[Michal Sapka] wanted to learn a new skill, so he decided on the Commodore 64 assembly language. We didn’t say he wanted to learn a new skill that might land him a job. But we get it and even applaud it. Especially since he’s written a multi-part post about what he’s doing and how you can do it, too. So far, there are four parts, and we’d bet there are more to come.

The series starts with the obligatory “hello world,” as well as some basic setup steps. By part 2, you are learning about registers and numbers. Part 3 covers some instructions, and by part 4, he finds that there are even more registers to contend with.

One of the great things about doing a project like this today is that you don’t have to have real hardware. Even if you want to eventually run on real hardware, you can edit in comfort, compile on a fast machine, and then debug and test on an emulator. [Michal] uses VICE.

The series is far from complete, and we hear part 5 will talk about branching, so this is a good time to catch up.

We love applying modern tools to old software development.

You want to learn assembly language. After all, understanding assembly unlocks the ability to understand what compilers are doing and it is especially important for time-critical code. But most tutorials are — well — boring. So you can print “Hello World” super fast. Who cares?

But decoding video data is something where assembly can really pay off, so why not study a real project like FFmpeg to see how they do things? Sounds like a pain, but thanks to the FFmpeg asm-lessons repository, it’s actually quite accessible.

According to the repo, you should already understand C — especially C pointers. They also expect you to understand some basic mathematics. Most of the FFmpeg code that uses assembly uses the single instruction multiple data (SIMD) opcodes. This allows you to do something like “add 5 to these 200 data items” very quickly compared to looping 200 times.

There are three lessons so far. Of course, some of the material is a little introductory, but they do jump in quickly to SIMD including upcoming instruction sets like AVX10 and older instructions like MMX and AVX512. It is no surprise that FFmpeg needs to understand all these variations since it runs on behalf of (their words) “billions of users.”

We enjoyed their link to a simplified instruction list. Not to mention the visual organizer for SIMD instructions.

The course’s goal is to prepare developers to contribute to FFmpeg. If you are more interested in using FFmpeg, you might enjoy this browser-based GUI. Then again, not all video playback needs high performance.