An NES ROM hacking tool.

Corey Prophitt 0c4499b6bf Fixed a typo 4 years ago
nes cbf4714818 Added remaining mapper examples 5 years ago
screenshots c2491f6d9a Updated screenshot to use the PyPi package 5 years ago
.gitignore a06a9cdf94 Added initial .gitignore 5 years ago
.travis.yml e8c7b9d81a Added a Travis CI configuration file 5 years ago
Makefile 621290c24f Added initial makefile 5 years ago 0c4499b6bf Fixed a typo 4 years ago
nesi a71a375f20 Added --version flag to nesi 5 years ago
pylintrc 3004c46ade Added default pylintrc 5 years ago
setup.cfg c3ca421948 Added pypi setup files 5 years ago 836807af8f Updated docstring with release notes 5 years ago


BuildStatus PyPI version

A rom hacking tool for the analysis of .nes rom images.

Nesi may be useful for rom hackers or emulator developers. The file utility on Linux provides some information on .nes rom files, but not enough. Nesi was created to provide additional information.

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  1. Python 2.7 or Python 3.0+ should suffice


The easiest way to install nesi is via PyPi, this can be done with the following command:

$ pip install nesi

Note, sudo may or may not be required depending on your environment.

The second way to install is by cloning the repository and installing the development version of the pip package:

$ git clone
$ cd nesi
$ make install

The pip package installs the nesi executable as well as the nes package which can be used to write your own scripts.

Note, you may have to source your shell for the nesi executable to be picked up.


Nesi is a command line application. The basic usage can be found below:

usage: nesi [-h] [-r ROM] [-v]

Specify a .nes rom image to be analyzed

optional arguments:
  -h, --help         show this help message and exit
  -r ROM, --rom ROM  path to a .nes rom image to be analyzed
  -v, --version      show the current nesi version


A rom hacking tool for the analysis of .nes rom images.
Copyright (C) 2015, Corey Prophitt.

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <>.