4 ms·

This reminds me of the beautiful WITCH a.k.a the Harwell Dekatron which sits in the national museum of computing in the UK. It's sadly overshadowed by the much

This reminds me of the beautiful WITCH a.k.a the Harwell Dekatron which sits in the national museum of computing in the UK. It's sadly overshadowed by the much larger bletchley park museum that is just next door but it contains the original working COLOSSUS and other really early computing efforts. But the reason I love the WITCH is that all of it's memory is stored in decimal using dekatron memory, and it glows with numbers, allowing you to see the memory and registers being shifted around as it operated. Combining this with the awesome debug stepper that is literally a physical button to move onto the next cpu instruction or sub-instruction, and you can really get a sense for the early computer architecture and how ideas for CPU design came about.

rootbear 7y ago
I saw that system a couple of years ago and loved it. It has hundreds of flashing, spinning dekatron tubes, er, valves, and the control logic is relay based, so it makes lots of clicking noises. It's the apotheosis of the 50s sci-fi movie image of a computer. It is the oldest original working digital computer in the world. (Other systems, like the Colossus, are rebuilds.)
a-dub 7y ago
I don't think the collosus at Bletchley is actually original. IIRC, most of the working big machines at Bletchley were reproduced from memory (story goes that all the machines and plans were destroyed after the war because it was "too dangerous" to have them fall into the wrong hands) by the retired telephony engineers who worked on the originals as a sort of hobby club for retirees. There was a full time guy named Tony Sale who I think organized these efforts who would be there hacking away on stuff and was happy to talk about all of it...
- rst 7y ago
  It is a reconstruction -- built from components similar to those of the original machines, but probably varying from the originals in minor detail because the original plans were also destroyed. The rebuild project and the fate of the original machines is summarized briefly in https://en.wikipedia.org/wiki/Colossus_computer#Influence_and_fate https://en.wikipedia.org/wiki/Colossus_computer#Influence_an...
adolph 7y ago
Wow, that isn't Olivetti beautiful, but beautiful in its own way. https://en.wikipedia.org/wiki/Harwell_computer#/media/File:Harwell_Dekatron_Computer_front_view.JPG https://en.wikipedia.org/wiki/Harwell_computer#/media/File:H...

rootbear 7y ago

I saw that system a couple of years ago and loved it. It has hundreds of flashing, spinning dekatron tubes, er, valves, and the control logic is relay based, so it makes lots of clicking noises. It's the apotheosis of the 50s sci-fi movie image of a computer. It is the oldest original working digital computer in the world. (Other systems, like the Colossus, are rebuilds.)

a-dub 7y ago

I don't think the collosus at Bletchley is actually original. IIRC, most of the working big machines at Bletchley were reproduced from memory (story goes that all the machines and plans were destroyed after the war because it was "too dangerous" to have them fall into the wrong hands) by the retired telephony engineers who worked on the originals as a sort of hobby club for retirees. There was a full time guy named Tony Sale who I think organized these efforts who would be there hacking away on stuff and was happy to talk about all of it...

rst 7y ago
It is a reconstruction -- built from components similar to those of the original machines, but probably varying from the originals in minor detail because the original plans were also destroyed. The rebuild project and the fate of the original machines is summarized briefly in https://en.wikipedia.org/wiki/Colossus_computer#Influence_and_fate https://en.wikipedia.org/wiki/Colossus_computer#Influence_an...

adolph 7y ago

Wow, that isn't Olivetti beautiful, but beautiful in its own way. https://en.wikipedia.org/wiki/Harwell_computer#/media/File:Harwell_Dekatron_Computer_front_view.JPG https://en.wikipedia.org/wiki/Harwell_computer#/media/File:H...