[HN Gopher] A modern 8 bit design, built using 1950s thermionic ...
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A modern 8 bit design, built using 1950s thermionic valves
Author : cenazoic
Score : 182 points
Date : 2024-06-27 19:18 UTC (3 hours ago)
(HTM) web link (www.valve.computer)
(TXT) w3m dump (www.valve.computer)
| dang wrote:
| [stub for offtopicness]
| GaylordTuring wrote:
| God dammit! I thought Valve had released a stationary computer.
| I was ready to open my wallet even before clicking the link ;(
| Insanity wrote:
| Ha, exact same reaction here!
| artyom wrote:
| Oh man how many of us are out there?
|
| I wasn't disappointed about the actual article tho.
| dang wrote:
| I suppose we'd better change the title before the entire
| thread fills up with variations of this reaction!
| artemonster wrote:
| hl3 not confirmed :(
| dr_dshiv wrote:
| Is that a joke? Because this is the most hackernews article
| ever
| dang wrote:
| Oh the article is thoroughly on topic! I mean the comments
| related to Valve the company. The thread was filling up with
| those before we changed the title. (Submitted title was
| "Valve.computer".)
|
| Sometimes when there are too many offtopic comments like this
| I make a stub comment, move all the offtopic subthreads
| underneath it, and then collapse it.
|
| https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu.
| ..
| 082349872349872 wrote:
| > _When all the valves are glowing, I check the fire extinguisher
| is full, and run the code._
|
| It wasn't until working with valve hardware that I finally
| grokked the original difference between a cold boot and a warm
| one.
| ahazred8ta wrote:
| "And when they turn the power on, it's sure to dim the lamps /
| At plus and minus 16 volts and fourteen hundred amps." -- Frank
| Hayes
| FredPret wrote:
| If Lawrence Pritchard Waterhouse had a blog an a large stock of
| valves, it'd be close to this
| nico wrote:
| What a fascinating project. So cool
|
| Thank you for making it happen and sharing it here
|
| Super interesting read and very inspiring too
| cellularmitosis wrote:
| > 200 amps
|
| Something I've been curious about: is the current actually
| required for the thermionic effect, or just the heat?
|
| Could you lower the current requirement by thermally insulating
| the tubes?
| doe_eyes wrote:
| They are insulated really well - by vacuum!
|
| I'm actually surprised by the figure, though. A small tube
| requires about 300 mA at 6 V, and the trick is that you can
| connect the heaters in series instead of doing it all in
| parallel and pumping out a ton of amps at a very low voltage.
|
| They could've done 10 tubes in series at a reasonably safe 60
| VDC, and they'd only need 20 amps.
|
| Back in that era, because both valves and relays were
| expensive, it was also common to use them more creatively than
| just constructing standard logic gates. You'd try to make a
| full adder or a flip-flop cell as an analog circuit, breaking
| the abstractions we're now used to - but also saving
| components.
| Ductapemaster wrote:
| Current into a low-resistance "heater" element is used to
| produce the heat required for Thermionic Emission [0] in a
| vacuum tube. You only need the heater/emitter to be hot, and
| insulating the tubes would just spread the heat around to
| everything inside of it -- at some extreme, making everything
| into an emitter, instead of elements that control the emission.
|
| [0] https://en.wikipedia.org/wiki/Thermionic_emission
| doe_eyes wrote:
| This is not really accurate. To get meaningful emissions from
| normal electrodes, you need to heat them up to about 2000
| degC. Vacuum tubes operate at 700 degC or something like
| that. The trick is that one electrode is doped with special
| rare-earth additives that greatly increase electron
| emissions. The same treatment isn't applied to the rest of
| the device. So, even if all internal components have the same
| temperature, a vacuum tube can still work (to some extent).
| Ductapemaster wrote:
| 100% correct and I appreciate the additional details! I
| couldn't come up with a good analogy to explain you want
| the emitter as a separate and unique element from
| everything else involved in a tube -- oversimplified in the
| process.
| mrob wrote:
| Perhaps the inside of the tube could be coated with a thin
| layer of gold using evaporative deposition before the
| grid/plate/filament/etc is added, like on spacesuit visors for
| IR reflection.
| mannykannot wrote:
| I did a quick search for the specs, and, if I am reading it
| right, Wikipedia [1] gives the filament current as being 350mA
| at 6.3V, a dissipation of 2.2W. As that current sums to 196A
| for the 560 tubes, I suspect this is what the 200A figure
| refers to.
|
| As the tubes are at high vacuum, they are already well-
| insulated, so I imagine that most of the heat loss is via
| infra-red radiation. I have a very vague recollection that, in
| thermionic tubes, the anode has to be kept reasonably cool so
| that it is not emitting electrons itself. I would be surprised
| if there are any low-hanging fruit to be plucked here,
| especially given that vacuum tubes were important technology
| for a half-century.
|
| [1] https://en.wikipedia.org/wiki/6N3P
| an_aparallel wrote:
| The high voltage from my understanding is to be able to handle
| the high inrush current to the heaters on power up, I believe
| after that the requirements are lower (parroting what I've read
| written by Eric Barbour on his metasonix vacuum tube
| synthesizers)
| Prcmaker wrote:
| Really it's both ways in terms of required current. The
| thermionic effect requires filament heat, which since being a
| filament, take some amount of current, often around half an
| amp, some more some less. A filament could, in theory, be run
| at any current though so long as the power through the filament
| stays the same and the voltage is kept low enough not to arc to
| adjacent parts. There is likely also a minimum current
| requirement (since you need a source for those free electrons),
| which often then implies some non-linearity at the low end.
|
| As others have mentioned, the 200amps of this case could be
| reduced substantially by running filaments in series (can be
| done with 6.3v heaters as the error from a common 5v or 9v
| supply is more than if you pair them up and use a 12V supply)
| though this introduces the failure mode of old Christmas tree
| lights.
|
| Source: I make vacuum tubes.
| creer wrote:
| There are tubes made which share one heater. For an exotic
| example with a working web page, see this tube where two
| triodes and one pentode share the same one heater filament.
|
| https://vinylsavor.blogspot.com/2021/11/tube-of-month-6bh11....
|
| This one has two diodes and two triodes.
|
| https://vinylsavor.blogspot.com/search/label/6AY11
|
| And in this very design, they chose "6N3P valve contains 2
| triodes around a single heater, halving the physical size and
| power requirements."
|
| There may have been tubes made where the triode function can be
| pretty rough (sufficient for a digital circuit) and several of
| them could share one enclosure. In the tubes shown above,
| apparently the limit was the number of pins on the socket - but
| also that all these active elements do not share any pin.
|
| Insulating the whole thing would run into issues like burning
| wire insulation.
| nicetryguy wrote:
| Great for the winter! In all seriousness, amazing work. It's been
| tough to get tubes lately with the whole Ukraine situation
| sadly...
| orbat wrote:
| > Every one agrees that the Turner Prize is much more than just a
| display of virtue signalling by the cultural elite, and I have
| decided to enter the Valve.Computer for the prize.
|
| Uh, what? Where did this sudden "virtue signaling" by the
| "cultural elite" stuff come from?
| bentt wrote:
| "But most important of all, is to have a lovely wife, who knows
| you're daft as a brush, and that life together is brilliant."
|
| Hold out for the partner that cheers you on when you're doing
| what you love.
| naikrovek wrote:
| > Hold out for the partner that cheers you on when you're doing
| what you love.
|
| If only it were that easy. Those kinds of people are few and
| far between. I'm almost 50 and I don't think I've ever even met
| a woman who has actively encouraged me about a single thing.
| I've been married twice and have 4 daughters.
| anonzzzies wrote:
| Hence the hold out. I (50m) didn't meet her until I was 30:
| until that time I dated and had few months relationships with
| a lot but it never felt quite right. Which became blatantly
| obvious when I met my current wife.
| cududa wrote:
| Very cool. Couldn't get the pictures to load in any higher res.
| Would love to see more of the detail
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(page generated 2024-06-27 23:00 UTC)