Last year, I started to learn ZX81 assembly language programming. I was a teenager in 1982, when I got my first computer, a ZX81 with 16K extension memory (the original machine comes with 1K, 1024 bytes!). At that time, I was really a novice in computers, and assembly language seemed unreachable to me. In the course of 2016, I cam across games developed in assembly language by Bob, from Bob’s stuff. I was so impressed by what Bob managed to produce out of this little black box, extending its limits beyond what I thought was possible. This gave me the motivation to start learning Z80 assembly language. I’m still very much a beginner in a learning curve. Recently, Bob started a blog, teaching Z80 assembly language on the Spectrum. I’ve read a few articles already, and decided to adapt them to the ZX81. This will be the content of upcoming blog posts on this site.