From an interesting book Chip War: The Fight for the World’s Most Critical Technology by Chris Miller.

Debugging:

Moreover, vacuum tubes made it possible for these digital computers to be reprogrammed. Mechanical gears such as those in a bombsight could only perform a single type of calculation because each knob was physically attached to levers and gears…However, the connections between vacuum tubes could be reorganized, enabling the computer to run different calculations.

This was a leap forward in computing–or it would have been, if not for the moths. Because vacuum tubes glowed like lightbulbs, they attracted insects, requiring regular “debugging” by their engineers.

Computer “chips”

Rather than a separate piece of silicon or germanium to build each transistor, he thought of assembling multiple components on the same piece of semiconductor material…Multiple transistors could be built into a single slab of silicon or germanium. [Jack] Kilby called his invention an integrated circuit but it became known colloquially as a “chip” because each integrated circuit was made from a piece of silicon chipped off a circular silicon wafer.

I am about a third of the way through the book and so far has been an interesting read.