I find it amazing that men who created these things did it with slide rule and hand drawn schematics.
When we used to cut and paste we literally had to cut a circuit from one schematic that was a failure and paste it into a new Save to save time and not redraw the entire circuit.
You literally got out an exactly blade and cut and pasted.
Then We used white out LOL
Now everybody takes cut and paste for granted
The first computer I worked on was the size of a large kitchen table, it had to be programmed in binary with paper tape and could only add subtract divide and multiply.