Matt Greer, an independent developer, recently shared a fascinating blog post and accompanying YouTube video where he showcases a unique achievement: fitting an entire game of Solitaire onto a single custom Nintendo e-Reader card. This card, impressively compact, encompasses only two “dotstrips” and contains a mere 4.3 kilobytes of data, with each strip holding 2,192 bytes.
For those unfamiliar, the Nintendo e-Reader was an innovative peripheral for the Game Boy Advance, first hitting the Japanese market in December 2001, followed by a U.S. release in September 2002. This nifty device could read scannable cards, allowing either full games or expansions to existing Game Boy Advance titles to be stored on its substantial 8MB of onboard memory. To put this in perspective, some e-Reader games required up to 10 cards for NES ports, though it could technically support up to 12. In contrast, certain features like additional levels for Super Mario Advance 4 needed just a single card.
Greer’s blog delves deeply into the development process of this homemade Solitaire game, crafted amidst possibly the most stringent technical confines imaginable for Game Boy Advance titles. Homebrew games on this platform are already a rarity, but one that fits on a single e-Reader card verges on the edge of impossibility.
According to his blog, the e-Reader has the capability to load NES titles, raw binaries, and even Zilog Z80 binaries. The low footprint of Z80 assembly language was particularly helpful for Greer’s project. Moreover, e-Reader applications leverage an e-Reader API (ERAPI), a clever tool that reduces code repetition by allowing numerous functions to be directly called from the e-Reader, thus conserving space.
Despite the Z80 emulator not being perfectly accurate and having a limited range of opcodes and registers, Greer adeptly navigated these limitations to create a fully functional Solitaire game, complete with customizable music, all squeezed into just 4,384 bytes. It’s quite remarkable how much he achieved with constrained resources, all packed onto two dot strips of a single custom Nintendo e-Reader card. It’s a bit of a shame that e-Reader cards had such a short production run, leading to this intriguing piece of gaming history being largely forgotten.
