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Making RAM at Home [video]

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Re: Making RAM at Home [video]

#51

Earlier quoted context omitted.

Admit it, deep down, our inner engeering child also wants to build a semiconductor clean room ;)

I do but my days in the fab taught me that you do NOT want people to do this, considering the extremely dangerous chemicals involved. People have died changing EMPTY tanks of phosphine gas used for doping… and HF acid used for etch is another nightmare entirely.

Knowing that really helps you understand just how valuable semiconductors are as a product.

Re: Making RAM at Home [video]

#52
Technologies that were considered "high-tech" 20-30 years ago are now accessible to regular people. Making DRAM. I remember a video recently of a guy making his own floppy disks. Next I expect people to manufacture integrated circuits that have been discontinued. Like the Z80

Re: Making RAM at Home [video]

#53

So, I get that we charge the capacitor up, and that it leaks so we must recharge it periodically. I don't get two things: 1. How is the value read? Is it reading the leak? 2. How is recharging done? I guess the leak itself (assuming my guess in 1. holds) could provide charge for some logic that checks "if has charge then recharge else nop". I still don't really get transistors :P, but this was cool.

You measure the charge (if it is there) before it is completely gone (if it were ever there). Capacitors always leak, these capacitors leak fast.

Measuring the charge also removes some of the charge -- fast, compared to the leak spead.

DRAM chips have a circuit that writes the value back -- charges the capacitor up if there's supposed to be a charge, drains it if there's not supposed to be a charge.

Refreshes and normal reads are the same, except that normal reads sends the value(s) to the output pin(s) on the chip.

He has "only" shown the basic grid of capacitors and transistors. The chip he shown has no circuit to measure charges or to write them back afterwards. This makes it easier to test the basic grip and the basic capcacitors.

Pretty sure the proper read out and write back circuit comes in the next video.

Re: Making RAM at Home [video]

#54
post #5

I saw this video yesterday and considered posting it, but I wasn’t sure if it was appropriate for HN. This channel has another video where it shows how the clean room lab is created starting from a basic backyard shed, and that was truly astounding. The positive pressure to keep the number of particles low in someone’s backyard is almost mystical to me.

You’re not sure if someone building a RAM clean room in a shed is appropriate for HackerNews, literally “news for nerds”? A dictionary purchase may be warranted

There's no mention of AGI, climate change, AWS outages, Trump, crypto schadenfreude or my new MVP that you should totally sign up for even though I just vibe coded it 20 minutes ago and the DNS hasn't fully propagated yet, but the API is amazing plz like comment and subscribe.

Ok, maybe I'm being a bit cynical. Stories about bikeable cities are welcome too. And wasn't Soylent popular for a hot minute back in the day?

Re: Making RAM at Home [video]

#55

This is incredible! 1100 degrees in your backyard shed! And the video explains it well too

The furnace is a low cost off-the-shelf Chinese product from Anhui Beq Equipment Technology Co.

Much more impressive are the modifications to the microscope, transforming it into an improvised lithography machine, and the home made plasma etching machine, cobbled together from surplus components.

Of course, the whole thing, starting from the clean room, is extremely impressive -- Intel started their business in a much simpler facility.

Re: Making RAM at Home [video]

#58
post #12

Earlier quoted context omitted.

If you haven't seen this one, I highly recommend it: Indistinguishable From Magic: Manufacturing Modern Computer Chips https://www.youtube.com/watch?v=NGFhc8R_uO4&t=2070s It's quite old but I think there is no modern version of it. I've tried posting to HN a few times but it hasn't gained traction for some reason, but I find it absolutely mind blowing.

Videos in general don’t get much traction here. Most of the time I don’t want to watch them in this context either, when other sites I do. Maybe it’s just I come here for the old web feel when video was costly, rare and short.

Which is a pity, because lots of videos really need to be seen to be fully appreciated. Especially the ones showing stuff being made. And the ones that tend to show up here are usually worth the time.

I'm totally with the text folks on the 5 hour Fossdem sessions, though. Give me an accurate transcript I can grep or don't even bother.

Re: Making RAM at Home [video]

#59
post #2

I wasn't expecting what the inside of the shed would be like!

There's another video on YouTube by the same guy detailing how he built his backyard clean room shed. I was kind of surprised at how easy it was - it's definitely a construction project that requires some specialized knowledge, but the fact that it's tractable at all for one person with a shed is pretty amazing to me.

Of course it not easy. He spent $20k on materials and a good amount of elbow grease just to construct this one room. In order to maintain the clean environment the air circulation runs 24/7 and he washes all the surfaces daily using cleanroom wipes. Deionized water system provides water for washing the cleanroom gowns. It is a lot of work just to have a small facility at home for odd jobs.
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