Live demo.

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 VGA controller with SVGA support and Bochs VBE Extensions. This includes support for large resolutions.
• A PCI bus. This one is partly incomplete and not used by every device.
• An IDE disk controller.
• An NE2000 (8390) PCI network card.

How to build, run and embed?

• In order to build the cpu.js file, you need make and cpp (the C preprocessor). Run: make src/cpu.js.
• If you want a compressed and fast (i.e. with debug code removed) version, you need Closure Compiler. Pull the submodule using git submodule update --init --recursive closure-compiler and run make 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.
• For more details on how to customize the behaviour and interface, see docs/adapters.md.
• If you want only want to embed v86 on website you can use libv86.js. For usage, check out basic.html.

Why?

Similiar projects have been done before, but I decided to work on this as a fun project and learn something about the x86 architecture. It has grown pretty advanced and I got Linux and KolibriOS working, so there might be some actual uses.

If you build something interesting, let me know.

Compatibility

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

• Linux works pretty well. Graphical boot fails in many versions, but you mostly get a shell. The mouse is often not detected automatically.
  • Damn Small Linux (2.4 Kernel): Run with lowram and choose PS2 mouse in xsetup. Takes circa 10 minutes to boot.
  • Tinycore (3.0 kernel): udev and X fail, but you get a terminal.
  • Nanolinux works.
  • Archlinux works. Add atkbd to MODULES in /etc/mkinitcpio.conf.
• FreeDOS and Windows 1.01 run very well.
• KolibriOS works. A few applications need SSE.
• Haiku boots, but takes very long (around 30 minutes). Set the memory size to 128MB.
• ReactOS doesn't work.
• No Android version seems to work, you still get a shell.

You can get some infos on the disk images here: https://github.com/copy/v86/tree/master/images

How can I contribute?

• Add new features (hardware devices, fill holes in the CPU), fix bugs. Check out the issues section and concact me if you need help.
• Report bugs.
• Donate. Via Bitcoin: 14KBXSoewGzbQY8VoznJ5MZXGxoia8RxC9. If you want to donate elsewhere, let me know.

License

Simplified BSD License, see LICENSE, unless otherwise noted.

Credits

• Test cases via QEMU, http://wiki.qemu.org/Main_Page
• https://github.com/creationix/node-sdl
• ascii.ttf (used in node) from http://www.apollosoft.de/ASCII/indexen.htm
• Disk Images

More questions?

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

Author

Fabian Hemmer (http://copy.sh/, copy@copy.sh)