Another example is mechanical parts and linkages. In the early 20th century there were many incredibly intricate mechanical devices -- the Curta calculator is a

Another example is mechanical parts and linkages. In the early 20th century there were many incredibly intricate mechanical devices -- the Curta calculator is an example[1] -- that have been replaced by semiconductors. I wonder if those could even be made today without having to recreate the knowledge and manufacturing processes. [1] https://calculating.files.wordpress.com/2012/02/curta-calculator-breakdown.jpg https://calculating.files.wordpress.com/2012/02/curta-calcul...