breyncast

Dreamcast → PC / Mobile

Independent technology for bringing Dreamcast software to modern platforms.

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breyncast — local buildHow it will work
# User supplies their own legally obtained software
breyncast build \
  --source "/my-dreamcast-game" \
  --target windows-x64 \
  --mode native

# Analysis and transformation happen locally
breyncast run ./build/game
◈ Goal: local build. Your game never leaves your PC.
Development journal

Devlog

Real progress, tests, compatibility work and technical decisions. Published in Spanish, English and Japanese.

View full devlog →
The devlog is ready. The first entry will appear here.
Current status · revision r246

Real games, running today

Screenshots from our lab: each one is the original game's SH-4 code, recompiled and running as a native program.

Tokyo Bus Guide

Tokyo Bus Guide

Playable
JP

Start to finish: 3D driving with the HUD, passenger window, cutscenes, VMU saves, music and sound effects. Windows EXE tested with an Xbox controller.

ChuChu Rocket!

ChuChu Rocket!

Playable
JP · PAL

Four-player battle and CD-Audio music. The PAL version runs in English or Spanish depending on the console language.

Puyo Puyo DA!

Puyo Puyo DA!

Playable
JP

Menus, character select and full matches, with sound.

Sega GTSega GTSega GT

Sega GT

Playable
PAL

Sofdec intro video, garage, license tests and races with a live speedometer, map and lap times.

Shenmue IIShenmue IIShenmue II

Shenmue II

In progress
PAL · disc 1

Intro, title screen and the 3D opening scene with textures for more than 2,000 frames. Right now: the skin and hat in the close-up.

Screenshots from our test lab, for technical documentation purposes. Games and trademarks belong to their owners; Breyncast does not distribute them and is not affiliated with them.

How it works

Static recompilation, not emulation

The game's code is translated once into C and compiled as a native program. There is no SH-4 interpreter or JIT at runtime; the hardware the game talks to (graphics, sound, controllers, GD-ROM) is reimplemented.

Your discThe game's executable, 1ST_READ.BIN, is extracted from your copy's GDI.
TranslationThe translator (C++) discovers the game's functions and emits equivalent C, instruction by instruction.
CompilationGCC or MinGW compile that C and link it with the runtime: PowerVR2, AICA, Maple, VMU, GD-ROM and flash.
Native executableOne program per game with its own front end: window, gamepad, audio and GPU rasterization (OpenGL).
5commercial games running
19,673functions translated in Shenmue II
246documented revisions
0SH-4 interpreters at runtime

Our working rule: The internet and source code as the map; the binary as the judge. Every step is verified with deterministic runs, checks against an independent decompilation project and a reference SH-4 interpreter.

Your games. Your computer.

Breyncast provides the technology. You provide your copy.

Breyncast does not distribute Dreamcast games, BIOS, firmware or proprietary content. Processing is performed locally using software supplied by the user.

1 · Your copySoftware legally obtained by the user.
→
2 · BreyncastAnalysis, translation and compatibility through independently developed technology.
→
3 · Modern executionA result prepared locally for the target platform.

Privacy by design: game content does not need to be uploaded to our servers.

One source

Multiple platforms

One compatibility technology, with native targets for PC and, progressively, mobile devices.

Native approach

Real performance

Native code optimized for each platform. No traditional emulation. No unnecessary compromises.

native runtime
while (running) {
    update();
    render();
}
breyncastFPS
Modern C++

Built by developers

Built with C++ and a lot of love for the Dreamcast legacy. In continuous development, with a growing library of playable titles. Developed with the help of Anthropic's Claude AI (Fable 5.1 model).

Clear direction

One project,
one path

From Dreamcast to modern platforms.
Step by step, with quality and no shortcuts.

Support the project
Dreamcast
FoundationDoneAnalysis, testing and documentation
Core CompilerWorkingCompilation engine and optimizations
Native PCIn progressWindows and Linux; Mac later
Native MobilePlannedAndroid and iOS
BeyondFutureNew platforms and possibilities

Support Breyncast

Your support funds development of the technology, not distribution of games.

Patrons will get access to Breyncast to compile supported games on their own PC. For that they will need a backup of an original disc they own and its 1ST_READ.BIN. The translation happens on the user's computer: Breyncast does not provide any proprietary files from Sega or third parties.

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