That's cute. What's the memory? It ought to be a delay line, for traditional reasons.
I'd have thought a Williams tube would be ideal?
A Vacuum Tube Single Board 1-Bit Computer [video]
21–30 of 42 posts
Re: A Vacuum Tube Single Board 1-Bit Computer [video]
#22Why would you use tubes if you're not making guitar distortion? Do you really need pentodes at the speeds involved? It looks like the guy is toggling a switch by hand to generate a clock signal. Pentodes are devices for RF amplification. Those 6AU6 tubes are 7 pin units, but they contain only one pentode element. Two pins for the heater, then five pins to hook up the pentode. There exist common 8 or 9 pin tubes that…
We could just as easily ask why would you use tubes for guitar distortion?
Hollow state devices saturate differently than solid state devices. Although FETs have similar saturation curves as tubes/valves (sometimes called "glass FETs" - both are voltage amplifiers while transistors are current amplifiers). The fuzz in most guitar amps is the hard saturation that transistors do. So I guess using tubes/valves for guitar distortion is a fashion/trend. There are a number of pre-amps for electric guitars that use tubes/valves to recreate some sounds from the 40s-60s.
Re: A Vacuum Tube Single Board 1-Bit Computer [video]
#23Earlier quoted context omitted.
Considering the primary use case seems to be for public demonstration, the tubes are a good way to get people to look at it. I have a sneaking suspicion that the creator might also like tubes . What's the concern with using tubes? Do you really need tubes for guitar distortion?
Vacuum tubes are his specialty area. He's building a much larger vacuum tube computer and this is supposed to be a more mobile display version he can demo at events. He's also done quite a few videos restoring old vacuum tube based test equipment from like HP. He does some really cool work.
Well, he described the single board version as a trainer: a way to demonstrate how the larger model works. That's likely why the address/data lines are toggle switches and the close is a button. People can setup the state then execute when ready. The much larger version is the thing you see behind him on the wall (it is a work in progress). It is also intended to go to events, but it is much harder to understand ... thus the trainer.
Re: A Vacuum Tube Single Board 1-Bit Computer [video]
#24Earlier quoted context omitted.
This is a demonstration board for the bigger brother, UE-1. UE-1 will be driven by paper tape, though core memory keeps being discussed. I don't think they are considering delay lines -- might be too challenging/fiddly.
Torsion wire delay lines seem pretty DIY friendly, and resistant to interference. They've been used in low-end computers for a reason. (in contrast to the core memory)
Delay lines are fascinating, but I don't see why this is easier than core memory; seems like you are trading an electronics problem for a mechanical one. Regardless, at the speeds they are targeting, I think delay lines might be difficult.
Another interesting option (for ROM) is core rope memory. CuriousMarc has the ultimate explanation: https://www.youtube.com/watch?v=hckwxq8rnr0
Re: A Vacuum Tube Single Board 1-Bit Computer [video]
#25Why would you use tubes if you're not making guitar distortion? Do you really need pentodes at the speeds involved? It looks like the guy is toggling a switch by hand to generate a clock signal. Pentodes are devices for RF amplification. Those 6AU6 tubes are 7 pin units, but they contain only one pentode element. Two pins for the heater, then five pins to hook up the pentode. There exist common 8 or 9 pin tubes that…
Considering the primary use case seems to be for public demonstration, the tubes are a good way to get people to look at it. I have a sneaking suspicion that the creator might also like tubes . What's the concern with using tubes? Do you really need tubes for guitar distortion?
> Do you really need tubes for guitar distortion?
Technically no. But most professional guitarists still swear by tube driven amps. Solid state is getting better every day, but I think we're still a long way out before most guitar players give up their tube amps.
I am perfectly happy with my Line6 Helix, but a few friends still turn their noses up at it.
Re: A Vacuum Tube Single Board 1-Bit Computer [video]
#26Earlier quoted context omitted.
Torsion wire delay lines seem pretty DIY friendly, and resistant to interference. They've been used in low-end computers for a reason. (in contrast to the core memory)
Delay lines are fascinating, but I don't see why this is easier than core memory; seems like you are trading an electronics problem for a mechanical one. Regardless, at the speeds they are targeting, I think delay lines might be difficult. Another interesting option (for ROM) is core rope memory. CuriousMarc has the ultimate explanation: https://www.youtube.com/watch?v=hckwxq8rnr0
Because, if you're using tubes, you don't want a huge number of them. Core memories need many drivers and sense amplifiers. Delay lines are inherently 1-bit devices.
Re: A Vacuum Tube Single Board 1-Bit Computer [video]
#27Why would you use tubes if you're not making guitar distortion? Do you really need pentodes at the speeds involved? It looks like the guy is toggling a switch by hand to generate a clock signal. Pentodes are devices for RF amplification. Those 6AU6 tubes are 7 pin units, but they contain only one pentode element. Two pins for the heater, then five pins to hook up the pentode. There exist common 8 or 9 pin tubes that…
We could just as easily ask why would you use tubes for guitar distortion?
Mainly because the dead simple circuits (common-cathode class A amplification stages taken out of a textbook) produce the sought-after tones. Nothing needs to be contrived other than some resistor and capacitor values for a certain tonal profile you may be looking for.
I prefer to have solid state almost everything, including the power amp; but there should be a couple of tubes in there for making noise.
Re: A Vacuum Tube Single Board 1-Bit Computer [video]
#28Why would you use tubes if you're not making guitar distortion? Do you really need pentodes at the speeds involved? It looks like the guy is toggling a switch by hand to generate a clock signal. Pentodes are devices for RF amplification. Those 6AU6 tubes are 7 pin units, but they contain only one pentode element. Two pins for the heater, then five pins to hook up the pentode. There exist common 8 or 9 pin tubes that…
Idk. Why not just simulate it on your Ryzen 9?
- Because it's not a hardware project at all then. Using transistors versus tubes is still a hardware project on the same level of abstraction.
- You've not gotten away from hardware; it's still there.
- You're using billions of transistors to simulate the operation of dozens of transistors/tubes, which is inelegant. The chip with those transistors may be small, much smaller than your project, but, in theory, your design with the few dozen transistors could be shrunken down to a chip that would be barely visible to the naked eye.
Re: A Vacuum Tube Single Board 1-Bit Computer [video]
#29Why would you use tubes if you're not making guitar distortion? Do you really need pentodes at the speeds involved? It looks like the guy is toggling a switch by hand to generate a clock signal. Pentodes are devices for RF amplification. Those 6AU6 tubes are 7 pin units, but they contain only one pentode element. Two pins for the heater, then five pins to hook up the pentode. There exist common 8 or 9 pin tubes that…
Considering the primary use case seems to be for public demonstration, the tubes are a good way to get people to look at it. I have a sneaking suspicion that the creator might also like tubes . What's the concern with using tubes? Do you really need tubes for guitar distortion?
> What's the concern with using tubes?
Reliability/longevity, power draw/dissipation, high or higher voltages.
(Speaking of the latter, I wonder what plate voltages the guy is using. I'm guessing it could be well below 100V.)
Re: A Vacuum Tube Single Board 1-Bit Computer [video]
#30Earlier quoted context omitted.
Considering the primary use case seems to be for public demonstration, the tubes are a good way to get people to look at it. I have a sneaking suspicion that the creator might also like tubes . What's the concern with using tubes? Do you really need tubes for guitar distortion?
> Do you really need tubes for guitar distortion? Technically no. But most professional guitarists still swear by tube driven amps. Solid state is getting better every day, but I think we're still a long way out before most guitar players give up their tube amps. I am perfectly happy with my Line6 Helix, but a few friends still turn their noses up at it.
Solid state per se isn't getting better¹. Software simulation of tubes ("software state"?) is getting better, or has been (it may have plateaued).
Tubes are still the reference model.
All the DSP cores in a modern amp are just a cover band playing tube tones.
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1. I mean other than digital solid-state getting more highly integrated and faster, to run more complex software. The necessary analog audio paths in a DSP system aren't getting better.