Ingenious Developer Packs Solitaire Game into One Nintendo GBA e-Reader Card

In a remarkable feat, independent developer Matt Greer has showcased his technical prowess by packing an entire game of Solitaire onto a single, custom Nintendo e-Reader card. Greer shared his journey in a detailed blog post and an engaging YouTube video, unveiling how this custom card was crafted with just two “dotstrips,” each holding 2,192 bytes, bringing the total to a little over 4.3 kilobytes of data.

For a bit of context, let’s dive into the history of the Nintendo e-Reader. Released for the Game Boy Advance initially in Japan in December 2001 and then in the United States by September 2002, this nifty peripheral allowed gamers to load full games or add-ons to existing Game Boy Advance titles via scannable cards. These cards tapped into the e-Reader’s impressive 8MB of onboard storage. It was common for NES ports to extend across as many as 10 cards, although a maximum of 12 could be supported. However, sometimes only a single card was needed for simpler additions like extra levels in Super Mario Advance 4.

In a captivating video demonstration, Greer takes us through the development process of this Solitaire project. He delves deep into how he navigated the stringent technical confines inherent to Game Boy Advance gaming, making this homebrew creation a standout achievement in the already niche arena of homebrew Game Boy development. But what makes this even more extraordinary is that it’s all tucked neatly onto a single e-Reader card.

According to the blog, the e-Reader was capable of handling NES games, raw binaries, and Zilog Z80 binaries quite efficiently. In particular, the Z80 assembly language was a key player here, thanks to its minimal resource demands. Additionally, the e-Reader offered an API known as ERAPI, streamlining development by enabling the execution of commonly used tasks without redundant coding in the dotstrip, which proved vital in conserving space.

One caveat, however, was that the Z80 emulator within the e-Reader wasn’t entirely accurate, relying on a limited set of opcodes and registers. This limitation meant certain operations typically feasible on a Z80 couldn’t be performed on the e-Reader. Yet, Matt Greer managed to overcome these constraints, crafting a fully functioning Solitaire game complete with customizable music tracks, all within a mere 4,384 bytes packaged across two dotstrips on a custom e-Reader card.

Greer’s project is a testament to what can be achieved within tight technological margins. It is a bit of a shame, though, that the e-Reader’s production was short-lived, leaving it as a mostly forgotten relic in gaming history.