Turn Your ESP32 Into a Legendary MSX2+ Computer
Missed out on the legendary MSX? Now you can emulate the computer that gave birth to Metal Gear on an ESP32.
The Commodore 64, Apple II, Atari 8-bit line, and Tandy Color Computers are among the early personal computers that most people still remember today. The MSX line of computers, on the other hand, is something you might only be vaguely familiar with — unless you lived in Japan during the 1980s. There, MSX computers were very popular, and they are still favorites among enthusiasts.
Those who never had the pleasure of using an MSX really missed out. This relatively little-known machine is absolutely legendary for its gaming library. Japanese studios like Konami and Hudson Soft first developed games such as Metal Gear and Bomberman for MSX computers.
Unfortunately for those living in other regions who want to try out an MSX today, these machines are hard to come by. And there are also issues with different video and power standards to deal with. But now, thanks to Ivan Svarkovsky, anyone with an ESP32 board can run an emulated MSX2+. Called S3-MSX-PC, Svarkovsky’s emulator runs on bare metal on an ESP32-S3 and generates VGA video for an authentic experience.
Video output is generated using a resistor-based R-2R ladder connected directly to six GPIO pins on the ESP32-S3. This arrangement provides two bits of color depth for each RGB channel, producing a 64-color VGA display without the need for a dedicated graphics chip. Horizontal and vertical sync signals are also generated directly by the microcontroller, enabling compatibility with standard VGA monitors.
Instead of using an external sound processor, the emulator outputs pulse-density modulated audio signals that pass through an RC filter network. According to Svarkovsky, this produces clean stereo sound capable of reproducing both the square-wave PSG audio and FM synthesis music that defined the MSX era.
The ESP32-S3’s dual-core architecture was put to good use in this project. One core focuses on emulation tasks while the other handles video generation and audio output. Despite the limited hardware, the emulator supports demanding MSX2+ software, including games such as Metal Gear, Gradius, and Ys. It also includes advanced features like save states, support for up to 4 MB of mapped RAM, 256 KB of VRAM, Wi-Fi-based file management, and a “Smart Turbo” mode that accelerates CPU-intensive tasks while preserving timing-sensitive video and I/O operations.
As retro computing projects go, S3-MSX-PC is quite impressive. With little more than an ESP32-S3, a handful of resistors and capacitors, and a few connectors, it recreates an entire computing platform that introduced generations of players to some of the most influential games ever made. If you’ve got some free time next weekend, you won’t regret reproducing this build.