[phyrrus9]

So I know all of you are familiar with at least the concept of vacuum tubes in computing history, but who can say they can actually build things out of them?

Take a look at the below screenshot, which is a diagram for a pretty basic analog single-purpose computer. In this case, it would have 2 dials and 3 screens. Dials labeled A and B (the VRs in here), with corresponding voltmeter displays (also shown), and then a voltmeter labeled Q.

This diagram shows a simple computational circuit that runs the function

Code:

-2 * (A + B)

Of course, there are more interesting circuits, but I don't want to write them up and have no interest. Let me know if you want to learn about this stuff.

btw, you can play with the simulator of this circuit here

[BurritoBeans]

So I know all of you are familiar with at least the concept of vacuum tubes in computing history, but who can say they can actually build things out of them?

Ooh, ooh, me! I made a (*basic) thread on building guitar amps and almost did two more on radios and Additron-based circuits.

Seriously though, I've never messed with analog parts like tubes, etc. in computing outside of limited use of an IBM 709, my PDP-8, and some basic calculators - if there's enough interest and you're willing to I'd love to see a thread.

[phyrrus9]

So I know all of you are familiar with at least the concept of vacuum tubes in computing history, but who can say they can actually build things out of them?

Ooh, ooh, me! I made a (*basic) thread on building guitar amps and almost did two more on radios and Additron-based circuits.

Seriously though, I've never messed with analog parts like tubes, etc. in computing outside of limited use of an IBM 709, my PDP-8, and some basic calculators - if there's enough interest and you're willing to I'd love to see a thread.

You've almost certainly used analog components. Vacuum tubes were usually operational amplifiers (now replaced with IC741) in different configurations. Building our analog circuits today we could easily swap out those IC chips with tubes, at the cost of a great deal of power efficiency and some slight data precision loss.

Ironically, the internals of IC741 are mostly digital today