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Assuming one had access to old CPUs, ram, hard drives, and mainboards with I/O connections and BIOS chips and other chips in them.

I know the basics of the gates to make CPUs and RAM, and I know it's all very simple for the basic concepts. So assuming all of the advanced parts, like the chips were already available, how would one connect them to make an operable computer?

The purpose is empowerment by piecing together components to custom make laptops. The reason for asking this in 2022, is the proliferation of 3D printing and crafting, as well as the fact that technology that is several tech cycles old (6-10 years) is still very small and very powerful. Combined with the fact that the worst quality of parts in laptops are usually the case and motherboard.

Also if it is possible, are there open source solutions for making circuit boards?

JYelton
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Sophie McCarrell
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    What is your question? How to make a PCB at home? Today you can fairly easily get your PCBs manufactured for relatively low cost by sending them to one of the many rapid PCB prototyping manufacturers online – Eugene Sh. May 09 '22 at 19:49
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    Making PCBs at home is fairly common, but usually its cheaper and easier to just pay a prototyping service. Especially for small PCBs these can be very cheap. – user1850479 May 09 '22 at 20:01
  • Your title asks about building circuit boards, but the body of the question seems to be about assembling the boards with other components to make a complete system. Please clarify what you're really asking. – The Photon May 09 '22 at 20:21
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    PC MOBO's require many years experience. It's never cost-effect to DIY. You cannot compare a novice to a pro with 10 yrs experience in that field. THe PCB alone for 8 layers requires a 12 ton press. There are many steps in MOBO fabrication for PCB then PCA then ATE and self-test. – Tony Stewart EE75 May 09 '22 at 20:26
  • Haha i get burned by my flexibility, often, on stack exchange. I didn't know about businesses that prototype a pcb, that sounds like a great solution! I'd also like to know if there's a completely at home solution, but knowing about the prototyping manufacturers is very handy, so thank you! The person mentioning "pros" I've been a "professional" software dev for 15 years and something I make is much more likely to be performant and stable than a novice, but a novice can write code that does what a customer wants and they'll likely have some ideas that I won't have! – Sophie McCarrell May 13 '22 at 14:04

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Tape and etch resist pens for very simple stuff; iron-on for more complex designs. We have a Voltera for small-scale prototyping and production. The biggest thing you are going to run into is multiple layers; the most you can get realistically is 2-layer and most motherboards are pushing double-digits, probably more so on laptop boards. There's plenty of capable free/open-source CAD software out there.

vir
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  • Cool! Thanks for this. This is a good lead for me to do more reading! Maybe 2 layers would be enough for learning more about circuit boards. – Sophie McCarrell May 13 '22 at 14:08
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Assuming one had access to old cpus, ram, harddrives, and mainboards with io connections and bios chips and other chips in them.

Realistic scenario, many people have that lying around. If it still works as a PC, we call it an old computer, if it doesn't work, we call this electronic waste.

assuming all of the advanced parts, … were already available, how would one connect them to make an operable computer.

By building the same, very complex, boards computer manufacturers design and manufacture. Even the simplest 15 year old laptop motherboard takes person-months to design, build and test.

The purpose is empowerment by piecing together components to custom make laptops.

Then you'd need to design a laptop for exactly the parts you have. The prototype costs for that, the equipment to measure even oooooold laptop buses and the time designing this: orders of magnitudes more expensive than a new top-class laptop. And the design, prototype and measurement costs would re-occur for every single new old component you want to deal with.

By the way, honestly, someone who can take a bunch of hardware that's not documented and design a working computer out of it: That's not someone who's going to need much empowerment. That is an omniscient being who can look back in time and know how something works without any documentation ;)

But this all makes no sense: you have old hardware containing these components. That already works. So, keep that. If it doesn't work, it's broken, and the salvage, characterization, re-manufacturing (even if one had a design readily lying around, which nobody does!) costs are way more expensive than top-notch new laptops.

So, electronic waste.

if you're just concerned with how to physically make PCBs that you can use for computer hardware of the last 30 or so years: Not going to happen. You need multiple layers to get all the signals out of such high density components, you need very well-controlled sizes to achieve signal quality as necessary, and you need to have not a single error in tens of thousands of connections. That's why you need a PCB manufacturer; it's a high-precision, high-investment, high-expertise business building computer motherboards. That's not out of bad will or anything – it's just the result of the physics involved: compactness and the relatively high speed. If you want a computer at the functionality level of 1970s computers, OK, that's a different problem, but then, microcontroller boards that can do way more than these cost low single-digit Euros these days – there's nothing you can do to achieve anything similar at lower cost, or comparable performance.

Marcus Müller
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  • So there really isn't anything better than recycling? Which is costly, and terrible for the environment? Cars, clothing, mechanical parts, carpentry, etc. etc. it can be mended till the heat death of the universe.... but apparently not electronics? It just seems weird to have one single kind of thing be absolutely irreperable. – Sophie McCarrell May 13 '22 at 14:05
  • that's not at all what I wrote. I said you needed extensive equipment, knowledge, documentation that you probably don't have, AND that it's not economically feasible to repair such a thing. In which universe are cars and mechanical parts mendable ad infimuim? You need extensive knowledge to repair a modern car, and if a turbine part is worn out, it's irreparable. You're romantizing things! Many complex things are completely infeasible to repair. Car motors blocks, simple screws, the glass from your Ceran stovetop, lenses in camera, … – Marcus Müller May 13 '22 at 15:32
  • there's nothing "special" about electronics. It's just one of the fields where you get in contact with very technically complex things. If you dealt with e.g. airplanes on a daily basis instead of computers, you'd see the same about the more complex parts of these: while you can certainly (with *extensive* education) change things about the fuselage, I don't think you'll be able to mend a turbojet engine at home; to complex, specialized parts and materials with incredibly tight tolerances. And a turbojet engine and a laptop probably have a comparable number of individual parts. – Marcus Müller May 13 '22 at 15:36
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It used to be common for electronics hobbyists to make their own circuit boards. The equipment needed is essentially:-

  • Copper-clad boards. These are PCBs with a continuous layer of copper across the surface.
  • Etch-resist pens or sticky tapes.
  • Etching chemicals, bought as a concentrated liquid or crystals, which are then made up with water.
  • An etching tank and frame to hold the board being etched.

But it's pretty much impossible to do more than a 2-layer board like that. You could glue a stack of boards together, but the vias would be a problem.

So you may be able to make a computer using 1980's parts, but after that, you're going to need multi-layer boards.

Edit: If you wanted to make more than one board, then you could get specially coated boards with a photo-sensitive etch-resist layer. Draw the design on an acetate sheet with a marker pen, place the acetate on a blank board, and expose it to light.

Simon B
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  • I'm going to mark your answer as the solution for now. Maybe there's a more appropriate answer, but for now this and the other answer above create the picture i was looking for and gives me more leads to investigate in my endevour. – Sophie McCarrell May 13 '22 at 14:11