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