# Contra (J) disasm: rebuilding the Japanese NES game

> Contra (J) disasm reconstructs the Japanese NES game's program banks in assembly. Its Makefile assembles the ROM and compares its SHA3-256 checksum with the original; users provide the CHR banks from their own ROM.

- Type: Case study
- Targets: Game
- Category: Independent reconstruction cases
- Relationship: Independent reconstruction project
- Sources reviewed: 2026-11-06
- Added to the catalog: 2026-11-09
- Original resource: <https://github.com/ZReC/contraj-disasm>
- Primary source: <https://github.com/ZReC/contraj-disasm/blob/4ebc4b8ae7f810d4157caadf912d2652041df832/README.md>
- Catalog page: <https://awesomerea.org/resources/contra-j-disasm-case/>
- Record JSON: <https://awesomerea.org/resources/contra-j-disasm-case/record.json>
- Chinese version: [简体中文](https://awesomerea.org/zh/resources/contra-j-disasm-case/index.md)

## Requirements & limits

- **Prerequisites:** Supply CHR banks extracted from the specified Japanese Contra ROM.
- **Prerequisites:** Building requires asm6, a C compiler and OpenSSL for the checksum.
- **Limits:** The author calls the disassembly a first iteration.
- **License:** No licence file in the repository.

## Primary sources

1. <https://github.com/ZReC/contraj-disasm/blob/4ebc4b8ae7f810d4157caadf912d2652041df832/README.md>
2. <https://github.com/ZReC/contraj-disasm/blob/4ebc4b8ae7f810d4157caadf912d2652041df832/Makefile>

## More in Games

- [Cosmore: reconstructing Cosmo's Cosmic Adventure](https://awesomerea.org/resources/cosmore-case/index.md) · Case study
- [Crackdown 2: byte-matched Xbox 360 decompilation](https://awesomerea.org/resources/crackdown-2-decomp-case/index.md) · Case study
- [Crash Bandicoot: a matching PlayStation decompilation](https://awesomerea.org/resources/crash-bandicoot-matching-decomp-case/index.md) · Case study
- [Crash Bandicoot: The Wrath of Cortex — matching PS2 decompilation](https://awesomerea.org/resources/crash-woc-decomp/index.md) · Case study
- [Crash Bandicoot: The Wrath of Cortex: a GameCube decompilation](https://awesomerea.org/resources/crash-wrath-of-cortex-gc-decomp-case/index.md) · Case study
- [Croc: Legend of the Gobbos — a PlayStation decompilation](https://awesomerea.org/resources/croc-decomp/index.md) · Case study

## About this entry

The description was reviewed against primary sources.
Original editorial content: MIT. Linked projects, papers and assets retain their own rights and licenses.