Genesis Plus GX rendering Sega Genesis software

Regen’s Sega Genesis system context. This CC0 photograph shows a Sega Genesis console, the original hardware family represented by Regen’s Genesis and Mega Drive emulation. Source: Sega Genesis video game console (53665415899).jpg on Wikimedia Commons, by Chris Williams.

Regen

SEGA 8-BIT / 16-BIT EMULATOR

Regen

An accuracy-focused open-source emulator for Genesis and Mega Drive software, with deep support for Sega’s 8-bit systems and CD hardware through compatible frontends.

Jump to downloads ↓Jump to setup guide ↓

Genesis / Mega DrivePRIMARY SYSTEM

2000sPROJECT ROOTS

ActivePROJECT STATUS

WHY IT MATTERS

One accurate core across Sega hardware

Regen developed beyond a simple Genesis port into a careful multi-system core covering Mega Drive, Master System, Game Gear, SG-1000, and Sega CD compatibility.

BEST FOR

RetroArch and other frontends

It suits players who want a well-maintained Sega core in a frontend, with region options, controller support, save states, shaders, and a consistent library workflow.

Gameplay from Sonic the Hedgehog on Sega Genesis.

The people behind Regen

Built on Genesis Plus and expanded by Eke-Eke

The project began from Charles MacDonald’s Genesis Plus and was substantially enhanced by Eke-Eke. Its public source and credits document a long-running effort to improve accuracy, peripherals, console behavior, and portability.

Supported systems and capabilities

Genesis / Mega Drive, Master System, Game Gear, SG-1000, and Sega CD software.
Region, controller, video, audio, save-state, and display controls supplied by compatible frontends.
Open-source core available for use in projects and ports under its stated non-commercial license.

History and legacy

Regen is widely used as a reference-quality Sega 8-bit and 16-bit core. Its focus is not a single polished desktop application; it is portable emulation technology that frontends can expose on many platforms.

Download and availability

OFFICIAL SOURCE

Regen repository

The upstream repository provides source, documentation, release notes, and links to maintained ports.

View Regen on GitHub ↗

PROJECT STATUS

Core for compatible frontends

Best route: use a maintained frontend package for your platform.
Development: Active source project.
License: See the upstream project license.

Broken or missing download? Emulator projects move, archives disappear, and official links sometimes change. If this source no longer works—or you know a safer official source—please contact Retro Replay so we can verify and update it.

Regen setup guide

Setup note: Regen is usually installed as a core inside a frontend. Keep BIOS files, disc playlists, saves, and game files in clearly named folders before configuring the core.

Install Regen from your frontend’s core or package downloader.
Load one legally dumped Genesis or Mega Drive game and confirm the correct region.
Map a six-button controller layout if a game needs X, Y, and Z.
For Sega CD, follow your frontend’s documented BIOS and playlist requirements.
Use normal in-game saves first, then save states for temporary checkpoints.

ROM reminder: Regen does not include commercial games, Sega CD BIOS files, or copyrighted firmware. Retro Replay links to emulator software and documentation, not game collections.