A modern 8 bit design, built using 1950s thermionic valves

&gt; <i>When all the valves are glowing, I check the fire extinguisher is full, and run the code.</i><p>It wasn&#x27;t until working with valve hardware that I finally grokked the original difference between a cold boot and a warm one.

&quot;But most important of all, is to have a lovely wife, who knows you&#x27;re daft as a brush, and that life together is brilliant.&quot;<p>Hold out for the partner that cheers you on when you&#x27;re doing what you love.

This guy is the right kind of crazy. This is truly what the internet was made for: sharing our outlandish, over-the-top projects with others. Awesome writeup!

If Lawrence Pritchard Waterhouse had a blog an a large stock of valves, it&#x27;d be close to this

&gt; 200 amps<p>Something I’ve been curious about: is the current actually required for the thermionic effect, or just the heat?<p>Could you lower the current requirement by thermally insulating the tubes?

Now I&#x27;d truly love that computer as a talking point in say the rumpus room of my house, I could entertain my techie friends for hours. And it would take on extra importance in winter in keeping my house warm.<p>I&#x27;ve not used 6N3P tubes before but looking at the circuit it seems to me a 12AT7 (an old favorite of mine) would substitute in that circuit almost without alteration. Then again with a tweak or two either the higher gain 12AX7 or its lower gain cousin the 12AU7 would do.

Having become accustomed to helping a friend fix old ham radio gear, 80 volts doesn&#x27;t strike me as terribly dangerous.<p>In some of this stuff, over half of the power supplies output was dumped as heat in resistive divider networks just to bias things correctly and ensure operation. The filaments worked out to less than a fifth of the load in many cases.<p>Coming from a background of transistors and chips, it was wild to see so many 5 watt or more resistors in use.

Great for the winter! In all seriousness, amazing work. It&#x27;s been tough to get tubes lately with the whole Ukraine situation sadly...

This is so interesting! Quite often, I&#x27;m thinking about how a modern design would perform with tubes. Back in the 40s and 50s, digital computers were new. Much of the design was inherited from tabulating machines. When I study the early IBM machines, they seem very complex. When we learned more during the 60s, and ended up with microprocessors in the 70s, the design had been optimized a lot. So I have been wondering how a &quot;modern&quot; design would perform on tubes.<p>This guy actually did it. What a fun project it must have been. Super interesting read.<p>One detail in the introduction that made me a bit puzzled: &quot;The Valve.Computer is an 8 bit computer, with the usual 12 bit address and data buses&quot;. In an 8 bit CPU, we had &quot;the usual 16 bit address bus and the 8 bit address bus&quot;.

It&#x27;s really cool to design all those NOR gates using thermionic valves, as shown in the schematics in the middle of the article. I just wonder if using two regular diodes in the input paths of each NOR gate and another diode in the output path is a little bit of &quot;cheating&quot;, since diodes are somewhat newer technology than thermionic valves.

What a fascinating project. So cool<p>Thank you for making it happen and sharing it here<p>Super interesting read and very inspiring too

I was really hoping to see a picture of it in dim light with the valves glowing. Also I was not expecting to see such an adorable light house for ducks in the post. All around a great read :)

Very cool. Couldn’t get the pictures to load in any higher res. Would love to see more of the detail

That’s some serious power draw. Truly impressive work!

I&#x27;m now wondering if someone ever tried to build a small computer&#x2F;calculator with steam valves

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&gt; 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.<p>Uh, what? Where did this sudden &quot;virtue signaling&quot; by the &quot;cultural elite&quot; stuff come from?