Matt Greer, an independent developer with a knack for creativity, recently shared a fascinating blog post and YouTube video. He accomplished something quite remarkable: fitting an entire game of Solitaire onto a single custom Nintendo e-Reader card. This card holds two “dotstrips,” each containing 2,192 bytes, adding up to just over 4.3 kilobytes of data.
For those unfamiliar, the Nintendo e-Reader is an intriguing peripheral that first debuted in Japan in December 2001 and later hit the U.S. markets in September 2002. It was designed for the Game Boy Advance, allowing users to scan cards that could either contain entire games or add-ons for existing Game Boy Advance games. The e-Reader itself boasted a hefty 8MB of storage. Interestingly, earlier titles, especially NES ports, often required multiple cards—up to 10 per game, though the device could handle as many as 12 cards. In contrast, certain features, like the additional levels for Super Mario Advance 4, managed with just a single card.
In his blog post, Greer delves deep into the journey of creating this Solitaire game—a true feat given the severe technical limitations posed by the Game Boy Advance platform. While homebrew Game Boy Advance games are rare on their own, crafting a game for just one e-Reader card takes it to a whole new, almost surreal level of niche development.
The e-Reader’s capabilities were quite versatile, supporting NES games, raw binaries, and even Zilog Z80 binaries. The use of Z80 assembly, known for its efficient footprint, turned out to be particularly advantageous for Greer’s project. Moreover, e-Reader applications benefited from the e-Reader API (ERAPI), which simplified many common tasks by calling them directly from the e-Reader, thus saving even more space.
Matt Greer’s blog also highlights a fascinating technical challenge: the Z80 emulator embedded within the Nintendo e-Reader isn’t fully accurate and only recognizes a limited set of opcodes and registers. This constraint means some typical Z80 operations are off the table when working with the e-Reader’s restricted setup. Yet, despite these hurdles, Greer succeeded in developing a complete Solitaire game—complete with changeable music—within the tight confines of 4,384 bytes spread across a single custom e-Reader card.
It’s truly awe-inspiring what a dedicated homebrew developer like Greer can achieve. It’s a bit of a shame, though, that e-Reader cards had such a brief production run, leading the Nintendo e-Reader to become a largely forgotten piece of gaming history.
