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Soviet computers are an interesting historical riff on this.

But I think this would be impossible to cut the cord completely, because a computer is basically a communication system (internally and networked) and by Conway's law groups zero in on comms systems that reflect their own dynamics, so as a civilizations we've built devices and networks that have zeroed in on our own internal dynamics. Therefore as a member of this civilization, you could not create something different. You'd need to go hang with some folks completely different until you absorbed that, then make it to reflect their dynamics. Uncontacted Amazon tribes? Dolphins? Elephants? Plants?