High school grad builds 8-bit computer from scratch

Don't forget that most people here are insanely brilliant and either work for Apple or Google and contributing to an Open Source project which implements VMWare In Node.js while planning their startup.

So the stuff this teenager hacked together is just a steady soldering hand and a lazy saturday afternoon.

"Wow, tough crowd here."

Yeah, no kidding. I just graduated from a computer engineering program and I still find this impressive, especially for a high school student. What could I do with a computer right out of high school? Code some java or c++ (poorly) and install linux on it? That's about it.

Did you watch the video? This is inspiring to me on many levels.

This probably earned him a salaried job at essentially any place he wants to work. Or at the very least an internship.

I hope he considers skipping college. There's no reason for him to be driven into ~$50k worth of debt, and I've certainly been happy with my decision not to go.

No, the processor appears to be constructed from 74LSxxx TTL logic chips. The memory is 2x32KB off-the-shelf SRAM units, but there comes a point where building things out of quad J-K flip-flops just becomes an exercise in patience and unnecessary spending. The registers are FFs, why make all of the memory that way? Just to say you did it? It doesn't add to the learning experience, just the drudgery.

It's still pretty impressive for a high school grad. Not to mention that he was able to code an OS and a few games.

You make a good point. I looked at his website, and it does not seem he designed it himself. If he did I would expect to see some gate level or even block level diagrams of the actual processor. Designing a processor from scratch is pretty challenging, if you do it you would want to show your work.

He only has TTL chip diagrams which do not show the internal architecture.

Regardless of how much he actually did, this is quite an accomplishment in modern-day America. Even the most basic attempts at some task slightly related to engineering should be lauded. They are very rare these days.

I think you guys should look a little closer before writing him off.

He pumped the OS in one bit at a time using DIP switches, wrote his own hex editor, and then wrote his own assembler and emulator, in javascript/canvas: http://web.mac.com/teisenmann/iWeb/adeptpage/adept_compiler....

The OS code is here: http://web.mac.com/teisenmann/iWeb/adeptpage/DUO_OS.txt

Run it through the emulator, it works.

Definitely not just a bit of light soldering...

I'm going to say "no", assuming that when you say "computer", you mean transistor-based.

I am not an expert on the subject, but I suspect making a facility that can manufacture thousands or millions of transistors, and then operating that facility would take obscenely more man-hours than one man has. Even if his goal was only a 4004, or even just a bunch of breadboards full of TO-92's.

Vacuum tube based might be possible for a very simple computer, if automating the glass-blowing and delicate assembly isn't too hard. After all, at least it's macro- rather than micro-!

Sure it is, but you have to define it better. He could build a difference engine much easier than he could build a system-on-chip. The difference engine would require metalworking and precision tools; the SoC would require a working digital computer to design, which requires lasers and other production technologies that in turn require advanced production technologies to make. Even if you just wanted to make a basic 4-bit machine with vacuum tubes, you'd still have to invent all of the preceding requisite technologies just to make the constituent components.

A mechanical device would be much easier, and would be well within the capability of a single person with all of the prerequisite knowledge to make. Just look at the Antikythera Mechanism.

Related: the Global Village Construction Set by Open Source Ecology (slightly confusing name IMO), a set of 50 machines supposed to bootstrap a small civilization. In other words, this is supposed to be enough to build your own computer, or mostly anything. (I won't say it is really enough, especially since most of those aren't even prototyped yet.)

http://opensourceecology.org/gvcs.php

I remember a "joke" mathematical recreation in Scientific American years ago (decades ago), where they describe a computer found in the jungle, operating with levers and ropes.

The mechanical-Turing-machine link http://hackaday.com/2011/03/25/mechanical-turing-machine-can... posted by chris11 is some kind of evidence here. I've also been thinking about this problem myself.

http://lists.canonical.org/pipermail/kragen-tol/2010-June/00... are some thoughts about possible low-tech digital logic techniques. https://github.com/kragen/calculusvaporis has some thoughts about how to build a reasonably practical non-bit-serial CPU out of only about 1000 NAND gates (or the equivalent.) I think that with the height-field approach described in the kragen-tol post, you could probably make it out of 1000 moving parts — although most of them would have to be machined to fairly tight tolerances. I think the level of mechanical difficulty is similar to a 1960s V6 engine (fewer parts, but much higher force and demands on precision), or a little higher than that of a Curta calculator (600 parts for Type I).

The Clock of the Long Now uses steel gears on stone and ceramic bearings. It contains some mechanical binary calculation (and the prototypes are the most beautiful machines I've ever seen) but it's not a programmable computer.

On that tangent: I've always wondered how things would have turned out if my parents had been savvy enough to provide me with the right book, when it turned out I couldn't understand enough of the English (not my native language) BASIC manual that came with my dad's first PC somewhere mid-to-end-eighties (when I was < 10).

However, I don't think any advantages in that regard detract from this achievement. Even if our parents had nudged us in the right direction, we may have been content doing many 'half' programs. Technical abilities are independent of the persistence required for a larger project such as this (or beginning a startup, for what that is concerned!).

You have to start somewhere, don't you think? He can't just start at the top and assume he knows how to build something. And there are certainly many lessons to be learned by building something that is already well understood (as many people seem to be attesting to in these comments). Consider it "practice before the big game," where "the big game" is hopefully something he does in ten years that makes people's lives a little better.

I think there's a lot of understanding to gain from building a computer from scratch. We've abstracted computing so much that starting over gives you a unique perspective on some of the big problems still out there, as well as a definite appreciation for the innovations we've come up with--even if it's nothing new.

Where is your computer?