EM-DOSBox

Spec sheet

Purpose

EM-DOSBox is a DOSBox version that can be compiled with Emscripten to run DOS games and programs in a web browser.Read 5 Oct 2026 · github.com

License

The repository identifies DOSBox as distributed under the GNU General Public License and links to its GPL-2.0 license file.Read 5 Oct 2026 · github.com

Asyncify

Asyncify is enabled by default to make more DOSBox features work, with what the project describes as a very small performance penalty.Read 4 Oct 2026 · github.com

Browser features

With Asyncify enabled, users can interactively load files into DOSBox.Read 5 Oct 2026 · github.com

Browser serving

The README says to serve the page over a web server because most browsers prevent access to required files through file:// URLs.Read 5 Oct 2026 · github.com

Build limitation

Compiling in Windows is not supported because the build process requires a Unix-like environment and GNU Autotools.Read 5 Oct 2026 · github.com

Build output

The build creates dosbox.js and, when WebAssembly is enabled, dosbox.wasm, along with a simple HTML interface.Read 5 Oct 2026 · github.com

Compatibility

The project says most games run successfully in web browsers, though a few programs can have problems due to paging exceptions.Read 5 Oct 2026 · github.com

Configuration

A dosbox.conf file can be included in a package to change emulator speed, audio, or graphics settings.Read 4 Oct 2026 · github.com

Creator credit

The README credits Boris Gjenero with getting the Emscripten port working, fixing issues, and improving performance.Read 4 Oct 2026 · github.com

Credits

The project credits Boris Gjenero with getting DOSBox working through Emscripten and improving its performance for browser use.Read 5 Oct 2026 · github.com

Customization

A packaged DOSBox configuration file can change speed, audio, or graphics settings.Read 5 Oct 2026 · github.com

Dependencies

Building requires a recent stable Emscripten version, and the packager tools require Python 3.Read 5 Oct 2026 · github.com

Loading programs

The included packager tools can create web pages that load DOS files into the Emscripten file system and pass command-line arguments to DOSBox.Read 4 Oct 2026 · github.com

Packaging

The included packager tools can create web pages that load DOS files and launch a specified game or program.Read 5 Oct 2026 · github.com

Save files

Game saves go into an in-memory Emscripten file system by default and are lost when the web page is closed.Read 5 Oct 2026 · github.com

Save-file limitation

Saved games go into an in-memory Emscripten file system by default and are lost when the web page is closed.Read 4 Oct 2026 · github.com

Status

The project says it runs most games successfully in web browsers, though some programs can encounter paging exceptions.Read 4 Oct 2026 · github.com

Where Specifiction places it

• MS-DOS Emulators#24 of 266.7