[vcf-midatlantic] vacuum tube computers, was Re: Museum Report 2017-11-26 November 26, 2017

Jeffrey Brace jeffrey at vcfed.org
Sun Nov 26 21:13:03 EST 2017

How would you explain the George Philbrick machine to an 8 year old? How do
you explain what a vacuum tube actually does to an 8 year old?

On Sun, Nov 26, 2017 at 8:50 PM, Dave McGuire via vcf-midatlantic <
vcf-midatlantic at lists.vintagecomputerfederation.org> wrote:

> On 11/26/2017 04:54 PM, Jeffrey Brace via vcf-midatlantic wrote:
> > The parents love the explanation of the progression of technology. I need
> > to learn more about how vacuum tube computers work to give them a
> > comparison.
>   It's important to realize that there's really no difference.  Vacuum
> tubes are analogous to FETs (field-effect transistors) and are simply
> the active switching element of tube-based digital computers, where
> transistors are the active switching element of solid-state computers.
> The logic...the instruction set, buses, etc...can be identical.  The
> only real reason they're not is because computer architecture has grown
> up alongside, but largely independent of, electronics technology.
>   Now if you're talking about tube-based analog computers, that's a
> different animal...and the same point applies there.  Analog computers
> are (mostly) composed of op-amps, and those op-amps can be built with
> tubes or transistors. (with or without multiple transistors being
> "integrated" into one "circuit", i.e. using integrated circuits)  Again,
> the architecture is (or at least can be) the same.
>   The takeaway here is the importance of understanding the difference
> between architectures and implementations.
>                -Dave
> --
> Dave McGuire, AK4HZ
> New Kensington, PA

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