Ask HN: Help finding a programming primer posted on HN several years ago?

A few years ago I came across a website that explained computers and programming starting with binary. It was a black and white, almost text-only website with about 100 pages. It did a great job of explaining every abstraction layer in very clear, basic terms. I thought it would be a perfect starting point for my kids. Sadly, I lost the link. I’ve spent hours looking for it.

Does anyone remember what I’m talking about?