# Rally Builder

> Rally Builder builds native Windows and Mac versions of Top Gear Rally and Boss Rally from your own ROM or CD, using byte-exact decompilations of both games.

Web page: https://emulationking.com/nintendo/n64/games/topgearrally/ports/rallybuilder/
Page updated: 2026-11-04

- Developer: Jeffrey Wilbur (Strut B)
- Port type: Decompilation (The game's code was rewritten by hand as source code that builds back into the same game, then made to run natively on PC.)
- Game: [Top Gear Rally](https://emulationking.com/nintendo/n64/games/topgearrally/index.md)
- AI use: Not stated
- Source code: /opt/buildhome/repo/content/nintendo/n64/games/topgearrally/ports/rallybuilder/index.md
- Runs on: Windows, macOS

What you need: Your own copy of the game: a Top Gear Rally ROM (the USA, European or Japanese cartridge) and, for Boss Rally, the retail Boss Rally CD as BIN/CUE. Top Gear Rally Remastered needs the USA and Japanese ROMs and the CD. Windows 10 or later (64-bit, with Vulkan or OpenGL 3.3), or macOS 12 or later on Apple silicon or Intel.

Rally Builder is the player's way into a preservation project by Jeffrey Wilbur (Strut B) that decompiles Boss Game Studios' rally games: Top Gear Rally for the N64 (1997) and Boss Rally for Windows (1999), which was built on the same engine. The Top Gear Rally decompilation is byte-exact: every one of its 572 functions compiles under the original SGI compiler to the bytes of the retail ROM, for all three cartridges. Boss Rally's decompilation is held to the same standard against the original Microsoft compiler and is still in progress.

The builder carries the games' code compiled for Windows or the Mac, without any of their data. It reads the player's own ROM or CD, checks it by MD5, and writes a game that runs natively with no emulator. Boss Rally and Top Gear Rally are faithful ports that play like the originals, with full screen, keyboard and gamepad controls and the console's own frame rate per region added.

Top Gear Rally Remastered combines both: Top Gear Rally's menus and seasons with Boss Rally's engine running the races at 60 ticks a second, plus widescreen, a choice of PC or N64 music, an FPS counter, two-player split screen and controller rumble. On a Mac it can also be built for iPhone and iPad. A Linux build is not available yet.

## How to set it up

1. Download Rally Builder for Windows or macOS and extract it.
2. Open Rally Builder and pick a game: Boss Rally, Top Gear Rally or Top Gear Rally Remastered.
3. Point it at your ROM or BIN/CUE. It checks each file's MD5 against the known dumps before building.
4. Pick a folder and press build. The result plays on its own; your original files are no longer needed. Alt+Enter (Windows) or Control-Command-F (Mac) switches to full screen.

## Latest builds

Download these from the web page: https://emulationking.com/nintendo/n64/games/topgearrally/ports/rallybuilder/#download

- for Windows: 0.98 (2026-11-03)
- for macOS: 0.98 (2026-11-03)