WriteUp: 16 Bytes of x86 that turn Matrix rain into sound
6 hours ago
- #x86 assembly
- #algorithmic art
- #demoscene
- Released at Outline Demoparty in May 2026, an exploration of algorithmic density in 16 bytes of x86 DOS assembly.
- Code draws an infinite Sierpinski fractal by using video memory as calculation space and interprets geometry as audio data via PC speaker.
- Starts with BIOS interrupt to set video mode, initializing memory with uniform pattern (ASCII 0x20 and color 0x07).
- Uses XOR operation on memory, isolating bit planes to generate Rule 60 cellular automaton, matching Sierpinski triangle pattern.
- Outputs byte to port 61h to control PC speaker, creating square waves where fractal geometry dictates audio frequency and rhythm.
- Step size of -56 bytes (from lodsb and sub si, 57) alters traversal, affecting audio frequency (halving it) and visual layout.
- Fractal renders as 10 vertical columns of flickering glyphs on screen due to gcd calculation on screen width and step offset.
- Behavior varies with hardware/emulator due to memory state differences post-BIOS, embracing unpredictability within tight constraints.