Ingenious Developer Packs Solitaire Game onto a Single Nintendo GBA e-Reader Card

Matt Greer, an indie game developer, has just dropped some fascinating news through a blog post and a YouTube video. He managed to squeeze a full game of Solitaire onto a single custom Nintendo e-Reader card. Believe it or not, the whole game fits on two “dotstrips,” each holding 2,192 bytes, making the total data size just a little over 4.3 kilobytes.

For those who might not be familiar, the Nintendo e-Reader is a neat little gadget that first came out for the Game Boy Advance in Japan in December 2001 and hit the U.S. the following September. This peripheral allowed players to scan cards to load entire games or add-ons for existing titles. It’s kind of wild that some NES ports needed up to 10 cards, and the system could handle as many as 12 cards total. On the simpler side, bonus levels for games like Super Mario Advance 4 required just one card.

In his blog post, Greer dives deep into the nitty-gritty of developing this homebrew Solitaire game. It’s no small feat, especially considering he had to work within what might be the toughest technical constraints for Game Boy Advance games. Homebrew games for this console are already quite a niche interest, but creating one for a single e-Reader card takes things to a whole new level.

According to the blog post, the e-Reader can handle NES games, raw binaries, and Zilog Z80 binaries. The Z80’s small footprint made it perfect for this project. Plus, apps on the e-Reader benefit from an API (ERAPI) that lets developers perform many common operations without clogging up dotstrip code, saving valuable space.

Greer’s write-up also reveals that the Nintendo e-Reader’s Z80 emulator isn’t perfect. It’s got a limited set of opcodes and registers, which means not everything possible on a typical Z80 can be done here. Nevertheless, under these strict conditions, Greer pulled off a remarkable feat by fitting a playable and music-customizable game of Solitaire into just 4,384 bytes. This achievement, spread across two dotstrips on a single custom e-Reader card, showcases the incredible creativity and skill within the homebrew community. It’s a bit of a shame that e-Reader cards were only around for a short while, making this a forgotten gem in Nintendo’s history.