While I have more than enough books on my “to read” list, I am always up for suggestions. “Code” came up in a Twitter conversations about computer hardware. I noted that one of my favourite courses from my Computer Science degree (in hindsight if not at the time) was where we went from “What is electricity?” right up to a pretty much fully working CPU. “Code” was recommended as it covers the same ground.

If you’d like to refresh your memory or you never took such a course, this is great introduction to how computers work.

It’s a book of two halves.

The first half starts with the foundations and principles. It starts with the concepts, like Morse Code, before building up from relays, to logic gates, to half-adders, to a complete, working CPU.

That bit is great. Clear steps and descriptions. I was reminded of many things that I first picked up at university and learned some details that I’d either completely forgotten or had never internalised at all.

After you get a working CPU the book largely turns into a history lessen, albeit from the year 2000. It talks about the rest of the computer but, out of necessity, in significantly less detail.

I found this second part to be weaker, though this may be because I’m coming at it from 2021 rather than 2000. These last sections have dated much more than the earlier, CPU-bound section and I wonder if the book had been about building just the CPU rather than the whole computer it would have dated better?

Having said all that, while weaker than the first half, it’s still well written and easy to understand.

Even if you skim the later sections, what quickly becomes apparent is that a computer has layer upon layer of abstractions. You may not understand every layer in the same amount of detail but knowing that they exist is, I think, useful as a software developer.

I can’t help but recommend this book to anyone interested in the subject.