It would have been better if they looked for the densest circle with an area of 1 square km. Although a square shaped area has its tangible benefits - you "feel" population density more when it’s on your own street obviously, and since square areas provide more information along a few axes (the ones containing the corners), you can get an idea of the population density in an area by placing a square’s corners on the street. A square is probably not the best shape for this, though.
I don’t save articles often, but maybe one time in a few months I see something I know I will enjoy reading again even after 1 or 2 years. Keep up the great work OP!
It’s a thoroughly interesting video, but I’m a bit disappointed he never took his idea any further than he did. I’d really love to see something like a 6502 being made at home.
You say ex AMD like that's all he's known for. Jim Keller is like some fairy who flies around companies designing sota chips.
From DEC, to AMD, to ARM and Broadcom, his own firm, hops over to Apple which then buys his old firm, heads back to ARM and then over to Tesla and finally one last stop at Intel before going into startup land again.
Worked on the K7/K8, MIPs for networking, did the A4 and A5 for Apple, on the Zen/K12, and the Tesla TPU.
That's good for him, but it means we'll never find out in the near future whether it's possible for the average person to create useful ICs in their garage.
From a business perspective, I agree that it’s a fool’s errand. But imagine being able to design and tangibly build your own computer, at home. 6400 euros is pennies for a business, but exorbitant for an individual.
I believe the way Sam Zeloof circumvents the enormous amount of capital needed for a chip fab by relying on modern technology to create 1970’s technology. He simply mounts a cheap digital projector onto a cheap microscope - they didn’t have that advantage in the 70s, and thus it cost millions to start a chip fab. My point is that it could conceivably be doable for an individual to create old computing technology with the advantages of living in the modern world. I certainly don’t have the drive to do it, but I wish someone did.
You'd spend far more than 6400 euros to do it at home.
If you did it often and didn't count your own labor costs, then maybe the average cost would be less, but that's an incredibly specific situation.
> I believe the way Sam Zeloof circumvents the enormous amount of capital needed for a chip fab by relying on modern technology to create 1970’s technology
Yes, exactly.
Old lithographic technology is so crude that you can even use modern high resolution laserjets to print masks (10000 dpi is less than 3 microns).
Even so, 1970s-era CVD, PVD, and plasma etch is still quite complicated, and CMP is impossible (it hadn't even been invented yet). So the devices you can create are significantly integration-constrained.
Do you have examples for models of laser printers can actually achieve a resolution of 10000dpi? It doesn't need to be office equipment. Any example would suffice as I so far thought that laser printouts were limited to a maximum resolution between 1200 and 2400dpi.
Not at home, but at professional printing houses absolutely.
This isn't hypothetical, I've done it -- in grad school we would send out (I believe) 30000 dpi print jobs on transparent polyester film, and then adhere those to glass blanks to create cheap masks for MEMS fabrication. We had an old Canon i-line lithographic aligner that accepted the glass blanks.
I think the print jobs cost us about $100 each.
Here's the first Google result for a vendor (I don't remember who we used). There's a price list on their page and it looks like they have capability up to 50,800 dpi.
Maybe a little different. For narrow enough definitions of "clothing," homemade clothing can be good. And there are other artisanal homemade crafts (e.g. woodworking) that can be good. But I agree in general.
Industrially (by which I mean how it was done circa 1970), silicon oxide and silicon nitride was etched using a buffered HF solution known as BOE (buffered oxide etchant). The buffer was typically ammonium fluoride; because of the presence of the buffer, the concentration of fluorine ions in solution stays constant even as some of the fluorine attacks the substrate to form e.g. hexafluorosilicic acid. Since the concentration of fluorine stays constant, so does the etch rate.
If you just pull some rust cleaner off the shelf at home depot, the etch rate will crash as the concentration of fluorine ions decreases. That's compounded by the fact that the HF concentration isn't very high in the first place.
As a result it would be very difficult to determine how long your wafer should remain in the etch bath. Underetching could easily cause "opens" in the circuits from unremoved insulator, and overetching and/or undercut can destroy the patterns you're trying to produce. Either way it can ruin the chip.
Yep, he used an ammonium fluoride buffer.
> Instead of a standard HF etch, a buffered oxide etch of NH4F (Ammonium Fluoride) in HF can be used to control the etch rate and photoresist lifting. I use approximately 20-30g of 100% NH4F per 50mL of HF (stock whink rust remover)
Ammonium fluoride definitely isn’t as easily accessible as rust cleaner, but you could buy it for a somewhat cheap price on Amazon.
There's a section of one of the Diary of a Wimpy Kid books that talks about this exact thing. I was reminded of it as soon as I saw the headline. The justification is comes up with is that kids with names at the front of the alphabet sit in the front of the classroom, so they get called on and learn more. It definitely turned some gears in my brain when I first read it as a teen. Here's the relevant page: https://imgur.com/a/6wIx6qg
If you think about it, there are about a couple of hundred super-centenarians (110 or older) alive[1]. Surely at least one of them met a very old relative when they were young - for example, when I was 9, I met a great uncle who was 100 years old. Taking into account life expectancy, if you assume at least one of them has met someone 85 years older than them, that means this oldest "directly known person" would have been born at least 195 years ago (1829). Which means there’s a good chance someone alive has met someone born in the 1820’s.
I know you’re not allowed to say this, but I’m not sure many people here actually read the article. Many people are responding to the argument itself in ways that were already addressed in the article (for example, there’s a whole section outlining two rebuttals to the “perfect island” parody).
I dunno, for some reason I found the first 30 minutes or so excruciatingly dull and just didn’t care about where it was going. I really enjoyed Nanook, so was surprised. Possibly I just wasn’t in the right mood for it.
[edit] and The Last Laugh, and Sunrise, though I was less enamored of Nosferatu than I expected to be. Enjoyed those too, to connect it to Murnau as well as Flaherty.
It’s always neat when you think of some historical figure as ancient then see a video of them right in front of you, like history is not as far away as you thought. Similar to how there’s a recording of Johannnes Brahms (https://youtube.com/watch?v=0d848uKtdsA), and a video of the funeral of the last veteran of the war of 1812: https://youtube.com/watch?v=eMlKtfBHiAQ
