Racing the Beam

This post is the fourth in a series looking at the design and implementation of my Glitch demo and the m4vgalib code that powers it.

In part three we took a deep dive into the STM32F407's internal architecture, and looked at how to sustain the high-bandwidth flow that we set up in part two.

Great, so we have pixels streaming from RAM at a predictable rate — but we don't have enough RAM to hold an entire frame's worth of 8-bit pixels! What to do?

Why, we generate the pixels as they're needed, of course! But that's easier said than done: generate them how, and from what?

In this article, I'll take a look at m4vgalib's answer to these questions: the rasterizer.


You can now view these demos in your browser!

m4vga is a technique/library for hacking the STM32F407 to generate high-quality analog color video signals with just a handful of resistors.

I wrote the C++ version between 2012 and 2015, and rewrote it in Rust in 2019 to put my money where my mouth is.

I did this because it was an immense technical challenge. Read on for details, including links to a series of blog posts I wrote examining the code in detail.