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A Universal Turing Machine In 100 Punchcards

Posted by timothy on from the animation-to-blow-your-mind dept.

New submitter theclockworkcomputer writes "100 years ago tomorrow, Alan Turing was born. To celebrate, I wrote a Universal Turing Machine in 100 Punchcards. I've uploaded a video to explain a small part of the read head (the Jacquard). One needle is shown out of a total of 28. As this is about a program for a Turing Machine and not about a Turing Machine itself, I hope to be excused from the requirement of infinite tape."

6 of 48 comments (clear)

  1. Linear bounded automaton by tepples · · Score: 4, Insightful

    But what is possible is a universal linear bounded automaton, and that's what physically realized Turing machines become.

  2. Wow you couldn't even read the summary? by Anonymous Coward · · Score: 4, Informative

    This is not a universal Turing machine, since those things are impossible in this universe. Not even humans are universal Turing machines.

    Right. And from excessively short summary:

    As this is about a program for a Turing Machine and not about a Turing Machine itself, I hope to be excused from the requirement of infinite tape.

  3. irony of Alan's death by peter303 · · Score: 4, Interesting

    He was hounded into dangerous therapies because of his sexual orientation. Now the largest computer company in the world is run by a gay man. What would Alan had given us with another 20 years?

  4. Re:Just to be pedantic by tendays · · Score: 5, Informative

    Indeed. Turing machines don't require infinite tapes, they require unbounded tapes. In particular the initial state of the tape must contain at most a finite number of non-blank cells. Working with a finite tape is therefore fine as long as you are ready to enlarge it when the head reaches the boundary (so that, to the machine, it appears infinite). In the same sense, a physical computer could act as a Turing machine if, when it runs out of memory, an operator could come and plug in an extra hard drive (and if memory addresses were made in a way that they can be arbitrarily large).

  5. schematic by theclockworkcomputer · · Score: 4, Interesting

    For who is interested here is a schematic of the machine

  6. How beautiful! by Muad'Dave · · Score: 3, Insightful

    Wow. Regardless of the geek cred you get for making such a beast, let me commend you on the sheer artistic beauty of your website and the video. Just wow.

    --
    Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.