I’ve been reading about early mechanical computing devices such as Babbage’s engines,

mechanical tabulators, and other gear‑based or punch‑card machines.

Modern computers, on the other hand, are fully electronic and based on binary logic,

transistors, and electrical signals.

But there seems to be a missing link in the evolution:

How exactly did computing transition from mechanical systems (gears, cams, levers,

punch cards) to digital electronic systems (vacuum tubes, logic gates, transistors)?

I’m trying to understand the actual "bridge" between the two worlds:

- What was the first step that converted mechanical operations into electrical signals?

- Did electromechanical relays serve as the intermediate technology?

- Were vacuum tubes the true turning point?

- Why did binary logic become the dominant model instead of mechanical decimal systems?

I’m looking for a technical explanation of the transitional phase — the piece of the

puzzle that connects mechanical computation to fully digital electronic computing.