Jeff Get an old smart phone and open it up to expose the circuit board, show to the visitor and ask the person to note how small the individual components are, like a little city. Many differnt types of components Then, say before computer board components got small enough to make things like smart phones possible they used tubes and other larger components to do the same sort of things. Tubes used a lot more power and generated a lot more heat than today's equivalents. If a smart phone was full of tubes and associated 50's era components instead of today's smaller components the phone would have to be the size of Camp Evans. The MIT machine we have in the museum display is not anything like a cell phone however it's an analog computer sort of. Its more actually a bunch of Philco analog rack units that would have been part of a larger system plus a plotter and instruments generating "input". I have materials at my house that explain some of the rack components I promise next time I come up I'll try to put something together to explain what the MIT computer likely would have done. Also, as they are now the rack components are in a disorganized impractical configuration. We need to put them together into a more likely configuration asap. That would be a good thing to do next workshop. The process of researching the components will help expose it's function and help docents explain it. As Dave said, an analog computer used tubes for different reasons than a digital computer with logic tubes. There were many different kinds of tubes then, as today there are different kinds of transistors. Bill Degnan twitter: billdeg vintagecomputer.net On Nov 26, 2017 9:22 PM, "Evan Koblentz via vcf-midatlantic" < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
8 yrs is probably too young for us to explain any such details. With a child that young, I just tell them computers used to be this large when their grandparents or greatgrandparents were their age, and leave it at that. For teens or precocious adolescents (or clueless adults!), I explain that a vacuum tube is simply a predessor to transistors but that it does the same basic thing: it gets electrified to represent a digital 1 or turned off for a digital 0. If they want to know how a tube or transistor * actually works * then I suggest they visit the radio museum. :)
On Nov 26, 2017 9:13 PM, "Jeffrey Brace via vcf-midatlantic" < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
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@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