MikeOS - simple x86 assembly language operating system

x86 operating system

MikeOS is an operating system for x86 PCs, written in assembly language. It is a learning tool to show how simple 16-bit, real-mode OSes work, with well-commented code and extensive documentation. Features:

A text-mode dialog and menu-driven interface
Boots from a floppy disk, CD-ROM or USB key
Over 60 system calls for use by third-party programs
File manager, text editor, image viewer, games...
Includes a BASIC interpreter with 46 instructions
PC speaker sound and serial terminal connection

The code is completely open source (under a BSD-like license), and is written by Mike Saunders and other developers.

News

21 Dec 2014: MikeOS 4.5 released -- Lots of new features, including a Forth interpreter. See the changelog for all the details.

10 Jun 2014: Moved to SourceForge -- BerliOS has closed down, so MikeOS has moved to SourceForge. Please update your links!

28 Oct 2013: MikeOS mouse library released -- Joshua Beck has implemented his TachyonOS mouse code as a MikeOS library. See the Downloads section below.

22 Jun 2013: First-steps guide updated -- The guide to making your own simple bootloader OS has been updated with a link to Windows build instructions.

23 Mar 2013: MikeOS 4.4 released -- Sudoku, Cosmic Flight, new BASIC features and much more.

1 Mar 2013: New TachyonOS project -- A very cool MikeOS spin-off with lots of experimental new features. Click here for the website.

Downloads

The link below contains the source code (see the source and programs directories), along with disk images for floppies/USB keys and CD-Rs in the disk_images folder.

You can write the images to a floppy disk, USB key or CD-R and boot your PC from them to test -- or use a PC emulator such as QEMU, VirtualBox or VMware. See the User Handbook below for a guide. System requirements: minimum 386 PC with a keyboard and 1MB of RAM.

MikeOS 4.5 -- zip file (406K)

Here are some contributed add-on programs:

Joshua's MikeBASIC apps -- Visualizer, Calculator, Memory Manipulator, MikeBASIC++ dev kit and more
Mouse library -- Add mouse support to MikeOS programs

MikeOS C library (84K) -- Write programs in C (see ReadMe.txt)
MikeOS Xfer (68K) -- Xmodem file uploader (see Xfer.htm)
BFM file manager -- With editor and viewer, by Ondrej Cerman
BIN2POKE -- Convert .bin files to BASIC POKE routines, from Paulo Valongo

And projects that use MikeOS:

Analogue to Digital Converter (244K) -- Project for kids
Test Card Generator (17K) -- Basic engineering tool (see README.TXT)
Monitor alignment tool (14K) -- Written in MikeOS BASIC
Arduino project (216K) -- Arduino Diecimila board access using MikeOS
USB keyboard project (585K) -- USB KB I/O project/guidelines

MikeOS downloads (since version 1.0) as of 21 Dec 2014: 65,812

Images

Click on the thumbnails below to see full-size versions.

Handbooks

These four Handbooks provide the complete documentation for MikeOS:

User Handbook -- Running MikeOS and programs

BASIC App Developer Handbook -- Writing MikeOS software in BASIC
Assembly App Developer Handbook -- Writing MikeOS software in assembly language
System Developer Handbook -- Modifying and building the OS

Note that the Handbooks are also included with MikeOS, in the doc directory. If you're new to the world of OS development, see our guide: write a simple assembly language operating system from scratch (Serbo-Croat translation).

Discussion

To discuss MikeOS and similar 16-bit real mode operating systems, join us on Google Groups.

Credits

Project admin

Mike Saunders -- main code and Handbooks

Development

E Dehling
Ian Seyler
Joshua Beck
Justin Tokarchuk
Matej Horvat
Michael van Tellingen
Mike Gonta
Peter Nemeth
Paulo Valongo
Takayoshi Sasano
Tomasz Gorol
Tslil Clingman
Walt Nagel
Yutaka Saiko

Website, docs and artwork

Nitin Reddy Katkam -- logo and site design
Paul Sommers -- Handbook API reference
Helen Ewart -- MikeOS cat mascot

Some website artwork from the Tango icon set.