Sega Genesis emulators

Sega Genesis / Mega Drive

Top: PAL Sega Mega Drive. Middle: Sega Genesis Model 2 with 6-button controller. Bottom: Sega Genesis Nomad, portable variation.
Developer	Sega
Type	Home video game console
Generation	Fourth generation
Release date	1988
Discontinued	1997
Predecessor	Master System
Successor	Saturn
Emulated	✓

The Sega Genesis is a 16-bit, fourth-generation console released by Sega in Japan on October 29, 1988 and in the US on August 14, 1989, where it retailed for $189.99. It had a Motorola 68000 CPU at 7.6 MHz and a Zilog Z80 at 3.58 MHz. In other regions, it was known as the Mega Drive. It had several add-ons, including the Sega CD (a CD add-on, called Mega CD outside America) and the 32X (a 32-bit, cartridge-based add-on).

The Sega CD was released on October 15, 1992, and retailed for $299.99 and had a Motorola 68000 CPU at 12.5 MHz and 64 kbit of RAM. The Sega 32X was released on November 21, 1994 for $159.99. It had 2 SH-2 RISC CPUs at 23 MHz with 256KB of RAM and 256KB of VRAM.

Genesis emulation is very good, with a high degree of game compatibility (many of them claim nearly 100% compatibility with commercial games, including Virtua Racing). They are available on many platforms. Many Genesis emulators also feature compatibility with the Sega Master System (SMS), and the Game Gear (GG) as well as earlier Sega consoles. However, genesis-based arcade boards and the Sega Pico are still sketchy.

Emulators

Name	Platform(s)	Latest version	Hardware features and accessories	Hardware variations	Enhancements	FLOSS	Active	Recommended
PC / x86
BlastEm		Nightly builds libretro core 0.6.2	~	✗	~	✓	✓	✓
Genesis Plus GX		libretro core Cyclone libretro core	~	✗	~	NC	✓	✓
PicoDrive		libretro core 1.93	~	✗	~	NC	✓	✓
ares		git Artifacts v138	~	✗	~	✓	✓	✓
BizHawk		Dev builds 2.9.1	~	✗	~	✓	✓	~
MAME		git artifacts 0.265 libretro core	~	✓	~	✓	✓	~
Kega Fusion		3.64	~	✗	~	✗	✗	~
Mednafen		1.32.1	?	✗	~*	✓	✓	✗
Exodus		2.1	?	✗	✗	✓	✗	✗
GENS Gens GS/II		r7 (Gens/GS) git (Gens/GS II) 2.14	~	✗	~*	✓	✗	✗
higan		v110	~	✗	?	✓	✗	✗
FinalBurn Neo		Stable WIP builds libretro core	~	~	~	NC	✓	✗
DGen		1.33	✗	✗	✗	✓	✗	✗
Genecyst		x.xx	✗	✗	✗	✗	✗	✗
KGen/KGen98		034b 9804	✗	✗	✗	✗	✗	✗
Megado		git	✗	✗	✗	?	✗	✗
Regen		0.972	✗	✗	✗	?	✗	✗
Nuked-MD		git	✗	✗	✗	✓	✓	✗
Mobile / ARM
Genesis Plus GX		libretro core	~	✗	~	NC	✓	✓
MD.emu		1.5.77 (Android) 1.5.46.02 Pyra	~	✗	?	✗	✓	✓
PicoDrive		1.93 libretro core	~	✗	~	NC*	✓	✓
FinalBurn Neo		libretro core	~	~	~	NC	✓	✗
Consoles
Nintendo Switch Online (m2engage)		N/A	✗	✗	✗	✗	✓	✓
3D Classics (m2engage)		N/A	✗	✗	~*	✗	✗	✓
NeoGenesis		V25	~	✗	✗	?	✗	✓
Genesis Plus GX		1.18.0 git 1.7.5 RC1 RetroArch 360 0.9.8.3 1.2	~	✗	~	NC	✓	✓
PicoDrive		1.18.0 1.93 PicoDrive 1.51b	~	✗	~	NC*	✓	✓
jEnesisDS		v0.7.4	✗	✗	✗	✗	✗	✓
Virtual Console		N/A	✗	✗	✗	✗	✗	✓
PGEN		git	✗	✗	✗	?	~	✓
Sega Genesis Plus		Libxenon	✗	✗	✗	?	✗	✗

Comparisons

BlastEm

Aims for cycle accuracy but unlike Exodus, aims for lower system requirements and has substantially higher compatibility. Latest stable release is quite old, use nightly or libretro core. The "Nuked" core that can be optionally used in Genesis Plus GX provides more accurate FM emulation than what's in BlastEm at present but BlastEm's own implementation is solid too and differences are mostly inaudible. Both are way better than the widely used old MAME emulation, which is the default option on Genesis Plus GX too because it's fast.

Genesis Plus GX

A solid emulator for the Sega Genesis / Sega Master System / Sega CD / Game Gear. The only things it lacks are 32X and Pico support, and a native desktop port. The only way to get this emulator on the desktop is to use the libretro core, which allows for all the benefits of RetroArch like EmuVR support, shaders, dynamic sync, and other enhancements. The version used in BizHawk adds features for speedrunners but only the version used in RetroArch supports Nuked OPN2 cycle-accurate Yamaha YM3438(YM2612).

Genesis Plus GX Wide

Custom fork of Genesis Plus GX available as a libretro core, it includes experimental widescreen options. Sega CD/Mega CD games are currently unsupported.

Genesis Plus GX-Cyclone

Custom fork of Genesis Plus GX available as a libretro core, it includes support for games with enhanced graphics designed for the Firecore system-on-a-chip made by Digital Media Cartridge Ltd.

PicoDrive

Strongly prioritizes performance over accuracy. Compatibility and accuracy aren't as good as Genesis Plus GX but it's useful on very underpowered systems like the Raspberry Pi Zero. Currently the first and only cross-platform option for Pico games. Libretro and BizHawk versions don't have a stylus or turn page support, while the obsolete standalone version does.

higan / ares

Also developing cycle-accurate Genesis emulation, akin to its own SNES emulator core. v130 version brings "YM2612 improvement" and support for "Mega Mouse". v131 version of ares boasts 95% compatibility with 32X games, while there are still minor glitches, this is leaps and bounds better than other emulators as of late December 2022. v132 version of ares brings every single Sega Mega CD game at least boots; with an estimated 86% of the library playable to completion.

BizHawk

"Just works out of the box" solution for Genesis/Mega Drive, CD & 32X, bundled with two cores (Genplus-GX/Genesis Plus GX without Nuked OPN2 support and PicoDrive), ensuring both excellent compatibility and good speed.

Kega Fusion

The project of an employee with previous experience at Sega. Kega Fusion has high compatibility, is easy to use, and has plugin-based filter support but it is no longer updated. It has been surpassed by better emulators and also has some issues on newer versions of Windows which can be solved with compatibility settings.

Exodus

Exodus is one of the first emulator achieved cycle accuracy at the high cost of system requirements, but it is no longer updated and far from complete. It is still somewhat useful as a reference for the Genesis hardware, but users will have a faster and more accurate experience with BlastEm or other recommended emulators for Genesis.

Regen

A focus on accuracy has earned its high compatibility with games, but it does not emulate the Sega CD and 32X. It also allows overclocking.

MAME

Runs most games fine. Some don't work that well, but it's got about a 95% compatibility rate. Almost all of the C/C-2 arcade games work well in MAME - only the Print Club games don't work. CD emulation not that good, the extra processors throw in more timing problems and 32X emulation has lots of timing issues. There are also suspected SH2 core bugs that come up more frequently on the 32X due to most games being programmed in assembly instead of C like most other SH2 platforms.

mednafen

Mednafen's Sega Genesis/Megadrive emulation is based off of Genesis Plus and information and code from Genesis Plus GX(old GPL-licensed version). The GPL-incompatible CPU and sound emulation cores in the aforementioned projects have been replaced with GPLed or GPL-compatible alternatives; heavily-modified and improved YM2612 emulation from Gens, and Z80 emulation core from FUSE.

Sega Genesis/Megadrive emulation should still be considered experimental; there are still likely timing bugs in the 68K emulation code, the YM2612 emulation code is not particularly accurate, and the VDP code has timing-related issues.

GENS

Close to Kega Fusion in features and compatibility, but has largely been surpassed by better emulators. There are many different forks and iterations of Gens, so your experience will differ quite a lot depending on which version you use.

Nuked-MD

Emulates the Mega Drive hardware at the gate-level and is thus extremely accurate, but this accuracy comes at the cost of very low performance. A more practical FPGA port is also available.

Nintendo Switch Online (m2engage)

• Genesis support was added to Nintendo Switch Online Expansion Pack in September 2021, alongside N64 games;
• Users are limited to the selection of games Nintendo chooses to make available on the service;
• Game lineup recycles pretty much everything from Sega Genesis Mini 1 and/or 2 minus the licensed IP (anime, manga, Disney, etc.) and Sega CD games;
• Supports online and Local Play (up to 2 players);
• Different games between regions (Japan and International)

Enhancements

Name		Genesis Plus GX	Kega Fusion	BlastEm	PicoDrive	ares	BizHawk	MAME	FinalBurn Neo
Netplay		✓	✓	✗	✓	✗	✗	✗	✗
Resizable Internal Resolution		?	?	?	?	?	?	?	?
Sprite Replacement		?	?	?	?	?	?	?	?
Built-in Graphics mod editor/manager		?	?	?	?	?	?	?	?
Internal Framerate Hack		?	?	?	?	?	?	?	?
Widescreen hack		✓	?	?	?	?	?	?	?
RetroAchievements Mega Drive, 32X, CD		~	?	~	~	?	✓	?	~
Overclock		?	?	✓	?	?	?	?	?
Built-in Cheat Manager		✓	?	?	?	?	?	?	?
Built-in Custom resolution/CRTSwitchRes For using this on Windows OS you need CRT Emudriver. Another option is using EDID editor tool such as "Custom Resolution Utility".		Exclusive to libretro cores and GroovyMAME at the moment.
Post-Processing	Filters	✓	?	?	?	?	?	✓	~
	Shader Chain	✓	?	?	?	?	?	✓	~
TAS features	Macros/Scripts/Lua	?	?	?	?	?	?	?	?
	Rewind	✓	?	?	?	?	?	?	?
	Fast-Forward/Turbo Speed	✓	?	?	?	?	?	?	?
	Savestates	✓	?	?	?	?	?	?	?
Input lag-mitigating technique		✓	?	?	?	?	?	?	?
Streamable compression format		✓	?	?	?	?	?	✓	?
Debug Features		?	?	?	?	?	?	?	?

Hardware features and accessories

Name	Genesis Plus GX	Kega Fusion	BlastEm	PicoDrive	ares	BizHawk	MAME	FinalBurn Neo
CD	✓	~	~	✓	✓	✓	✓	✗
32X	✗*	✓	✗*	✓	✓	✓	~	✗
Six Button Control Pad	✓	?	?	✓
Menacer	✓	?	WIP	?
The Justifier	✓	?	WIP	?
Sega Mouse	✓	?	?	?
Team Player	✓	?	WIP	?
4 Way Play	✓	?	WIP	?
J-Cart	?	?	?	?
Sega Virtua Processor	✓	✓	WIP	?
Sonic & Knuckles	✓	?	✓	?
XE-1 AP	✓	?	WIP	?
Activator	✓	?	?	?
Saturn Keyboard	✗	?	✓	?
XB∀ND Keyboard	✗	?	✓	?
Floppy Disk Drive	?	?	?	?
The Miracle Piano Teaching System	✗	?	WIP	?
System Converter	~	?	?	?
XBAND Modem	✗	✗	✗	✗
Mega Modem	✗	✗	✗	✗
Sega VR	Only possible with SegaVR-DGenSDL emulator.
TeeVGolf	?	?	?	?	?
Game Genie	✓	?	?	?	?
Action Replay	✓	?	?	?	?
MSU	?	?	?	?	?
SD Card Reader	✗	✗	✗	Beena	?

Lock-On Emulation

Lock-On Technology is a unique feature found on Sonic & Knuckles cartridges for the Sega Mega Drive/Genesis that allowed a player to connect an older game to the cartridge's pass-through port for extended or altered gameplay.

• With Sonic 3: Completes the game, adds the Sonic and Knuckles levels as intended. This was the original usage.
• With Sonic 2: Unlocks an alternate version of Sonic 2 with playable Knuckles.
• With Sonic 1: Unlocks the Blue Sphere minigame with a level select for all possible levels.

The Sonic & Knuckles cartridge can lock on to other cartridges:

• Smaller than 2MB: Will play a single random level from the Blue Sphere minigame generated from data in the header.
• Bigger than 2MB: Will boot to Sonic & Knuckles.
• Has Battery Pack: All saved data will be wiped out.

Most emulators don't support Lock-On save for Genesis Plus GX, but there are pre-combined ROMs for the Sonic trilogy available online that can be played as a regular Megadrive ROM on any emulator and still work. The Sonic 3 Complete romhack also achieves the same purpose.

Genesis Plus GX's RetroArch core includes true Lock-On emulation. From the Core Options menu, you can enable the Lock-On feature for either Sonic & Knuckles, Game Genie, or the Action Replay (Pro) -- the latter two using a different technology but with similar effects. Setting this option to anything other than "Off" will enable Lock-on to the cartridge you're currently playing as. After resetting, the game will boot in Lock-On mode.

The following files need to be under the directory for BIOS files (usually "system"):

• sk.bin (Sonic & Knuckles (2 MiB) ROM)
• sk2chip.bin (Sonic & Knuckles UPMEM (256 KiB) ROM): If you can't find it online, extract it with a hex editor from a pre-combined Sonic 2 & Knuckles ROM from offset 00300000 to the end of the ROM.

For GG/AR, the files needed are areplay.bin and ggenie.bin, but most emulators support cheat codes from these natively.

BlastEm also supports the Lock-On Technology

Modes

Mega Drive Plus / Genesis Plus / MSU-MD

The Mega Drive Plus / Genesis Plus (sometimes abbreviated as MD+) is a special mode for certain Genesis games that use enhanced CDDA tracks with a Sega CD. This was not used in any official games, however, the mode itself was first used in the first batch of Pier Solar releases. This feature was been documented to be used on Terraonion's Mega SD flash cartridge, to give similar effects for Genesis games in a way that MSU-1 does in patched SNES games. Another variant was been made for Mega Everdrive PRO, named MSU-MD.

Currently, only Genesis Plus GX supports both modes as mentioned here, while Kega Fusion supports games that can only run in MSU-MD mode.

A variant called 32x Plus (abbreviated as 32x+) made exclusively for Sega 32x games also exist, but again, it is only used by homebrew software, such as Doom 32x Resurrection.

Extended VRAM

A 128KB VDP mode from TeraDrive, an IBM PC/Mega Drive combo used on several Teradrive-only software.

On standard Genesis games, it is used in Space Harrier and Space Harrier II ports available on Genesis Mini 2 / Mega Drive Mini 2. BlastEm has partial support for this mode since version 0.5.0.

Hardware variations

Firecore

Firecore is a system-on-a-chip clone hardware based on the Sega Genesis/Mega Drive system, originating in the late 2000s. Most emulators have not been tested with Firecore-enhanced titles, however it is unlikely that they are supported.

Emulation of this clone only possible with Genesis-Plus-GX-Cyclone fork. There is a barely MAME support as well.

Pico

PicoDrive standalone version, KEGA Fusion and MAME supports this hardware. Keep in mind that PicoDrive libretro core or BizHawk core version doesn't have a stylus or turn page support, while the obsolete standalone version does. Also there is a feature request for ares emulator.

MAME 0.265 compatibility list

See dedicated page for more information.

Advanced Pico Beena

Latest MAME versions supports this hardware.

MAME 0.265 compatibility list

See dedicated page for more information.

Arcade

Sega released three arcade boards based on the Genesis / Mega Drive hardware:

• Mega Play
• Mega-Tech
• System C-2

In addition, several Genesis games were converted to stand-alone Arcade machines, either with or without a license from Sega.

MAME and FinalBurn Neo supports these arcade boards.

External links

• MegaDrive Development Wiki - A Wiki about every technical aspect of the SEGA MegaDrive hardware and software. It aims to provide the most detailed, accurate, and up-to-date information, to help homebrew development and repairs.
• Mega Drive emulators on Sega Retro
• ARCHIVE.ORG Console Library: Sega Genesis
• Genesis emulators on RomsPedia