EstebanPdN/zelda-alttp-3ds

Nintendo 3DS dual-screen port of Zelda3, built with help from Codex.

This project is based on open-source work from:

• Original reverse-engineered Zelda3 engine: https://github.com/snesrev/zelda3
• Android port base: https://github.com/Waterdish/zelda3-android
• Dual-screen Android branch used as the 3DS source base: https://github.com/samyost1/zelda3-android

No ROM or extracted game asset package is distributed in this repository. Each user must provide their own legally obtained USA, unheadered ROM on their own 3DS SD card.

https://discord.gg/zy8BqH5ss

• Top screen: 400x240 gameplay.
• Bottom screen: 320x240 live map, dungeon map, gear view, item selection and touch settings.
• First launch extracts zelda3_assets.dat locally from the user's ROM.
• Display modes: wide mod, stretched original and original aspect.
• Turbo speed: off, x2, x3, x4 or x5.
• New 3DS: ZL or C-stick can hold turbo when turbo is enabled.
• Quick diagnostics: press L + R + A to create a dump with memory files, physical 400x240/320x240 screen captures, raw display framebuffers and a validated load-state.bin checkpoint. Audio pauses during capture and a DUMP SAVED notice confirms complete success on the top screen.
• Developer settings can load the newest dump checkpoint for the active ROM profile and optionally show the current FPS on the top screen.
• PICA200/Citro2D presentation for both screens with nearest-neighbor sampling and RGB565 display output.
• PICA200 GPU rendering on Old 3DS, with automatic software fallback for unsupported effects. New 3DS uses its existing CPU renderer.
• Native 400x240 WIDE mode, fixed-camera edge corrections and persistent per-ROM display, zoom, turbo and control settings.
• Responsive map controls and independent heart updates on Old 3DS.
• Fixed-step 60 Hz gameplay timing with bounded catch-up instead of making game speed depend on when a VBlank wait returns.
• Parallel PPU scanline rendering on Core 0 and Core 1, plus Core 2 on New 3DS, with persistent tile-row caches and frame-time diagnostics in quick dumps.
• HOME Menu banner uses a lightweight custom CGFX 3D logo model with the supplied hover sound converted to a short PCM WAV.

Install the CIA, then create this directory on the SD card:

sdmc:/3ds/Zelda 3DS/

Place a legally obtained USA, unheadered ROM there. The preferred filename is zelda3.sfc, but the setup also accepts other .sfc or .smc filenames.

On first launch, press A to validate the ROM and extract the assets. The ROM is read locally and is never copied into the CIA.

If you’re using a translated/patched ROM, put both the clean USA ROM and the patched ROM in sdmc:/3ds/Zelda 3DS/.

The port should use the clean ROM for the original assets and the patched ROM for the translated text. Translation patches may work this way, but gameplay hacks are not guaranteed to be compatible.

Audio requires:

sdmc:/3ds/dspfirm.cdc

Luma3DS can create this file from the console's own firmware through Rosalina's Dump DSP firmware command.

Every GitHub release includes:

• installable CIA
• Homebrew Launcher 3DSX
• QR code for scanning the CIA URL from FBI on a 3DS

GitHub supplies automatic source-code archives for each tag. The release page shows the QR code, a short changelog and bug-report instructions. Detailed development notes are preserved inside the source snapshot.

Latest release: v3.0

See CHANGELOG.md for the changes since v2.8.

Press L + R + A while the issue is visible and attach the resulting dump from:

sdmc:/3ds/Zelda 3DS/dumps/

Requirements:

• devkitARM, libctru and 3ds-cmake under DEVKITPRO
• makerom and bannertool for CIA packaging
• the vendored SDL2 source in app/jni/SDL2
• banner.cgfx is prebuilt in platform/3ds/assets; it was generated from the supplied 2.0 Blender logo model.

Build:

chmod +x platform/3ds/build.sh
platform/3ds/build.sh

The script builds the 3DSX and CIA under build-3ds/game/.

The Zelda3 engine retains the MIT license and copyright notices in app/jni/src/LICENSE.txt, which also contains the Opus notice. SDL2, SDL2_mixer and other dependencies retain their own licenses. These component licenses do not grant rights to Nintendo game content.

This repository contains only source code, build scripts, redistributable port assets and patch/extraction logic. It does not include a ROM, extracted game assets, or zelda3_assets.dat.

Users are responsible for providing their own legally obtained compatible ROM.

Thanks to @999sian for her Old 3DS optimization work, arth78 for the WIDE display contribution, and Archaistic for the WIDE height and Triforce improvements.

Logo work by Phibonacci, based on the original 3D model by TiraArt.

See 3DS controls and diagnostics.

In Settings > Update, choose Stable or Pre-release. Tap the release name to read its changelog on the top screen, with Prev/Next below for more pages. Choose Download Update and confirm installation, then reopen the game. Save in-game before installing. Startup checks also indicate newer releases.

Version v3.2 is the latest stable release. Select the Stable channel to install it. It fixes Restart retaining stale game RAM after ROM reselection, which could leave gameplay black and silent. It also batches updater SD transfers and prevents downloads from being starved by rendering.

Settings is Screen, Turbo Speed, Developer, Update, Restart. Restart opens the ROM selector and starts the selected ROM fresh; existing saves remain.

Version 3.1 uses the native HID contact flag for touch press and release detection, including startup and releases with residual coordinates. Physical coordinates remain protected from SDL viewport transforms. The last 32 touch selections are included in diagnostic dumps. Use the FBI QR if touch controls prevent opening Update.