YoshiNESRecomp

YoshiNESRecomp

This recompilation is a byproduct of developing nesrecomp — the games are the proving ground, the framework is the goal. These are in-development previews, not finished ports — expect rough edges, and depth will keep landing over months, not days. My time for any one title is limited, so I ask for your patience. Contributions are welcome — testing, issues, and PRs to the game or framework all help and will accelerate this game's polish. More on the why at: Recomp + AI: 5 Months Later »

Static recompilation of Yoshi (NES) for native PC. Built with the NESRecomp framework.

Status: Believed fully playable. Title screen, single-player puzzle mode, two-player versus, and the demo all run end-to-end. If you find a bug, please open an issue.

Cycle backend migration branch

Default cycle controls: arrows move, Z is A, X is B, Enter is Start and Backslash is Select. Escape opens the menu, Tab fast-forwards, and F8/F9 save/load the cycle state. Use Controls to remap inputs in config.ini. Older keybinds.ini and F5/F6/F7 instructions below apply to the legacy host.

The normal build now uses the cycle CPU backend. Code is generated from the original ROM during configure and stays in the build directory. Run setup.bat or setup.sh to initialize the pinned engine/UI submodules, then configure:

cmake -S . -B build-cycle -DNESRECOMP_ROM="/path/to/Game.nes"
cmake --build build-cycle --config Release --parallel 4

Version 1.2.1 uses the verified USA retail payload E7EAD93B (128 KiB PRG, 32 KiB CHR), replacing the previous larger input. Both the catalog header and the old header that incorrectly declares 64 KiB CHR are supported for this complete payload. See ROM header details. Saves/states from the previous different image are not qualified for this release.

Run the executable with that same ROM path. The launcher verifies the image; the runtime also verifies cartridge metadata and PRG identity. NESRECOMP_ROOT and NESRECOMP_RECOMP_UI can name other checkouts, and cross builds accept NESRECOMP_HOST_COMPILER pointing to a runnable host compiler.

Keep the old generated sources and select them explicitly with -DNESRECOMP_BACKEND=legacy in a separate build directory. Legacy save states cannot be loaded by the cycle backend; its cartridge shortcut slot uses saves/<ROM stem>.cycstate. Preserve existing saves and settings during rollout. Cycle-native comparisons use nesrecomp/tools/cyc/cyc_verify.py; --interp-only runs the cycle interpreter for diagnosis. Earlier --verify / --emulated Nestopia entry points remain in the legacy build.

The owner accepted the original short Windows migration playtest on 2026-10-04. Version 1.2.1 additionally checks header acceptance, launcher Play and 900-frame native/interpreter startup parity with the verified USA image. These checks do not establish full-game completion or qualification on other platforms.

What Works

• Title screen
• Single-player puzzle mode (Type-A and Type-B)
• Two-player versus mode
• Score, level, and speed display
• The attract-mode demo
• Both controllers

Quick Start

1. Download YoshiNESRecomp-windows-x64.zip from Releases
2. Extract and run YoshiRecomp.exe
3. Select your Yoshi (USA) ROM when prompted — the path is saved for future launches

Controls

NES Button	Keyboard
D-Pad	Arrow keys
A	Z
B	X
Start	Enter
Select	Tab

Hotkey	Action
F5	Toggle turbo (fast-forward)
F6	Save state
F7	Load state

Yoshi is a puzzle game with no battery save, so save states are the way to bookmark a session.

Building from Source

Requires Visual Studio 2022 and CMake 3.20+.

git clone https://github.com/mstan/YoshiNESRecomp
cd YoshiNESRecomp

# Windows
setup.bat

# Linux / macOS
chmod +x setup.sh && ./setup.sh

This initializes the pinned nesrecomp submodule and links the Nestopia oracle core.

Then build:

cmake -S . -B build -G "Visual Studio 17 2022" -A x64
cmake --build build --config Release

Place your Yoshi (USA) ROM in the build directory or select it at runtime.

Architecture

This is a static recompiler, not an emulator. The original 6502 machine code is translated to C at build time, then compiled to native x64. The NES PPU, APU, and MMC1 mapper are simulated by the runner library.

• game.toml — recompiler configuration (data regions, dispatch extras)
• extras.c — game-specific hooks (TCP debug server, verify-mode integration)
• verify_mode.c — optional dual-execution verification against a Nestopia oracle
• generated/ — auto-generated C code (do not edit manually)
• nesrecomp/ — framework, consumed via directory junction + pin file

Known Limitations

• Audio is basic (APU register writes are captured but full audio mixing is work-in-progress)

License

PolyForm Noncommercial 1.0.0 — see LICENSE. Third-party components retain their own licenses.

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_{R.A.I.D. — Retro AI Development · a Discord for AI-assisted retro reverse-engineering, decomp & recomp}

Cycle Windows builds use tools/build.ps1 -Rom <original-ROM>. Create a ROM-free ZIP with tools/make_release.ps1 -Rom <original-ROM>; -SkipBuild -BuildDir build-cycle packages an existing production cycle build. Legacy C remains available through explicit CMake selection.