MARS

What this is

In 1993 Tim J. Clarke wrote a real-time martian landscape renderer that fit in a 5649-byte DOS executable. In 2021 Wojciech Bruzda disassembled it, rewrote it, and reduced it to roughly a tenth of that size — the binary running above is assembled from that annotated source.

It draws into VGA mode 13h, reprograms the palette DAC directly, and needs 32-bit registers, so it requires a 386 or better. Rather than emulate DOS, this page boots an actual FreeDOS floppy on an emulated PC.