Virtua NBA Recompilation

VIRTUA NBA - RECOMP

A static recompilation of Virtua NBA (Sega NAOMI, 2000) for Windows and Linux. Made by Pocket_lucho with Claude. Leer en español

The game's SH-4 machine code is translated ahead of time into C++ (one function per basic block) and compiled to native code. The rest of the NAOMI hardware (PowerVR2 graphics, AICA sound, Maple/JVS input, cartridge) is provided by a fork of Flycast.

If you want to support me: https://buymeacoffee.com/pocket_lucho

What you need

• Your own Virtua NBA romset (virnba.zip, MAME naming).
• The NAOMI BIOS (naomi.zip) — only for the first start, to create a boot snapshot. After that, the game boots straight to the SEGA logo without it.
• Windows 10/11 x64, or Linux x86_64 (glibc 2.35+, e.g. Ubuntu 22.04 or newer).

No game code, graphics, sound or BIOS is included in this repository or in the releases. The recompiled code is generated on your PC from your own ROM (see below).

Getting started (Windows)

1. Download the release zip and extract it.
2. Copy virnba.zip to roms\ and naomi.zip to data\.
3. Run BUILD_GAME.bat (once). It
   • downloads the free llvm-mingw compiler (180 MB, first time only, checked by SHA-256),
   • runs the game up to its entry point and decodes its whole program into C++ (~76,000 blocks, a few seconds),
   • compiles it into vnba_game.dll (3–15 minutes depending on the CPU),
   • deletes the generated sources.
4. Run VirtuaNBA-Recompiled.exe. Tab / the Settings menu opens the options.

Features

• Native performance (recompiled code, no JIT), cycle-exact fallback for anything not precompiled.
• BIOS-free boot from a snapshot, one per BIOS region (Japan, USA, Export, Korea), region selector.
• Native 16:9: the game camera renders the real wide view (no culled players at the edges) while the HUD keeps its 4:3 proportions; 2D screens are pillarboxed with stretched edge pixels.
• FXAA antialiasing (DirectX 11 / OpenGL) on top of supersampling (internal resolution).
• Built-in cheats: infinite game clock, infinite shot clock.
• Spanish and English UI (plus Flycast's other languages), reduced menus (Dreamcast-only options removed), Reset button.
• Online play through Flycast's GGPO rollback netcode (experimental; both players need the same build, the same romset and the same widescreen setting).

Getting started (Linux x86_64)

Download VirtuaNBA-Recomp-linux-x64.tar.gz, extract it, copy the ROM and BIOS as above, then run ./build_game.sh once (needs g++ and make: sudo apt install build-essential) and ./VirtuaNBA-Recompiled.

Releases

Pushing a tag v* runs .github/workflows/release.yml, which builds both packages (vnba/tools/package_windows.sh, vnba/tools/package_linux.sh) and publishes them as a GitHub release.

Building from source

git clone --recursive https://github.com/PocketLucho/Virtua-NBA---Recompilation
cd Virtua-NBA---Recompilation
# Windows package (engine + builder), cross-compiled from Linux:
LLVM_MINGW=/path/to/llvm-mingw-20251104-ucrt-ubuntu-22.04-x86_64 vnba/tools/package_windows.sh
# Linux package (see the script header for the apt dependencies):
vnba/tools/package_linux.sh

Other targets:

• Libretro core for testing: cmake -B build-lr -DLIBRETRO=ON && ninja -C build-lr. The headless test frontend is vnba/host/lr_headless.cpp.
• Developer build with the blocks linked in (no DLL): generate the sources (VNBA_GENERATE=<dir>, see vnba/builder/build_game.ps1) and configure with -DVNBA_AOT_DIR=<dir>.

Technical documentation: vnba/docs/TECHNICAL.md. Development log (Spanish): vnba/docs/STATUS.es.md.

Legal

• This project is licensed under the GNU GPL v2 (inherited from Flycast, see LICENSE). Flycast's original README is kept as README.flycast.md.
• It contains no copyrighted material from Sega or the NBA: no ROM, BIOS, graphics, sounds, music or translated game code. Graphics, sound and music are always read at run time from the user's own ROM; the recompiled code (vnba_game.dll) and the boot snapshot are generated locally from the user's files and must not be redistributed.
• vnba/builder/vnba_seeds.txt only lists addresses of code entry points, used to guide the decoder.
• "Virtua NBA", "SEGA", "NAOMI" and "NBA" are trademarks of their owners; they are used only to describe what this software is compatible with. This project is not affiliated with or endorsed by them.
• This is not legal advice. Dumping your own cartridge is the only way to obtain the ROM legitimately.