JarekOS

What is JarekOS?

JarekOS is an text-based operating system created by Jarek15, an Estonian
who is learning about code and how operating systems work. This OS is entirelly
built from scratch.

How to use

Run using QEMU:
qemu-system-i386 -fda jarekos.img (floppy.img for older versions)

Or use PCem with a floppy image.

Needed to run on PCem:

Processor: 386 processor or higher

RAM: 1 MB or higher

Display: CGA (But VGA is better)

Sound: Not needed, OS uses the beeps on your computer

Keyboard: Needed

Type help inside the OS to get started.

Download

Screenshots (v0.1–v0.3)

Bootscreen (v0.1)

Help menu (v0.3)

Debug tool - memory dump (v0.3)

Bad Apple demo, only a few frames (v0.3)

Hex viewer (v0.2)

Directory and executing BIN files (v0.3)

Version History

v0.3 – Input system, debug tool, bootscreen (March 21st, 2026)
v0.2 – Basic shell and commands (January 31st, 2026)
v0.1 – The beginning (December 31st, 2025)