em-dosbox and 50 gifts for the new year

Some things only get better over the years. For example, classic games developed in the DOS era are fascinating. Each of them is a piece product made with great love. Unfortunately, the DOS platform is a thing of the past and wonderful products are leaving with it. To return them to the modern world - is this not a real gift?


How? Very simple! An interested reader, of course, remembers the emscripten project, thanks to which C ++ code can be converted to JavaScript to work in the browser. It was with his help that the games DOOM, Dune 2, TTD, X-COM and many others were adapted for the browser. However, this path is long and difficult. One project can take up to six months. And if you want everything at once? Is there any other way?

em-dosbox

There is another way - use DosBox. Indeed, why port each project individually, when you can port the entire DOS platform (to be precise, the MS-DOS emulator). This ingenious idea was embodied by Boris Gjenero in the em-dosbox project . This is the DosBox port in JavaScript made using emscripten.

So, now I will tell you how to transfer "almost any" DOS program to the browser.

Ingredients:

• Browser
• em-dosbox (dosbox.js)
• The program works correctly in DosBox

During operation, the browser downloads dosbox.js and a data packet with the program (usually a binary file with a packed directory of the source program). The dosbox.js script is nothing more than a DosBox ported to JavaScript; when executed, it emulates the DOS platform with a program running in it.

Compiling dosbox.js

Everything is simple. We clone the em-dosbox repository and compile using autotools and make

git clone https://github.com/dreamlayers/em-dosbox.git
cd em-dosbox
./configure
make

If successful, dosbox.html and dosbox.js will appear in the src folder

Program packaging

em-dosbox comes with a script that allows you to pack the directory with the program into a binary file, which can be used in conjunction with dosbox.js. For example, to get a batch file for a Dune 2 game, just do:

#python src/packager.py <имя пакета> <путь до директории> <исполняемый файл>
python src/packager.py dune2 ~/dune2 dune2.exe

If successful, the dune2.html and dune2.data files will be created . The HTML file is created using the dosbox.html template (recall, it lies in the src folder ).

Launch

So we have three files:

• program.html
• program.data
• dosbox.js

By placing them on the server we can run the program in a browser.

Happy New Year.
50 New Year's gifts.