**BlackMatrixOS** is a minimalist, monolithic operating system kernel engineered entirely in pure C and NASM assembly for the x86 architecture. Designed as an educational deep-dive into low-level systems programming, it implements a complete boot-to-shell workflow within a single binary image. The system features a dual-stage boot process: a 16-bit real-mode bootloader that handles disk I/O, A20 gate enabling, GDT setup, and protected-mode transition, followed by a 32-bit kernel providing hardware abstraction for VGA text/framebuffer output, PS/2 keyboard polling, and basic PCI enumeration. Its interactive CLI shell supports 15+ built-in commands (`help`, `clear`, `echo`, `mem`, `lspci`, `reboot`), while a primitive GUI mode demonstrates VGA Mode 13h framebuffer rendering with window-like compositing. Advanced visual effects include a computationally efficient "Matrix rain" animation rendered directly to the text buffer. The kernel employs a flat memory model, explicit resource lifecycle management, and zero external dependencies—compiling to a compact ~50 KB image bootable via QEMU or physical hardware. With strict ANSI C compliance, deterministic interrupt-free I/O via port-mapped polling, and comprehensive inline documentation, BlackMatrixOS serves as both a functional reference implementation and a pedagogical tool for understanding bootloaders, protected mode, VGA programming, and kernel architecture. Licensed under MIT, the project invites exploration, modification, and extension by OS enthusiasts and computer science students seeking hands-on experience with bare-metal x86 development. 🔧💻⚙️

blackmatrixos

BlackMatrixOS is a minimalist, monolithic operating system

BlackMatrixOS is a minimalist, monolithic operating system