CD Injector 3DS

Turn PC Engine CD / TurboGrafx-CD and Sega CD / Mega CD games into installable 3DS CIAs. Each game gets its own Home Menu icon and banner, and everything it needs is packed inside the CIA.

Quick start

1. Download CD-Injector-3DS-vX.Y.Z-windows.zip from Releases, unzip it and run CD-Injector-3DS.exe.
2. Pick the console, then your game's .cue file and the BIOS.
3. Press Create CIA.
4. Copy the .cia to your SD card and install it with FBI.

Nothing gets installed on your PC. The app is for Windows; on Linux or macOS you can run the command line version from source (see Building from source). The rest of this page explains each step and every option.

Features

• Standalone emulators (TemperPCE and PicoDrive from emus3ds), so RetroArch isn't needed. The CIAs run on the original 3DS and 2DS as well as the New models.
• Self-contained. The whole CD image (every track, CD audio included) and the BIOS go inside the CIA.
• Boots straight into the game. Saves go to sdmc:/emus3ds/saves/<game>/, including when you close the game from HOME.
• Fills itself in. The game's title, publisher and year are filled in when the disc is recognised, and its picture too: from RetroArch's thumbnails on the PC, or downloaded with one click. See Filled in for you.
• Home Menu banners that stand out in 3D, with nothing else needed. Two designs of the app's own, in full color: your game's title screen set into a colored frame (laid out like NSUI's frame banners), or the game's cover in a CD case with the disc sliding out. Each has the Virtual Console title plate, written NSUI's way or Nintendo's, floating in front, so the banner stands out of the screen with the 3D slider up. The icon gets the silver border NSUI gives its icons.
• Or NSUI's own 3D banners: point the app at your copy of NSUI once and every game gets its picture and title on NSUI's Genesis, PC Engine, TurboGrafx-16 or frame banner. See Your options.

NSUI (New Super Ultimate Injector) makes CIAs for cartridge consoles but not for these two CD systems. This app covers that gap.

Status: stable. The emulators are tested on real hardware with Sonic CD (Sega CD) and Castlevania: Rondo of Blood (PC Engine CD). The 3D banners new in 1.2.0 (Frame and CD case in layers, and NSUI's banners made from NSUI) haven't been confirmed on a 3DS yet: if a banner doesn't show up right on the Home Menu, please open an issue with a screenshot. See Compatibility and the FAQ.

What you need

• The game as a .cue file with its .bin files in the same folder (a backup of a disc you own). For a .chd file, convert it first with MAME's chdman: chdman extractcd -i game.chd -o game.cue
• The console's BIOS file:
  • PC Engine CD: System Card 3.0, named syscard3.pce
  • Sega CD: bios_CD_U.bin (USA), bios_CD_E.bin (Europe) or bios_CD_J.bin (Japan), matching the game's region
• A 3DS with custom firmware and FBI (or a similar tool) to install the CIA.

This app includes no games and no BIOS files.

Step by step

The window has five numbered steps. Each shows a green check when it's done, and the line at the bottom always says what to do next. The How to use button repeats all of this inside the app.

1. Console. Choose PC Engine CD or Sega CD. The rest of the window unlocks.
2. Game. Choose the .cue file, or the folder that holds it. The app checks the disc and warns you if it looks like a different console.
3. BIOS. Choose the BIOS file, or the folder it's in. If you leave this empty, the app searches next to the game.
4. Banner and icon (optional). Everything has a default, so you can skip it. See Your options.
5. Create the CIA. Choose the folder to save it in (empty means next to the game's folder) and press Create CIA. It takes about a minute.

Then copy the .cia to your 3DS's SD card. On the 3DS, open FBI, choose SD, find the file and choose Install CIA.

Your options

All of these are in step 4. None of them are required.

Option	What it does
Game title, Publisher, Year	Shown on the banner's plate and under the icon on the Home Menu. Filled in for you when the game is recognised (see below), else the title comes from the file name; change any of them if you like. Titles in any language work, Japanese included.
Picture	A title screen or box art. It becomes the picture on the banner and the icon. Found for you in RetroArch's thumbnails when they're on the PC, or press Download to fetch it from libretro's thumbnails.
Banner: Frame	Your picture set into a colored frame. Pick the frame color from the swatches, choose Custom... for any color, or Reset for the console's own (orange for PC Engine CD, blue for Sega CD).
Banner: CD case	The game's cover in a CD case, with the disc sliding out and the title screen printed on the disc.
Cover (CD case only)	The game's box art for the case. Found for you like the picture, fetched with Download, or chosen with Choose a picture...; without one, the picture is used.
Banner: 3D banner from NSUI	Uses NSUI's 3D banners, made from your copy of NSUI or exported from it. See below.
More options...	How the picture fits the icon, how the plate's text is written (NSUI's way or Nintendo's), your own banner sound, the font used on the title plate, and how the title, year and pictures are filled in.

The preview in the window shows the banner and icon as they'll look on the top screen. Both of the app's own banners are stored in full color (8 bits per channel; bannertool's own banners have 4) and are made of layers at different depths, like NSUI's 3D banners: with the 3D slider up, the plate floats in front and the rest sits behind it.

• Frame. The frame, the picture and the title plate have the same size and place as in NSUI's frame banners, so a CD game sits well next to your GBA, NES or Genesis ones. The picture is set a little behind the frame. A title screen at a console's own resolution (256 x 224, 320 x 224 and so on) is first stretched to the 4:3 shape a TV gave it, and a 4:3 picture loses a little at the top and bottom (about 7% each) to fill the window, which is as wide as a GBA screen.
• CD case. The case takes the cover's shape: square for a jewel case (PC Engine CD and Japanese Mega-CD covers), taller for the long cases of American Sega CD games. The disc sits behind the case.
• The title plate matches NSUI's: its badge, rim and face, the title in Arial Bold at 11 pt on one or two lines (8.5 pt when it needs three), and "Released: year" below. Or, with Plate text > Official style, the text is laid out like Nintendo's own Virtual Console banners (see More options).
• The icon is your picture inside the silver Virtual Console border NSUI gives its icons.

Filled in for you

When you choose a game, the app works out which disc it is and fills in the title, publisher and year. It never replaces anything you typed or chose, and recognising the disc never goes online.

• Sega CD discs carry their own serial number and year, so they're recognised whatever the files are called.
• PC Engine CD discs carry no such details. They're recognised by their data track (its size and checksum, as listed by Redump) or by their .cue name when it's the disc's Redump name. A patched or fan-translated disc isn't in the lists, so its title comes from the file name.
• The picture comes from RetroArch's thumbnails when RetroArch is on the PC (a title screen if there is one, else a screenshot, else box art), or from a folder of your own pictures named after the games (More options > Pictures folder).
• The cover for the CD case banner is the game's box art, found the same way.
• Or download it: press Download next to the picture (or next to the cover), and the app fetches the game's title screen (or box art) from libretro's thumbnails, the collection RetroArch and NSUI use. A game whose picture libretro keeps under a slightly different name is found too. To do that for every game that has no picture on the PC, turn it on in More options. Each picture is downloaded once and kept with the app's settings (%APPDATA%\CD Injector 3DS\pictures).

The details come from the lists of Redump (via libretro's database) and MAME, which come with the app. They cover about 560 PC Engine CD and 580 Sega CD discs. You can turn filling in off in More options.

Making a game you made before? The CIA's title ID and its save folder come from the title. If the title filled in now differs from the one you used then, type the old one to update that copy and keep its saves.

A banner and icon from NSUI

NSUI can't make CIAs from Sega CD or PC Engine CD games, but it can for cartridge games, and its banners are 3D. The app can use NSUI's banners for your CD games, with each game's own picture and title on them:

• Genesis / Mega Drive with a TV, for Sega CD games.
• PC Engine with a TV or TurboGrafx-16 with a TV, for PC Engine CD games, or both: the PC Engine on Japanese 3DS systems and the TurboGrafx-16 on the others, the way NSUI's own PC Engine banner does it.
• 3D frame (NSUI's GBA-style frame), for either: your picture goes in the frame.

Your picture goes on the TV's screen (stretched over it, as NSUI does) or in the frame, and your title and year on the plate. Each console's own banner tune plays, as with NSUI.

Made from your NSUI (the easy way). NSUI keeps the parts of its banners (the 3D models and the tunes) inside its program file, and the app puts the banner together from them the same way NSUI does:

1. Set Banner to 3D banner from NSUI.
2. Next to From NSUI, pick the banner and click Make. The first time, choose NSUI's program, New Super Ultimate Injector for 3DS.exe, in your NSUI folder. The app remembers where it is (NSUI… chooses another), and it remembers the banner for the console selected in step 1: make the Genesis one with Sega CD selected and the PC Engine one with PC Engine CD selected.
3. Choose the game's Picture as usual. Leave Icon file empty and the icon is made from your picture, with the same silver border NSUI gives its icons.

The banners made are kept with the app's settings (%APPDATA%\CD Injector 3DS\nsui banners). The app only reads NSUI's program file: nothing of NSUI's comes with this app, and nothing is changed in your NSUI folder. On the command line, --nsui "<NSUI folder>\New Super Ultimate Injector for 3DS.exe" does the same, with --console to pick the banner (genesis, pc_engine, turbografx_16, by_region or frame).

Exported from NSUI. A banner you export from NSUI works too: in NSUI, set up any game of that console (the title screen and title don't matter), export its banner (<game>_banner.bin) and choose it as Banner file. A "3D frame with color" banner keeps the frame color you picked in NSUI.

The 3D models, their colors and movement, the plate's badge and the tune stay NSUI's: only the textures for the picture and the plate are rewritten. NSUI's PC Engine banner keeps a copy of the plate and the TV's picture in each of its 13 language sections, and those copies are what the 3DS shows, so they all get the game's title and picture. The preview shows the banner's 3D model and plate as a still picture.

More options

• Icon picture: how your picture fits the square icon (fill top to bottom, or side to side). The other direction gets black bars.

• Banner sound: a .wav (8- or 16-bit PCM, at most 3 seconds) or a .bcwav that plays on the Home Menu. Empty means a short chime made by this program. An NSUI banner keeps its own sound.

• Plate text: how the title and year are written on the Virtual Console plate.

  • NSUI style (the default): as NSUI writes them, in Arial Bold, so the plate matches your NSUI-made games.
  • Official style: laid out like Nintendo's own Virtual Console banners, measured from them. A title that fits takes one line of 12-pixel capitals, and a long one is squeezed a little rather than shrunk. A longer title takes two lines of 10-pixel capitals, split after a colon if it has one. "Released: year" is spaced out the way Nintendo does it, and the ink is Nintendo's softer gray. The font is M PLUS 1p Bold, a free look-alike of Nintendo's Rodin that comes with the app, unless you choose a font below.

• Title plate font: any .ttf or .otf file, used for the title and "Released" text on the plate. Empty means Arial Bold in NSUI style and M PLUS 1p Bold in official style. Nintendo's own Virtual Console banners use Rodin; Sony's "SCE-PS3 Rodin Latin Bold" looks closest to it. It can't be included here, but it works if you point the app at your own copy (an RPCS3 install has it at dev_flash\data\font\SCE-PS3-RD-B-LATIN.TTF). With official style it gives the closest match to Nintendo's banners.

• Fill in: turn off filling in the title, publisher, year and pictures when the game is recognised.

• Pictures folder: where to look for each game's picture: RetroArch's thumbnails folder, or your own folder of pictures named after the games. Empty means RetroArch's thumbnails, if RetroArch is on the PC.

• Download the picture when there's none on this PC: off by default. When it's on, the app downloads the picture (and, for the CD case, the cover) of every recognised game that has none on the PC.

The NSUI banner and icon fields also accept an ordinary picture (PNG, JPG and so on) to use as the banner or icon as it is.

Good to know

• The CIA is about the size of the disc. FBI needs that much free space again while installing; you can delete the .cia afterwards. On the PC, the build needs about twice the disc's size free in your TEMP folder.
• Making the same game again with the same title keeps its title ID, so installing it again updates the earlier copy and keeps its saves. The app shows the title ID when it finishes.
• A game freezes or glitches: touch the bottom screen for the emulator menu and try the other CPU Core setting (PC Engine CD). The setting is remembered per game.
• Never share a CIA you made. It contains the game and the BIOS.

Command line

python cd_injector.py build "Game folder" --system pce --bios Bios --title "Game Title" --year 1993 --image title.png --frame-color "#d63030"
python cd_injector.py build "Game folder" --banner-style cdcase --cover box.png --plate-style official
python cd_injector.py build "Game folder" --download-picture --nsui "C:\NSUI\New Super Ultimate Injector for 3DS.exe" --console turbografx_16
python cd_injector.py build "Game folder" --system segacd --banner-file game_banner.bin --icon-file game_icon.bin
python cd_injector.py build --help

What you don't give is filled in as in the app: the title, publisher, year and picture of a recognised disc (turn it off with --no-lookup), with --pictures <folder> to look somewhere else and --download-picture to fetch a missing picture. The banner is chosen with --banner-style frame|cdcase, --nsui/--console (NSUI's banners) or --banner-file, and the plate's text with --plate-style nsui|official and --plate-font. --help lists them all.

Compatibility

The app packs any valid disc image; whether a game runs well is up to the emulator. These results were checked on real hardware:

Game	System	Result	Notes
Sonic CD (USA)	Sega CD	Runs
Castlevania: Rondo of Blood (English patch v1.03)	PC Engine CD	Runs	Froze after the opening cutscene with TemperPCE's fast CPU core; runs with the compatible core, which is the default for CIAs from this app.

Tried another game? Please open a compatibility report with the result, even if it didn't work.

FAQ

Does it work on an original 3DS or 2DS? The emulators (from emus3ds) run on every 3DS and 2DS model. How smoothly a game runs depends on the game, and the New models have more headroom. Please say which model you used in a compatibility report.

How is this different from a RetroArch forwarder? There's nothing to set up on the SD card. The emulator, the game and the BIOS are all inside the one CIA, and it boots straight into the game.

Can I use a .chd, .iso or MP3/OGG version of the game? Convert a .chd to .cue + .bin first (see What you need). A .cue with .bin tracks is the format that has been tested.

Where do my saves go? To sdmc:/emus3ds/saves/<game>/ on the SD card, so they survive reinstalling the CIA or making it again.

A game freezes or glitches. What can I try? Touch the bottom screen to open the emulator menu. For PC Engine CD games, switch the CPU Core setting; it's remembered per game. If that doesn't help, please file a compatibility report.

Windows or my antivirus warns about the app. Is it safe? The app isn't code-signed, so SmartScreen warns the first time (choose More info, then Run anyway). Some antivirus programs also flag apps packaged with PyInstaller by mistake. Compare the download with SHA256SUMS.txt from the release, and the full source is in this repository if you'd rather build it yourself.

How do I remove a game I installed? In FBI, open Titles, pick the game and choose Delete Title. You can also use System Settings > Data Management on the 3DS. Its saves stay on the SD card in the folder above.

Can I share the CIAs I make? No. They contain the game and the BIOS.

Privacy and security

• No tracking, and online only when you ask. The app collects nothing. It goes online only to download a game's picture or box art: when you press Download, or for every game if you turn that on in More options. It then fetches that one picture from libretro's thumbnails on GitHub and sends nothing about you or your PC.
• It reads only the files you choose (NSUI's program included, which it only reads: it never runs or changes it), and writes only the CIA, temporary files (removed when it finishes), the pictures it downloads, the NSUI banners you make and a small settings file (%APPDATA%\CD Injector 3DS\settings.json) with the paths and colors you picked.
• Files are checked before use. A damaged, oversized or booby-trapped .cue, banner, icon, picture or sound gives an error message instead of being used. Only files inside the game's own folder are packed into a CIA.
• Checking a download. Each release has a SHA256SUMS.txt; compare it with Get-FileHash <the zip> -Algorithm SHA256. The program isn't code-signed, so Windows SmartScreen may warn the first time you run it.
• Reporting a problem. See SECURITY.md.

How it works

Each CIA holds the patched emulator plus a RomFS containing:

• game/<title>.cue and its tracks
• the BIOS
• boot.txt, which points at the game

The patch (patches/autoboot-forwarder.patch, against R-YaTian's emus3ds) makes the emulator:

• boot that game directly
• load the BIOS from RomFS
• redirect saves, save states and settings to the SD card
• save on exit
• default to TemperPCE's compatible CPU core
• disable PicoDrive's blank RAM cartridge
• fall back to English when the Chinese font isn't installed
• avoid a crash on exit caused by unmounting RomFS while tracks are open

Names inside the CIA are kept to plain ASCII (the tested case on the 3DS): accents are dropped, and a title with no Latin letters is stored as Game <id>. The name you typed still shows on the Home Menu.

Building from source

1. Emulators and tools (Linux or WSL with devkitPro 3ds-dev + 3ds-zlib, gettext, curl, unzip, g++-mingw-w64-x86-64): scripts/build_emulators.sh. It builds the patched emulators from a pinned emus3ds commit, builds bannertool from a pinned commit, and downloads the official makerom release (checked against its SHA-256).
2. Windows app (Python 3.10+ in a virtual environment; pip install -r requirements-build.txt pins Pillow and PyInstaller): powershell -File scripts\build_windows.ps1 -Python .venv\Scripts\python.exe. It runs the checks and tests first, then writes the app folder, the zip, the emulator source archive and SHA256SUMS.txt.

Releases are built by the release workflow (Actions > release > Run workflow, on main). It packages the version in cdinjector/__init__.py with the notes from its section of CHANGELOG.md. While the emulators and tools are unchanged, it takes them from the last release built with them, checked against their SHA-256 (see the workflow).

Run the tests on their own with python -m unittest discover -s tests -t .. See CONTRIBUTING.md before sending changes.

Credits and licenses

CD Injector 3DS's own code is MIT-licensed (see LICENSE): use it, change it and share it freely, with credit. The download also bundles other people's work, which keeps its own terms:

• emus3ds by bubble2k16, continued by R-YaTian
• Temper by Exophase
• PicoDrive by notaz, irixxxx and contributors
• bannertool by Steveice10 (MIT)
• makerom by 3DSGuy, applestash and Jakcron (MIT)
• M PLUS 1p Bold by the M+ Project Authors (SIL Open Font License 1.1), the official-style plate font

The list of games the app recognises (cdinjector/gamelist.py) comes from libretro's database (CC BY-SA 4.0) and MAME's software lists (CC0), and is shared under CC BY-SA 4.0.

PicoDrive's license means the download as a whole is free and non-commercial, and every release includes the complete emulator source. The MIT license covers this project's own code only and doesn't change those terms. See THIRD-PARTY-NOTICES.md for the details.

Not affiliated with or endorsed by Nintendo, Sega, NEC or the NSUI authors.