Gates, Transistors, Silicon

When somebody asks me which book to read to really understand how a computer works I point him or her to the must read book on the topic ‘But How Do It Know‘. If after reading they come back and ask how such a computer actually ends up in chips here are my next suggestions for them:

‘But How Do I Know’ starts its journey from logic gates and does not explain, on purpose, how a gate is actually constructed. It’s not strictly necessary to understand this to understand computers but from a vertical point of view it’s good to understand that part as well. So here we go with my suggestions:

First one should understand how transistors work. A good resource for understanding this, even without a physics background is this great video on YouTube. After 5 minutes you understand the concept of a semiconductor and how a transistor is constructed on a microchip.

Next, this knowledge can be used to understand how transistors form a gate. Wikipedia has a good page on NOR gates and how they are built with two or four transistors.

The next step is to take a closer look at how a transistor is implemented on a silicon die of a real chip. For this I can recommend this great article on a tear down of a 555 timer chip by Ken Shirriff.

Obviously the transistors in the 555 timer chip are huge compared to the billions of transistors on a single processor chip today. To understand the challenges of making them ever smaller I found this article about the status of Moore’s law in the IEEE spectrum magazine very helpful.