Skip to content
x86 virtualization in JavaScript, running in your browser and NodeJS
Branch: master
Clone or download
Type Name Latest commit message Commit time
Failed to load latest commit information.
bios Update bochs bios Dec 13, 2017
docs Fixing broken links in docs/ Feb 22, 2018
examples Remove trailing whitespace Jan 1, 2016
lib Port filesystem changes from jor1k Feb 14, 2018
src Fix #271 Feb 23, 2019
tests Implement instructions commiss & ucomiss Oct 1, 2018
.editorconfig Only use vga color linked list for small changes Jan 23, 2018
.gitignore Minor: Newline at end of file Feb 14, 2018 ACPI test for travis Jan 24, 2018 Add kvm-unit-test to travis CI (#129) May 1, 2017 Update test scripts Jun 20, 2017 Update test scripts Jun 20, 2017 Add kvm-unit-test to travis CI (#129) May 1, 2017
.travis.yml ACPI test for travis Jan 24, 2018
LICENSE Update copyright year to 2018 Jan 2, 2018
Makefile Fix readme Feb 15, 2018
debug.html Fix keyboard on ios, fixes #105 Nov 9, 2017
package.json Simple initial package.json Nov 6, 2015
v86.css Fix keyboard on ios, fixes #105 Nov 9, 2017

Join the chat at


API examples

Using v86 for your own purposes is as easy as:

var emulator = new V86Starter({
    screen_container: document.getElementById("screen_container"),
    bios: {
        url: "../../bios/seabios.bin",
    vga_bios: {
        url: "../../bios/vgabios.bin",
    cdrom: {
        url: "../../images/linux.iso",
    autostart: true,

See API.

How does it work?

v86 emulates an x86-compatible CPU and hardware. Here's a list of emulated hardware:

  • An x86 compatible CPU. The instruction set is around Pentium 1 level. Some features are missing, more specifically:
    • Task gates, far calls in protected mode
    • 16 bit protected mode features
    • Single stepping
    • MMX, SSE
    • A bunch of FPU instructions
    • Some exceptions
  • A floating point unit (FPU). Calculations are done with JavaScript's double precision numbers (64 bit), so they are not as precise as calculations on a real FPU (80 bit).
  • A floppy disk controller (8272A).
  • An 8042 Keyboard Controller, PS2. With mouse support.
  • An 8254 Programmable Interval Timer (PIT).
  • An 8259 Programmable Interrupt Controller (PIC).
  • A CMOS Real Time Clock (RTC).
  • A generic VGA card with SVGA support and Bochs VBE Extensions.
  • A PCI bus. This one is partly incomplete and not used by every device.
  • An IDE disk controller.
  • An NE2000 (8390) PCI network card.
  • A virtio filesystem.
  • A SoundBlaster 16 sound card.


The disk images are not included in this repository. You can download them directly from the website using:

wget -P images/{linux.iso,linux3.iso,kolibri.img,windows101.img,os8.dsk,freedos722.img,openbsd.img}.

A testsuite is available in tests/full/. Run it using node tests/full/run.js.

How to build, run and embed?

  • Building is only necessary for releases, open debug.html and everything should load out of the box
  • If you want a compressed and fast (i.e. with debug code removed) version, you need Closure Compiler. Download it as shown below and run make build/v86_all.js.
  • ROM and disk images are loaded via XHR, so if you want to try out index.html locally, make sure to serve it from a local webserver. You can use make run to serve the files using Python's SimpleHTTPServer.
  • If you only want to embed v86 in a webpage you can use libv86.js. For usage, check out the API and examples.
  • A couple of disk images are provided for testing. You can check them out using wget -P images/{linux.iso,linux3.iso,kolibri.img,windows101.img,os8.dsk,freedos722.img,openbsd.img}.

Short summary:

# grab the main repo
git clone && cd v86

# grab the disk images
wget -P images/{linux.iso,linux3.iso,kolibri.img,windows101.img,os8.dsk,freedos722.img,openbsd.img}

# grab closure compiler
wget -P closure-compiler
unzip -d closure-compiler closure-compiler/ *.jar

# build the library
make build/libv86.js

# run the tests


Here's an overview of the operating systems supported in v86:

  • Linux works pretty well.
    • Tinycore (3.16, 4.8 kernel): Works.
    • Nanolinux works.
    • Archlinux works with some caveats. See
    • Damn Small Linux (2.4 Kernel): Doesn't work.
  • ReactOS works.
  • FreeDOS, Windows 1.01 and MS-DOS run very well.
  • KolibriOS works. A few applications need SSE.
  • Haiku boots, but takes very long (around 30 minutes).
  • No Android version seems to work, you still get a shell.
  • Windows 1, 3, 95 and 98 work. Windows XP is unstable, but can work with some tweaks (see this issue). Other versions might work but haven't been tested.
  • Many hobby operating systems work.
  • FreeBSD works.
  • OS/2 doesn't work.

You can get some infos on the disk images here: The Windows images are from WinWorld.

How can I contribute?

  • Add new features (hardware devices, fill holes in the CPU), fix bugs. Check out the issues section and contact me if you need help.
  • Report bugs.
  • If you want to donate, let me know.



More questions?

Shoot me an email to Please don't tell about bugs via mail, create a bug report on GitHub instead.


Fabian Hemmer (,

You can’t perform that action at this time.