Generator - Sega Genesis/Mega Drive Emulator

Generator is a Sega Genesis (Mega Drive) emulator featuring modern UI options, high-quality upscaling, and accurate emulation.

Quick Start

Build with Meson

# Install dependencies (Arch Linux)
sudo pacman -S meson ninja gtk4 libadwaita sdl3

# Install dependencies (Debian/Ubuntu)
sudo apt-get install meson ninja-build libgtk-4-dev libadwaita-1-dev libsdl3-dev

# Configure and build
meson setup build -Dui-backend=gtk4
meson compile -C build

# Run
./build/src/app/generator-gtk4 [rom-file.bin]

Console UI (no GTK required)

# Minimal dependencies
sudo pacman -S meson ninja sdl3  # Arch
sudo apt-get install meson ninja-build libsdl3-dev  # Debian/Ubuntu

# Build console version
meson setup build -Dui-backend=console
meson compile -C build

# Run
./build/src/app/generator-console [rom-file.bin]

A generator-headless binary is built alongside either UI backend and is used by the test/regression harness.

Build Options

UI Backends

• gtk4 - Modern GTK4/libadwaita interface (recommended, default)
• console - SDL3-based lightweight interface

Z80 Emulator

Single C++23 backend: kidoz/z80f, pulled in automatically as a Meson subproject (subprojects/z80f.wrap) and wired through src/cpu/z80/z80f/cpuz80-z80f.cpp. No build option to choose; nothing to install.

Build Examples

# GTK4 (recommended)
meson setup build -Dui-backend=gtk4

# Console (lightweight)
meson setup build -Dui-backend=console

# Release build (optimized)
meson setup build --buildtype=release -Dui-backend=gtk4

Dependencies

Required

• Meson >= 0.60.0
• Ninja build system
• GCC >= 13 or Clang >= 16 (C23 support required)
• SDL3 >= 3.0.0

GTK4 Backend (recommended)

• GTK4 >= 4.10.0
• libadwaita >= 1.4.0

Optional

• libjpeg - for JPEG screenshot support

Usage

# Run with ROM
./build/src/app/generator-gtk4 ~/roms/sonic.bin

# Run console version
./build/src/app/generator-console ~/roms/sonic.bin

Keyboard Shortcuts (GTK4)

• Ctrl+O - Open ROM
• Ctrl+L - Load State
• Ctrl+S - Save State
• F5 - Reset
• Space - Pause/Resume
• Ctrl+Q - Quit

Supported ROM Formats

• .bin - Raw binary ROM dumps
• .smd - Interleaved SMD format (auto-detected)
• .gen - Genesis ROM files
• .zip - Compressed ROMs (auto-extracts)

Features

• xBRZ Upscaling - High-quality pixel art upscaling (2x, 3x, 4x)
• Scale2x/3x/4x - Fast EPX-based upscaling algorithms
• Save States - Full save/load state support
• YM2612 + SN76496 - Accurate sound emulation

Architecture

CPU Emulation

• 68000: Two-stage code generation
  1. def68k reads instruction definitions from def68k.def
  2. gen68k generates 16 C files covering 64K instruction space
• Z80: z80f (C++23) via Meson subproject, bridged into the C codebase by a thin extern "C" adapter (src/cpu/z80/z80f/cpuz80-z80f.cpp).

Project Structure

generator/
├── include/
│   └── generator/  # Header files (shared across components)
├── src/
│   ├── core/       # Emulator core and context
│   ├── cpu/        # 68k and Z80 emulation
│   ├── audio/      # YM2612 + SN76496
│   ├── video/      # VDP and rendering helpers
│   ├── platform/   # SDL3 platform layer
│   ├── persist/    # Save states, AVI, patching
│   ├── ui/         # GTK4, console, headless
│   ├── xbrz/       # xBRZ image upscaler (C++23)
│   └── app/        # Entry point and event loop
└── meson.build    # Build configuration

Using Justfile

For convenience, a justfile is provided:

# Install just command runner
sudo pacman -S just  # Arch
sudo apt-get install just  # Debian/Ubuntu

# Build and run
just run-gtk4 /path/to/rom.bin
just run-console /path/to/rom.bin

# List all commands
just --list

Authors

Aleksandr Pavlov ckidoz@gmail.com

See AUTHORS.md for full attribution.

License

Generator is licensed under the GPL-2.0-or-later license. See LICENSE.