Matt Greer, an independent developer, has made waves by bundling a complete game of Solitaire onto a single Nintendo e-Reader card, which he showcased in a blog post and a YouTube video. This custom card utilizes two “dotstrips” that contain 2,192 bytes each, amounting to a little over 4.3 kilobytes of data.
The Nintendo e-Reader was launched as a peripheral for the Game Boy Advance, first in Japan in December 2001 and later in the United States in September 2002. It enabled users to load full games or expansions for existing Game Boy Advance titles via scannable cards, storing them on the e-Reader’s substantial 8MB of onboard memory. This device was capable of handling games that were spread across as many as 10 cards, and even up to 12 in some cases. More compact offerings, like additional levels for Super Mario Advance 4, needed just one card to deliver new content.
In a particularly fascinating twist, Greer’s blog post delves deep into the intricate development process behind this homebrew version of Solitaire. This game stands out as it operates within what are perhaps the most stringent technical limitations associated with Game Boy Advance games. Creating homebrew games for the GBA is an intricate pursuit in itself, but fitting an entire game onto a single e-Reader card takes this to a whole new level of exclusivity.
According to Greer’s detailed post, the e-Reader is capable of loading NES games, raw binaries, and even Zilog Z80 binaries. The Z80 assembly language, known for its minimal footprint, proved useful for this project. Additionally, e-Reader apps can utilize an API called ERAPI, allowing them to perform common tasks directly via the e-Reader, reducing the need for repetitive coding in dotstrips and thereby conserving precious space.
A point of interest highlighted in Greer’s post is that the Z80 emulator within the Nintendo e-Reader isn’t fully precise. It functions with a limited set of opcodes and registers, meaning some operations feasible on a standard Z80 aren’t possible with the e-Reader’s constraints. Despite these limitations, Greer managed to craft a fully functional Solitaire game, complete with customizable music, packed tightly within just 4,384 bytes. Achieving this with two dotstrips on a single custom Nintendo e-Reader card underscores the remarkable ingenuity of homebrew developers. It’s a bit of a shame, though, that these e-Reader cards were only produced for a brief time, leaving the Nintendo e-Reader as a largely overlooked piece of gaming history.
