Sega CD and 32X Emulation Setup Guide for Handhelds

The Sega CD and 32X were Sega's add-ons for the Genesis, and both have small but interesting libraries. The Sega CD brought disc-based games with full-motion video and CD-quality music. The 32X added more processing power for a handful of beefier titles. Emulating them is straightforward once you know about the BIOS files each one needs. That BIOS step trips up a lot of people, so this guide focuses on getting it right.

We cover the cores to use, the BIOS files you need, how to get CD audio playing, and how to load games. We frame all of this around playing games you already own.

Affiliate disclosure: This page contains affiliate links. As an Amazon Associate and Anbernic affiliate, we earn from qualifying purchases at no extra cost to you.

A Quick Primer on the Add-ons

The Genesis had two major add-ons. The Sega CD, known as the Mega CD outside North America, added a disc drive for bigger games with video and CD music. The 32X plugged into the cartridge slot and added processing power for more demanding games. Both are light to emulate on a modern handheld. The catch is that each needs the correct BIOS to run.

Which Cores to Use

On most handhelds you run these through RetroArch cores.

• Sega CD: the Genesis Plus GX core handles Sega CD games well and is the common choice. The PicoDrive core also supports Sega CD.
• 32X: the PicoDrive core is the standard for 32X games. Genesis Plus GX does not handle 32X.

A simple approach is to keep both cores installed. Use Genesis Plus GX for Genesis and Sega CD, and PicoDrive for 32X. Our RetroArch setup guide covers installing cores.

What You Need

• Any retro handheld, since these are light to emulate
• The Genesis Plus GX and PicoDrive cores
• The correct BIOS files
• Your own Sega CD and 32X games

Step 1: Add the BIOS Files

This is the most important step. Sega CD needs region BIOS files, usually one each for the US, Japanese, and European versions. The 32X also needs a small set of BIOS files. Without them, games will not boot.

You must supply these from hardware you own. We do not link to BIOS downloads. Place the BIOS files in your RetroArch system folder. RetroArch and the cores look for specific filenames, so do not rename them. If a game fails to boot, a missing or misnamed BIOS is almost always the reason.

Step 2: Add Your Games

Sega CD games are disc images. Use .cue with .bin, or the compressed .chd format. The .chd format is strongly recommended, since Sega CD discs are large and .chd saves a lot of space while keeping the CD audio intact.

32X games are cartridge files, often with a .32x extension. They need no special handling beyond the BIOS.

Place each in the matching system folder for your firmware, then scan the folder in your frontend.

Step 3: Get CD Audio Working

Many Sega CD games are famous for their soundtracks, so you want the music playing. The key is using a disc image format that preserves the CD audio tracks. A proper .chd made from a complete disc keeps the audio. If a game runs but the music is missing, your disc image is probably missing its audio tracks. Re-create the .chd from a complete source you own.

Step 4: Display and Settings

These games run at Genesis-era resolutions, so they look great on any handheld. A CRT shader suits the era well, and integer scaling keeps the image clean. Our RetroArch shaders guide covers presets. For full-motion video games, expect the grainy look of the era, which is part of the charm.

Games Worth Trying

A few highlights from both add-ons, all worth owning:

• Sonic CD (Sega CD). One of the best Sonic games, with time travel and a fantastic soundtrack.
• Lunar: Eternal Blue (Sega CD). A beloved RPG with voice acting and animated cutscenes.
• Snatcher (Sega CD). Hideo Kojima's cult cyberpunk adventure, highly sought after.
• Knuckles' Chaotix (32X). A unique Sonic spin-off built around a tethered two-character mechanic.
• Virtua Fighter (32X). An early 3D fighter port that pushed the add-on hardware.

Troubleshooting

Game will not boot. Almost always a missing or misnamed BIOS. Confirm the right region BIOS is in your system folder with the exact filename.

No music on a Sega CD game. Your disc image is missing audio tracks. Re-make the .chd from a complete disc.

32X game does not run. Make sure you are using the PicoDrive core and that the 32X BIOS files are in place. Genesis Plus GX will not run 32X games.

Recommended Handhelds

Sega CD and 32X run on nearly anything, so any budget device works. The

For more Sega gaming, see our best Genesis games and best Sega Master System and Game Gear games lists.