Re: (OT) Lego Turing machine Message #8 Posted by C.Ret on 23 June 2012, 12:35 p.m., in response to message #6 by BruceH
OK! Thank you.
I just review the video at a better Internet connection that allow me to stop, go backward and forward the video.
You are right, in my first quick watch (at low speed connection), I miss a few detail, especially the state of the tape at the end of the process ( which have nothing to do with the 'tape' in the end-credit-generic) !
There is nothing wrong, apparently, the resulting state of the "computed" tape is + o o + o o + o o o o + + + + ... as one may expected.
So, thank you for your analysis, sorry for my miss up first interpretation.
And you are right, what is particular to Turing Machine is that the "paper" (or here "lego") tape is not the 'program', it is just the computation (or result of the computation). The program is somewhere else in the 'internal' ou 'mechanical' - for mechanical setup only - of the Turing machine.
I still wonder how is such a ‘program’ looking, for example able to add two integer values and write the result in the format of this demo:
a + b -> c
express as :
+ o o ... o o + o o ... o o + o o o ... o o o +
a times b times c=a+b times
Example:
+ o o + o o + --> + o o + o o +o o o o+ 2+2=4
+ o o o + o o + --> + o o o + o o + o o o o o + 3+2=5
+ o + o o o + --> + o + o o o + o o o o + 1+3=4
How many internal states and transition rules?
I know to program this on HP41C RPN-machine, but I am really poor in engineering such a program for a Turing-Machine!
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