A middleware system for a Raspberry Pi 5 based 86Box Win95/i486 emulation appliance. Bridges the 86Box emulator (via its unix socket control interface) with physical hardware — status LEDs and NFC-based disc swapping — through an ESP32-C6 microcontroller.

Async bridge between the 86Box unix control socket and a serial-connected ESP32-C6.

• Forwards !led and !media status events from 86Box to serial for LED control
• Receives fddload/cdload/fddeject/cdeject mount commands from serial (NFC tag reads) and relays them to 86Box with an optional path prefix
• Optionally polls screencrc and sends exit when the screen matches a target CRC + dimensions (for auto-shutdown when the emulated OS has shut down)
• Reconnects automatically when 86Box restarts

pi486 --socket /tmp/86box.sock \
      --serial /dev/ttyAMA0 \
      --fdd-prefix /mnt/floppy/ \
      --cd-prefix /mnt/cdrom/ \
      --screencrc "27CDAD2E 656 416"

Connects to the Pi via 3.3V TTL UART on GPIO 14/15. Drives status LEDs and reads NFC tags.

• LEDs: Power, HDD, Floppy, CD, Network — driven by !led events from serial
• NFC reader: PN532 over I2C, polls NTAG215 tags every 500ms
• Tag insert: Reads tag data, sends fddload/cdload command over UART
• Tag removal: 2 consecutive missed polls (~1s) triggers fddeject/cdeject

USB-connected NFC tag writer. Accepts commands over USB serial:

Browser-based UI using the Web Serial API to communicate with the writer ESP32. Built with TypeScript, Vite, React, TailwindCSS, and shadcn/ui components. Requires Chrome/Edge.

NTAG215 tags (504 bytes). Simple text format:

<type>:<write_protect>:<path>

Examples:

• F:0:Win95Boot.img → fddload 0 /mnt/floppy/Win95Boot.img 0
• C:0:Quake.iso → cdload 0 /mnt/cdrom/Quake.iso

pi486/
├── Cargo.toml
├── flake.nix                       # Nix dev shell
├── src/
│   ├── main.rs                     # CLI, entry point
│   ├── bridge.rs                   # Socket ↔ serial event loop
│   ├── protocol.rs                 # Command parsing, path prefix, screencrc
│   ├── serial.rs                   # Serial port / stdio abstraction
│   └── socket.rs                   # Unix socket connection + reconnect
├── esp32-appliance/
│   └── esp32-appliance.ino         # Appliance firmware (LEDs + NFC reader)
├── esp32-writer/
│   └── esp32-writer.ino            # Writer firmware (USB serial + NFC writer)
└── writer-ui/                      # Web UI (Vite + React + TypeScript)
    ├── src/
    │   ├── App.tsx
    │   ├── lib/serial.ts           # Web Serial API abstraction
    │   └── components/ui/          # shadcn-style components
    └── package.json

cargo build --release

cd writer-ui
npm install
npm run build

Open esp32-appliance/esp32-appliance.ino or esp32-writer/esp32-writer.ino in the Arduino IDE with ESP32-C6 board support installed. Requires the Adafruit_PN532 library.

With Nix:

nix develop

This provides Rust toolchain, Node.js, and Arduino CLI in a single shell.