Welcome to Tonc, a guide to Game Boy Advance programming originally published in 2004.

You are reading a new, revamped version of it, powered by mdbook and now maintained by the community.

Work In Progress notice

We recently finished the porting of this book. Improvements ongoing, if you spot any problems please feel free to ask for help or get involved!


This book is open source, released under the CC-BY-NC-SA license. Everyone is welcome to help, provide feedback and propose additions or improvements. The git repository is hosted at, where you can learn more about how you can help, find detailed contribution guidelines and procedures, file Issues and send Pull Requests.

More resources about GBA development can be found at There is also a Discord chat dedicated to the gbadev community.


Jasper “cearn” Vijn is the original author, creating and maintaining Tonc till 2013.

exelotl, avivace, PinoBatch, copyrat90, LunarLambda, gwilymk, mtthgn, and djedditt ported the contents to markdown and migrated the underlying rendering technology to mdbook.

Using this document

In the top navigation bar, you will find a series of icons.

By clicking on the icon you will toggle an interactive table of contents to navigate the document. You can also use and keys on your keyboard to go to the following and previous page.

The lets you choose among 6 different themes and color schemes to please your reading experience, including the classic Tonc theme.

You can search anywhere by pressing s on your keyboard or clicking the icon.

The icon allows you to suggest an edit on the current page by directly opening the source file in the git repository.

This document version was produced from git commit 6755f3 (2024-07-04 19:26:56 -0400 ).