On Sunday, October 11, 2020, 5:08:35 AM EDT, Jeffrey Jonas via vcf-midatlantic <vcf-midatlantic@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