
Marvin Minsky’s Marvelous Meat Machine - steven
https://medium.com/backchannel/marvin-minsky-s-marvelous-meat-machine-f436aec02fdf#.jxy9ralb6
======
DonHopkins
Thanks to hga [1], here is Marvin Minsky's Universal Turing Machine emulator
written in Teco.

    
    
      MSG: APL    1     
      DISTRIB:  *BBOARD
      EXPIRES: 03/17/81 23:08:54
      MINSKY@MIT-MC 03/11/81 23:08:54 Re: too-short programs
      APL is compact, I suppose.  So is TECO.  When I wrote the following
      Universal Turing Machine, which works, I actually understood it.
    
      i1Aul qq+^^0:iqm^[29iiq\356y0L1 00L1 11L2 A1L1
      y0L1 0yR2 1AR2 AyR6 yyL3 00L0 1AL3 A1L4 yyL4 0yR5 11L7 A1L4
      yyR5 0yL3 1AR5 A1R5 yyR6 0AL3 1AR6 A1R6 y0R7 0yR6 11R7 A0R2
      ^[j<sR^[;-d-2ciql-^^^[ci"ed^^^[cii^[ciuq'^[>
      j<sL^[;-d-2ciql-^^^[ci"ed^^^[cii-2c^[ciuq'^[>jxblx1lx2lx3lx4lx5lx6lx7hk
      iyyAyyAyy^[32<i0^[>ji110101110000010011011^[ 1uq<htmbqq=>
    
      I do not advise attempting to understand this code, which is
      almost as bad as that for the Universal Turing machine.
    

[1]
[https://news.ycombinator.com/item?id=10161002](https://news.ycombinator.com/item?id=10161002)

~~~
poseid
for non-computer scientists, but rather for engineers, how do Turing machines
map to the stored-program computer that have instruction sets, stacks, RAM and
ROM ?

~~~
v-yadli
make extensions on the original. use the single tape to simulate multiple
tapes, one for stack(or registers), one for ram, one for rom, and another for
encoding how the hardware behaves against the other tapes.

~~~
JadeNB
> make extensions on the original. use the single tape to simulate multiple
> tapes, one for stack(or registers), one for ram, one for rom, and another
> for encoding how the hardware behaves against the other tapes.

Very nice; that is surely about the best information:length ratio one could
hope for! I hope you won't mind a slight clarification—obvious, I am sure, to
you and to any computer scientist, but not, perhaps, to a non-specialist: this
is _not_ an extension of the original, but rather a _simulation_ within the
original of an apparently more general concept. This is important, because it
means that any theoretical results about the original concept also apply to
its apparent generalisation (e.g., multi-tape Turing machines still can't
decide undecideable problems).

~~~
v-yadli
yep, thanks for the clarification!

------
poseid
really nice writing, but the title "meat machine" ?

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milkytron
I think it's a well thought and appropriate title, considering Minsky joked
around calling humans "meat machines" and the author is acknowledging Marvin's
own mind and body for being marvelous.

