MSXnano is an open-source MSX2+ FPGA implementation for the Tang Nano 20K (Gowin GW2AR-18). It runs a complete MSX2+ system — Z80 CPU, V9958 VDP with HDMI output, SCC/OPLL sound, SD card with Nextor, USB keyboard, joystick and mouse, and optional WiFi — entirely on the FPGA, with no original MSX hardware required.
📖 Project page, install guides and community: msx.barcelona
- Z80 with authentic MSX timing (per-M1 wait state, ~100% of real MSX speed)
- V9958 VDP with HDMI output
- MSX2+ BIOS · 4 MB mapper · 2 MB Megaram SCC · RTC
- PSG · OPLL · SCC+ (×2) · stereo
- SD card with Nextor 2.1.4, boot menu and file browser
- USB keyboard, joystick and MSX mouse through an RP2040 companion
- Turbo — Panasonic WSX protocol at an exact 5.369318 MHz
- Optional WiFi (MSX UNAPI) via ESP-01S, or an ESP32-C6 that adds a status screen
There used to be two BIOS builds — one that booted straight to MSX, one with the SD
browser — so you had to pick which one to flash. There is now a single BIOS and the
menu is a setting: press S at boot, tick Menu al arrancar, Save & Restart.
Untick it and you are back to booting straight into MSX. The choice is stored in flash.
With WiFi connected, press F in the browser to search and download ROMs and disk images straight to the SD card, without a PC.
The onboard BL616 is no longer used. USB keyboard, joystick and mouse are now served by an RP2040 (Pico Zero) over a single wire.
This removes the biggest compatibility headache of the previous versions: Tang Nano 20K
boards made since 2024 (marked 3921) ship a BL616 in a secure-boot state that often
could not run the companion firmware, leaving you without a keyboard and needing an
external M0S Dock. With the RP2040 that problem is gone — every board behaves the same.
And it adds what the BL616 never did: a real MSX mouse, from any USB mouse.
Alongside WiFi you can fit an ESP32-C6 with a 240×240 LCD that shows connection status, the clock and whether Turbo is on — plus the classic MSX boot logo. The ESP-01S is still supported if you only want WiFi.
All three companions are optional and independent. The core boots and runs with none of them (you just get no keyboard, so fit the RP2040 at least).
| Pico Zero | Tang Nano 20K | Notes |
|---|---|---|
| GP15 (TX) | pin 31 | PIO-UART, 115200 8N1 |
| GND | GND | common ground |
| VBUS | 5V | powers the Pico |
Plug the USB keyboard, gamepad or mouse into the Pico's own USB port (a hub works).
Firmware: rp2040_keyboard.uf2 for the Waveshare RP2040-Zero (the default), or
rp2040_keyboard_pico.uf2 for a plain Raspberry Pi Pico. Both are in
fpga/rp2040/, source included.
| ESP-01S | Tang Nano 20K |
|---|---|
| RX | pin 27 |
| TX | pin 28 |
| VCC | 3.3V |
| GND | GND |
The C6 replaces the ESP-01S on the same UART and adds one wire for the Turbo indicator.
| ESP32-C6 | Tang Nano 20K | Signal |
|---|---|---|
| GPIO17 (RX) | pin 27 | FPGA → C6 |
| GPIO16 (TX) | pin 28 | C6 → FPGA |
| GPIO3 | pin 29 | Turbo status |
| GND | GND | common ground |
Board: Waveshare ESP32-C6-LCD-1.3. Firmware: ESP32-for-FPGA.
| Step | File | Address | Tool |
|---|---|---|---|
| 1 | msxnano.fs |
0x000000 |
Gowin Programmer — External Flash mode |
| 2 | BIOS pack | 0x200000 |
Gowin Programmer — exFlash C Bin Erase, Program thru GAO-Bridge |
| 3 | fpga/rp2040/rp2040_keyboard.uf2 |
— | Drag onto the Pico's RPI-RP2 drive (hold BOOTSEL while plugging in) |
| 4 | ESP-01S or ESP32-C6 firmware | — | Only if you fit one |
The BIOS pack contains copyrighted MSX system ROMs, so it is not distributed here — build it from your own dumps. It bundles the MSX2+ BIOS, sub-ROM, Nextor 2.1.4, the WiFi ROM, the boot menu and the config block.
| MSX key | USB key |
|---|---|
| GRAPH | Left Alt, or either Windows key |
| CODE / KANA | Right Alt |
| STOP | F12, or Scroll Lock |
| SELECT | End |
| CAPS | Caps Lock |
| F6–F10 | F6–F10 — sent as SHIFT+F1..F5, exactly as on a real MSX |
| F1–F5, arrows, HOME/INS/DEL, ESC/TAB/BS/RETURN | 1:1 |
Turbo is not a key: it is set from Settings (Boot Turbo) or by software through the
Panasonic ports $40/$41.
The layout is fixed by design: Megaram in slot 2, SD in 3-2. SofaRun detects the Megaram automatically; other software may need it set by hand.
The 3D case is based on this Thingiverse design, which served as the inspiration and starting point for our improved version.
This project is based on the work of jabadiagm (MSXgoauldSD_tn20k), licensed under GPLv3.
It is a standalone FPGA implementation that does not rely on the original physical MSX hardware, so all hardware-related files (PCB, MSX interface, schematics) have been removed.
Claude (Anthropic) collaborated on this project.
- 🌐 Project page & guides: msx.barcelona
- 🐙 Other MSX FPGA projects: github.com/Papipapito
- 🗣️ Barcelona MSX community: AAMSX