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Megaprocessor – A micro-processor built large (2016)

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Re: Megaprocessor – A micro-processor built large (2016)

#31

Post by Sander_Marechal »

kohsuke wrote: post #18
temeritatis wrote: post #7

I often wondered i could build some sort of general computing machine if we were pushed back to the dark ages or something. I guess you have to define exactly at what level of technological achievements we were pushed back to. But with the knowledge we have today, and without ICs (or advanced manufacturing facilities) and only "simple electronics" (whatever that would be) if this would be possible. Fun stuff to think…

I forgot which book it was (maybe "the three body problem"?) but there was a science fiction story where a Chinese king makes his soldier act as a logical gate and his army becomes a computer. I was like, wow, I didn't think about that, but it totally makes sense!!

There's an XKCD for everything :-) https://xkcd.com/505/

Re: Megaprocessor – A micro-processor built large (2016)

#32

Post by ezconnect »

temeritatis wrote: post #7

I often wondered i could build some sort of general computing machine if we were pushed back to the dark ages or something. I guess you have to define exactly at what level of technological achievements we were pushed back to. But with the knowledge we have today, and without ICs (or advanced manufacturing facilities) and only "simple electronics" (whatever that would be) if this would be possible. Fun stuff to think…

In the dark ages you can build gears. Gears can do arithmetic and calculus.

Re: Megaprocessor – A micro-processor built large (2016)

#34

Post by Joker_vD »

kens wrote: post #30
temeritatis wrote: post #7

I often wondered i could build some sort of general computing machine if we were pushed back to the dark ages or something. I guess you have to define exactly at what level of technological achievements we were pushed back to. But with the knowledge we have today, and without ICs (or advanced manufacturing facilities) and only "simple electronics" (whatever that would be) if this would be possible. Fun stuff to think…

Looking historically, you have a bunch of options for a pre-IC computer; there were lots of pre-IC computers. Transistors, of course, or vacuum tubes give you a useful computer. You can build a computer from relays, but the performance is pretty bad. Memory is also very important. Magnetic core memory is the way to go if you don't have ICs. None of this is going to help you if you went to the dark ages. As far as mec…

For arithmetic, pinwheel calculator (aka "Odhner's arithmometer") [0] is a pretty decent and reliable mechanical device. You can even give it an electric motor for doing the rotations for you and a numerical keyboard.

[0] https://en.wikipedia.org/wiki/Pinwheel_calculator

Re: Megaprocessor – A micro-processor built large (2016)

#35

Post by TheOtherHobbes »

temeritatis wrote: post #7

I often wondered i could build some sort of general computing machine if we were pushed back to the dark ages or something. I guess you have to define exactly at what level of technological achievements we were pushed back to. But with the knowledge we have today, and without ICs (or advanced manufacturing facilities) and only "simple electronics" (whatever that would be) if this would be possible. Fun stuff to think…

First gen transistor computers often used standard functional units - gates, flip flops, and such - packaged into small modules with edge connectors and wired together with wire wrap on a backplane. Like this DEC PDP-8.

http://www.oldcomputers.arcula.co.uk/files/images/pdp8104.jp...

It's fairly easy to design a computer like this.

Later TTL/CMOS designs replaced the packaged modules with much smaller 74xx/40xx ICs.

You can make basic logic gates with just diodes and resistors, but you need transistors for inversion, buffering, and a usable flip flop.

That's probably the minimum level for useful computing/calculating. If civilisation has ended and you have no transistors you probably don't have the resources to make glass valves either, so that's going to be a problem.

Of course there's always clockwork...

Re: Megaprocessor – A micro-processor built large (2016)

#36

Post by adrianN »

sudosysgen wrote: post #29
adrianN wrote: post #19

Earlier quoted context omitted.

There are many people on the internet researching how basic things can be made in a low-tech fashion. I particularly enjoy https://simplifier.neocities.org/ for example. But if you read those blogs you still notice the mind boggling height of the giants whose shoulders the bloggers stand on. Having access to simple chemicals like acids or various salts for example is huge. I wouldn't even know where to start if I had…

The Dr. Stone manga provides an interesting perspective on how you'd bootstrap that chemistry kit.

219 chapters and ongoing. Whew. This confirms my suspicion that bootstrapping is really hard.

Re: Megaprocessor – A micro-processor built large (2016)

#37

Post by umvi »

galcerte wrote: post #23
temeritatis wrote: post #7

I often wondered i could build some sort of general computing machine if we were pushed back to the dark ages or something. I guess you have to define exactly at what level of technological achievements we were pushed back to. But with the knowledge we have today, and without ICs (or advanced manufacturing facilities) and only "simple electronics" (whatever that would be) if this would be possible. Fun stuff to think…

In that case, if you want a somewhat entertaining very-high-level overview of what would need to be done, then there's a manga that showed this off a few chapters ago, it's called Dr. Stone. What stuck with me the most was that the purity needed for the silicon used in processors was absurdly high, so much so that they couldn't quite do that just yet, so they made a processor out of parametrons and used magnetic core…

Dr. Stone is great but I also found it to be a bit too hand-wavy. In real life you can't just build steam engines with a small village worth of labor + a "master craftsman". Mining, transporting, and refining iron ore alone is a huge task that could easily consume every drop of the village's labor resources and still not produce much iron. Fuel is also a huge task. Unless you have a high quality coal mine nearby, you have to create charcoal which is also very labor intensive (see: https://www.youtube.com/watch?v=GzLvqCTvOQY). I just can't fathom how Senku realistically makes processors unless he has a nation state worth of labor at his disposal.

But yeah, it is a fun "what if".

"What if a super genius with the entirety of wikipedia in his brain were sent back to the stone age? Could he rebuild modern society?"

Re: Megaprocessor – A micro-processor built large (2016)

#38

Post by dhosek »

TheOtherHobbes wrote: post #35
temeritatis wrote: post #7

I often wondered i could build some sort of general computing machine if we were pushed back to the dark ages or something. I guess you have to define exactly at what level of technological achievements we were pushed back to. But with the knowledge we have today, and without ICs (or advanced manufacturing facilities) and only "simple electronics" (whatever that would be) if this would be possible. Fun stuff to think…

First gen transistor computers often used standard functional units - gates, flip flops, and such - packaged into small modules with edge connectors and wired together with wire wrap on a backplane. Like this DEC PDP-8. http://www.oldcomputers.arcula.co.uk/files/images/pdp8104.jp... It's fairly easy to design a computer like this. Later TTL/CMOS designs replaced the packaged modules with much smaller 74xx/40xx ICs. Y…

We could use vacuum tubes instead of transistors.

(I googled this to make sure I wasn't misremembering what I read 40 years ago in an already outdated book at the library and I was suddenly filled with a sense memory of the smell of the interiors of old electric appliances loaded with tubes and dust.)

Re: Megaprocessor – A micro-processor built large (2016)

#40

Post by dhosek »

ezconnect wrote: post #32
temeritatis wrote: post #7

I often wondered i could build some sort of general computing machine if we were pushed back to the dark ages or something. I guess you have to define exactly at what level of technological achievements we were pushed back to. But with the knowledge we have today, and without ICs (or advanced manufacturing facilities) and only "simple electronics" (whatever that would be) if this would be possible. Fun stuff to think…

In the dark ages you can build gears. Gears can do arithmetic and calculus.

The catch is that there are tolerance issues. Doron Swade's account of building the two existing Difference Engine #2 models (http://www.amazon.com/exec/obidos/ASIN/0670910201/donhosek) is a good example of where the challenges lie. It was just barely possible to do with 19th century technology. Physical mechanisms deviate from theory by quite a bit.
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