A programmer wrote a fully playable DOS solitaire game that fits in 3 KB, small enough to be stored in a printed QR code and loaded onto a compatible PC.
Retro-computing developer ClassicBits has written TinySol, a fully playable Klondike solitaire game for DOS-based PCs, in an assembly-language binary with a 3 KB build, while a smaller 2.2 KB version was printed as a QR code. The game was demonstrated by YouTube channel Lazy Game Reviews (LGR) at the Vintage Computer Festival Southwest 2026, where TinySol was also distributed on floppy-disk sleeves carrying the QR code. Hackaday later reported on the project.
The core 3 KB build is written entirely in hand-coded x86 assembly, giving the programmer direct control over processor instructions and memory usage without relying on a high-level language or external software libraries. This approach helps keep the game within its small memory footprint, but requires more development effort than using a modern programming language. TinySol automatically detects the available graphics hardware and supports CGA, EGA and VGA display modes, including the non-standard 640 × 400-pixel mode used on the AT&T 6300 PC.
The minimal keyboard-only build fits in 3 KB, while a fuller 3.5 KB version adds save-and-load functionality and mouse support. Both versions include automatic win detection, an auto-finish feature that completes a won game automatically, and full scoring. According to ClassicBits, the game targets hardware as old as the IBM 5150, the original IBM PC.
TinySol’s compact size allows the game to fit within a QR code, making it possible to represent the software as a printed image. The project was also distributed as physical floppy disks at the Vintage Computer Festival Southwest 2026, while the game is available for download from the ClassicBits website.
ClassicBits distributed physical floppy disks containing TinySol at the Vintage Computer Festival Southwest 2026, with the project also made available for download afterwards. Running the game requires DOS or a DOS-compatible emulator on a PC. TinySol was tested in DOSBox during development, with its CGA, EGA and VGA modes working in the emulator, although the AT&T 6300 640 × 400 mode is not supported. This allows the game to be tried on a modern computer without requiring vintage hardware.
TinySol demonstrates how much can be achieved within a few kilobytes when a programmer works directly with processor instructions and memory. Its compact assembly-language implementation also shows the trade-off between extreme size optimisation and the development effort required to build software at this level.
