Retropass

An NES password generation tool

Retropass is a library and cli tool for generating passwords for NES-era video games. Yes, there's quite a few, but I had a few goals not shared (or at least not satisfied) by existing tools:

1. Retropass is intended to support multiple games.
2. Retropass can be incorporated into other generation tools. If you like writing UI's, you don't need to get bogged down in binary to get anywhere.
3. Retropass's CLI is easily scriptable, if for whatever reason you want that.
4. Retropass ships with machine- and human- readable specifications of the password formats. It can be used as a reference when developing other programs.

Status

Still beta. CLI and API details are subject to change. The following games are supported (so far):

• Mega Man 2
• Mega Man 3
• Metroid
• Kid Icarus
• Solar Jetman
• Battle of Olympus

Installation

1. Install Python 3.6 or above.
2. Install Pip, if needed. On windows platforms, Pip is included in the python installation.
3. Run pip install --user retropass

Usage (by players)

Retropass is intended as a library for use by other tools, but it has a command line interface as well. You feed it a file containing the options you want, and it generates a password that implements those options.

retropass --help will print the available games and options.

An example, from metroid:

1. Run retropass metroid --dump > metroid.conf to create the file.
2. Edit the file to set whatever options you want.
3. Run retropass metroid --conf metroid.conf. It will print the corresponding password.
4. Enter it in your game of choice and play.

Usage (by developers)

The API is minimal. There is a Password class. It has subclasses for each game, and a .make classmethod that creates the appropriate type of object given the game's name. A list of available names is available via retropass.Password.supported_games()

The options available for a given password can be set either attribute-style (pw.option = 1) or dictionary-style (pw['option'] = 1). You can get the available options and their current settings as a dictionary with dict(pw), or as a pretty-printed string with print(pw.dump()). Stringifying or printing the password object will produce the resulting password.

Usage example:

from retropass import Password

pw = Password.make('metroid')
pw.has_marumari = 1
pw.has_longbeam = 1
print(pw)

Known Issues

• There's no great way of handling lists of related bits, e.g. all the missile containers in Metroid

Extra Credits

The following links were instrumental, either as documentation or as reference implementations. Credit for figuring out the password mechanics belongs to these people, not me:

• Metroid Password Format Guide (John Ratliff)
• True Peace in Space (Alex Rasmussen)
• Solar Jetman Password Generator (CyberN)
• Battle of Olympus Password Generator (Steven Hicks)
• Mega Man 2 Password Mechanics (StrategyWiki, multiple authors)
• Kid Icarus Password Generator (KIP) (Parasyte? (no author listed, but see archive.org)