New Version Of The DOS Emulator DSx86

November 23, 2009 by Hawq

A DOS emulator for the Nintendo DS, its a new one so let’s see what the author had to say about it:

Currently DSx86 emulates the following:

80186 processor (which is actually a 80286 processor without the protected mode stuff)
MCGA graphics adapter (a stripped-down VGA with a maximum resolution of 320×200)
SoundBlaster (including AdLib-compatible FM sounds) sound card
83-key US keyboard

DSx86_LW2 is a technical demonstration of my PC emulator for Nintendo DS. Since the actual emulator is still very limited in the opcodes, DOS calls and hardware it can support, I can not release a version that would allow you to test any DOS program on it (as with a 99.9% probability they wouldn’t work). The only two programs my emulator currently runs are Wing Commander 2 by Origin, and my own old DOS game LineWars II. Of course Wing Commander 2 is copyrighted material so I can not include it, and since releasing a demo that does nothing useful unless you have purchased a certain game nearly 20 years ago is not very smart, I’ll release the demo version bundled with my LW2.

The size of the nds file is about 627 kilobytes, of which 224 kilobytes is taken by LineWars II (11 KB for the LW2.COM loader and 214KB by the LW2R.DAT data file), and the rest by the emulator core itself.

The demo begins at the start of the LW2.COM code inside an inbuilt x86 debugger. You can run it either by pressing the B button on your Nintendo DS, or by using the touchpad and clicking on the G on the low left corner followed by the v symbol (meaning “Enter”). When the demo starts, use the shoulder L and R buttons to scroll the screen, so that you can see the whole 320×200 graphics screen or the 80×25 text screen. One interesting info you might want to check out is the framerate counter on the right bottom of the LineWars II game screen (after you have launched into a game).

Feel free to play around in the debugger if you wish, and you can also break into the debugger at any time when the game is running by clicking on the Close (X) button on the virtual keyboard in the touchpad. Please note, though, the inbuilt debugger is meant just for my development aid, and therefore is read-only and not very feature-rich.

If the demo breaks into the debugger by itself, it means it ran into an opcode that is not yet supported. There is no way to continue after this has happened, so just reboot and start over.