X-87 – DOS 256 bytes

X-87 is a 256-byte DOS graphics program for 386-or-newer PCs, created for Outline 2026. It uses x86 and x87 floating-point instructions in real mode to generate a 640-by-400, 32-bit-color landscape: oscillating calculations place pixels into a barren scene with a dark sky, ground, and an incidental moon-like shape. Color is built up through brightness-dependent increments, giving the image a dithered appearance. The result grew from p5.js experiments begun in 2021; after the idea was reshaped into a landscape, its composition emerged largely through iterative adjustments to oscillators and scaling.

The creator describes compressing the design into the strict 256-byte limit over two weeks. A Forth prototype helped translate the drawing logic into x87, followed by a grayscale DOS version and rounds of optimization to make room for color. Further savings came from overlapping data, packing color increments, reducing floating-point operations, and combining loops. Compatibility work addressed uninitialized state, VESA memory banking, and visual artifacts that appeared especially strongly in Bochs; the final version was tested with Bochs and FreeDOS, though not on physical hardware. Rendering is slow - about 13 minutes in DOSBox at default settings, or roughly two minutes at higher cycle counts. The author considers the result close to the prototype but questions whether 32-bit color is necessary, and notes that resolution changes affect brightness, density, and artifact visibility.