Glass memory?

From: "steven--- via cctech" <cctech at classiccmp.org> Paul and others said What if you can't make ICs any more? Or rather, what level of IC fabrication would it be possible to construct from scratch? For semiconductors, you'd start with machinery to make ultra-pure materials (silicon, I'd assume). A Czochralski crystal growing machine to make the cylinders of pure mono-crystal silicon from which wafers are sliced. Polishing machinery. Wafer coating machines. Wafer steppers. Etching, metal coating, diffusion, etc......... most of which also require very pure and often exotic ingredients. (I remember being amazed to read that chlorine trifluoride is used as a cleaner in the semiconductor industry. Look up the properties of that compound, it will blow your mind.) Which brings to mind the amazing work of Sam Zeloof: https://www.youtube.com/results?search_query=zeloof+z1+chip <https://www.youtube.com/results?search_query=zeloof+z1+chip> It really depends on how "from scratch" we have to go. In a more real world scenario where the ability to make large, low density MSI chips in the micrometer scale is somehow lost through scrapping and ignorance, recreating the machines required to make them on an industrial scale shouldn't cost a huge amount. It's proof, that if someone can make these chips in his garage on a shoestring budget, a few hundred grand should be able to recreate the technology in order to reproduce them industrially. Obviously there'd be an iterative process, much like happened in history, to shrink the die process if you were indeed trying to get smaller. However, if we had some sort of massive scale Carrington event (or larger) that fried every IC ever made, things would definitely take a step back. I imagine that the large crystal-growing tanks themselves would be fine, but the control gear etc would be truly sent back to the dark ages. It might take 5 years or more to re-engineer all the control gear to work in an electricity-free (or at least IC free) world, with many other things like food, water and fuel supplies taking precedence. Then there's the task of re-engineering the IC production from paper copies of research papers and documentation (no internet, remember), which could prove rather difficult to duplicate and distribute without photocopiers. We'd essentially be taken back to the early 60's when it came to IC production, having to re-engineer everything from scratch. Much of the non-electronic machinery and R&D would still be available, so i imagine getting back to where we are now would only take 20 or 30 years, instead of 60, but it would still be a long and iterative process which would be likely hampered by the whole "end-of-the-world Armageddon" thing the Carrington-scale event would have caused. I imagine most people would be worried about putting food in their bellies and keeping warm, rather than worrying about getting their Exchange server working. I think i may have overthought this. Josh Rice