[vcf-midatlantic] slight diversion, was "Looking for some knowledgeable with the Harvard Mark I"

Brian L. Stuart blstuart at bellsouth.net
Sun Oct 11 11:41:23 EDT 2020


On Sunday, October 11, 2020, 5:08:35 AM EDT, Jeffrey Jonas via vcf-midatlantic <vcf-midatlantic at lists.vcfed.org> wrote: 
> Jim Scheef:
>> My memory sort of distills down to the factoid
>> that the Mark I had almost no ability to branch in a "program"
>
> That's why the "Turing machine" is so important:
> it describes the bare minimum required for true automatic operation.

To be honest, the lack of conditional operation in
the Mark I always confused me a little.  It always
seemed to me that Aiken saw himself as Babbage's
intellectual heir.  And at least as I read Babbage,
he did recognize/foresee the value in conditional
operations.  So I've never been clear on whether
Aiken didn't see that in Babbage's writing or he
didn't known how to implement conditionals or
even consciously omitted them for expedience
in the first machine.

It may seem a little odd to suggest that conditional
operation could be implemented on a machine
sequenced by paper tape.  However, it actually
would not have been particularly difficult to
implement a conditional skip.  Coupled with
the multiple tape readers and the ability to
switch from one to another, I think it could have
been quite interesting.  It would be an interesting
what-if experiment someday.

BLS


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