Street Fighter II on an E-Paper Sticky Note

How a Super Nintendo game went from slow motion to full speed on a tiny ESP32-S3 with an e-ink screen

In my last post I put a Game Boy on the Seeed SenseCraft Sticky, a sticky-note-sized gadget with an ESP32-S3 chip and an 800×480 black-and-white e-paper screen. Game Boy, then NES, then Game Gear all ran well.

So of course the next question was: what about the Super Nintendo?

The SNES is a much bigger machine. Two processors (one just for sound), fancy graphics modes, games up to 4 MB. I used a version of Snes9x, an emulator from 2005 that the Retro-Go project had already slimmed down for small chips. It compiled, Street Fighter II booted, the title screen appeared.

And it ran at 12 frames per second. A real SNES runs at 60. Ryu was punching in slow motion.

This post is how I got it to full speed, and then how I made the screen keep up.

Two different speeds

Before anything else, it helps to know there are two separate speeds on a device like…