The point here is that we don't need to build an iPhone, we only need a radio. Building a 8080 is much simpler, the USSR did it, the East Germany did it, China did it, all around the same time without too much difficulty. It's certainly would be much more difficult if the current civilization collapsed, but I think the author doesn't anticipate a total collapse, just a breakdown of the current economic system, thus it should be doable.
> Similarly the process for making a nuclear bomb can be written in a short paper, but few countries have successfully replicated it.
My understanding is that the physics of achieving the nuclear explosion itself is relatively straightforward. The real difficulties are to produce the weapon-grade materials needed, and to transform the explosion to an useful weapon, all under external sanctions, and even sabotage.
Taiwan had a nuclear weapon project in 1970s, significant progress was made in the beginning, if the U.S. didn't discover it and dismantle everything, it would be interesting to see how it turned out to be.
As the author themselves admits, this requires a very narrow band of Goldilocks catastrophe. Not catastrophic enough that you still have electricity, but catastrophic enough that all the plants on this list are destroyed or rendered unusable or embargoed from you? https://en.wikipedia.org/wiki/List_of_semiconductor_fabricat...
How is that going to work exactly?
No, it's a fantasy disaster, like Day of the Triffids and all the other John Wyndham style "cozy catastrophe" novels.
Real catastrophe is slow and grinding. Think "decline and fall of the Roman Empire" - a multi-lifetime process. Or something like Venezuela, where crumbling power infrastructure took out their aluminium smelter. This causes it to freeze solid and is unrecoverable without rebuilding the crucibles.
All the fabs on your list are fairly modern, and it is easy to see how they would be impossible to maintain in a Tainter-style collapse.
I would be looking into what you can do with ~1 um processes, which are currently accessible to amateurs. E.g. designs like https://news.ycombinator.com/item?id=11720289
Not sure about the Soviet Union, but East Germany had to "import" complete production lines from Western Germany in order to bootstrap their chip production. Of course the West prohibited exporting such sensible technology to the East, and there's some wild stories around involving the secret service, setting up a proxy chip manufacturing company in Western Germany, shutting this down, and "losing" the production lines, which showed up a few months later in East Germany.
But there will be plenty of Z80 and other 8-bit chips to scavenge after a civilizational collapse, and those chips are simple and slow enough to be used in computers built from breadboards and wires.
Some of the stories of how Western machinery was procured is mentioned from time to time in articles like this one:
It seems to have been less "broad sweep style" than I mentioned above though, more like that new products required specialized machines which were only produced by a handful Western manufacturers, and which were under the CoCom embargo. And the "grey-importing" of those machines went through various shadow companies in different countries to cover everything up.