The answer doesn’t actually lay out how electricity flowing through a bunch of NAND gates physically causes the computer/CPU to begin booting up.<p>There’s always a step missing in these types of answers,<p>step n: electricity begins to flow through gates<p>step n+1: ???<p>step n+2: Microcode execution begins<p>Presumably in step n+1 something happens to the chip, more than just heating it up, that causes a regular pattern which we would call the very first step of microcode booting up.