped around a nail with tin can contacts all connected directly to house current. Boy were my parents mad. The Digi-Comp was a lot simpler to work with. I think the mystery of how it really worked stayed with me and has only now been solved.
My most quixotic programming effort ever was trying to program perfect tic-tac-toe on my Digi-Comp I in 6th grade. Before I started, I realized tic-tac-toe was a never-lose game with the right strategy. I discovered the rotation and reflection symmetries of the game right away, but I never cottoned on to the fact that there just wasn’t enough memory in old Digi-Comp to get the job done. I filled up a whole sheet of posterboard with the game tree, though.
Every child interested in computing or mechanics should build one of these. Thankfully, you can now purchase an updated version at mindsontoys.
Go forth. Compute with physical objects and be inspired.