Frequently Asked Questions and Comments
Who are you and why did you build the Turing machine?
I live in northeast Wisconsin and love to build things. I've always liked to make things, take things apart, and see how stuff works. I've made all sorts of things, from a CNC router to a Gingery metal lathe, from a greenhouse to furniture; it doesn't really matter, I find it all enjoyable. I'm also fortunate that, while they may not always understand what I'm building, my family has always been supportive.
The Turing machine came about from a long interest in the history of computers. It's amazing how groundbreaking computer concepts that were developed during the 40's and 50's are now often taken for granted. Something that today seems as basic as the flip-flop or a stack were hard-won ideas in their day. The Turing machine is that type of concept; although it seems almost trivial today, is it still conceptually so powerful.
While thinking about Turing machines I found that no one had ever actually built one, at least not one that looked like Turing's original concept (if someone does know of one, please let me know). There have been a few other physical Turing machines like the Lego of Doom, but none were immediately recognizable as Turing machines. As I am always looking for a new challenge, I set out to build what you see here.
You said "_____ _____", but you really should have said "______ ___ _______".
You'll find that I have taken liberty with many of the classic terms and descriptions used with Turing machines. I've done this because I've wanted to explain the concept of a Turing machine to the "non-math" people reading this. If you understand the concept of a Turing machine you certainly don't need my explanation to understand what I'm presenting here. If you have a better way of explaining something to a non-math literate person, I'd love to hear it and will work to incorporate it into the site.
Will you build one for me?
It's unlikely that I will ever build another one. I get enjoyment out of creating and building something the first time. It's the journey of discovery and newness that makes it worthwhile, and I don't find building something the second or third time to be as much fun.
Would you consider giving it to a museum?
A number of people have ask about the future of my Turing machine and if I would consider lending, selling or donating it to a museum. I generally build for the thrill of creating and not for long term ownership. In a year or so, after I have taken the Turing machine to a few meetings and expos I will be looking for a home for it. I can think of no greater reward than to have something I've build in a place where a wide range of people can see it every day. I've already been contacted by a number of museums and when the time comes you can be sure I will be in contact with them.
Update: The Turing machine is currently on display at the Powerhouse Museum in Sydney, Australia. If you happen to be in the Sydney area, be sure to stop by and check it out. It will be returning to the United States sometime in August 2012 and will head to Harvard Universitiy's Collection of Historical Scientific Instruments. Finally, latter in 2012, the Turing machine will go on long term/permanent display at the Computer History Museum in Mountain View, California.
Why did you use a Propeller Chip?
I thought the Propeller chip fit the project really well. It had the required number of IO pins and I knew the multiple processors would come in handy with some operations. I have used the Propeller for a few other projects and while I have somewhat of a love/hate relationship with it, in general I really like it. I also already had code that did many of the things I needed to do. Last but not least, I had one sitting around not doing anything.
What's your next project?
You could say I'm shifting gears a little and building a wooden
(The clock was finished in September 2010. This is a video of it in operation.)
I'm also doing some iOS developement, so if you feel like buying something from me, check out, toycartools.com. My first app, Tapulator, is done. Tapulator is a quick and easy way to count and calulate the production speed of many processes.
Online Turing Machine Simulators
Here are a couple of simulators that will let you experiment with creating your own Turing machines.
Programming the Propeller Microcontroller
Get the authoritative guide to the Parallax Propeller chip.
The Essential Turing
The papers in this book are the key works for understanding Turing's phenomenal contribution.