Sega Genesis emulators
The Sega Genesis is a 16-bit, fourth-generation console released by Sega in 1988. 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).
Genesis emulation is very good, with high degree of game compatibility (many of them claiming 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. Genesis-based arcade boards and the Sega Pico are still sketchy, however.
|Name||Operating System(s)||Latest Version||SMS||GG||Mega Drive||Sega CD||32X||Recommended|
|Kega Fusion||Windows, Linux, OS X||3.64||✓||✓||✓||✓||✓||✓|
(Genesis Plus GX)
|Gens/GS||Multi-platform||r7/Gens/GS II Git Repository||✗||✗||✓||✓||✓||✓|
|Gens||Windows, Linux, BeOS||2.14||✗||✗||✓||✓||✓||✗|
|BlastEm||Windows, Linux, OS X||0.5.0||✓||✗||✓||✗||✗||✗|
(Genesis Plus GX)
|Genesis Plus GX||Wii, Gamecube||1.7.5 RC1||✓||✓||✓||✓||✗||✓|
(Genesis Plus GX)
* Only for the 32X as an open-source and cross-plaform alternative to Kega Fusion
- Genesis Plus GX is a solid emulator that claims 100% compatibility with Sega Genesis, Sega CD, Master System/GG and SG-1000 games. The only thing it lacks is 32X support. The RetroArch port adds shader support, dynamic sync and other enhancements, while the BizHawk port adds features useful for speedrunners.
- Kega Fusion is a very good emulator with high compatibility, coded by an ex-Sega staffer! It is easy to use and has plugin-based filter support. It has some issues on newer versions of Windows, though.
- Regen is accuracy-focused with high compatibility, but it lacks 32X and Mega CD support. It also supports overclocking.
- Exodus is cycle-accurate at the cost of very high system requirements. It is the newest Genesis emulator and is far from complete. It currently only supports the Sega Genesis.
- Gens is close to Kega Fusion in features and compatibility, but it has been largely surpassed by better emulators. There are many different forks and iterations of Gens, and your experience will differ quite a lot depending on which version you use.
- BlastEm aims for cycle accuracy but for lower system requirements than Exodus. It has substantially higher compatibility than Exodus but falls short of Genesis Plus GX.
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: Unlocks an alternate version of Sonic 3 with more levels.
- 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 to 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 save 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.