Welcome to TreeOS! This is a very simple, hacky, but working, "demo" that draws a spinning Christmas tree and a small message while running on bare PC hardware (no underlying operating system), using only standard VGA hardware. Merry Christmas!
This demo is a bootable floppy disk. it is pure 16-bit code, and uses the BIOS to load data from the boot disk and change the video mode, before operating directly on the VGA framebuffer. It uses a standard 320x200 256-color mode (VGA mode 13h). This should work on any reasonable PC hardware at all, though I've only tested it on a virtual machine (QEMU).
You will need nasm to assemble. If you have nasm and qemu installed, you
should be able to just make qemu on Linux. E.g., on Ubuntu:
apt install nasm qemu-system-x86
cd treeos/
make qemu
Released under GNU GPL v3+. Copyright (c) 2019 by Chris Fallin <cfallin@c1f.net>.