A custom virtual machine for the Stars 4X game

Stars! is a classic 1995 4X game for 16-bit Windows 3.1, still enjoyable today but challenging to play on modern systems. Retro hardware or emulation like otvdm, DOSBox, or Wine is required, often paired with Wine. A new solution called Stars!VM, or Stars! Virtual Machine, offers an improved gaming experience. Stars!VM embeds a custom 80286 emulator and a Win16 to Win32 bridge, allowing the game to run seamlessly as if it were a native 32-bit or 64-bit port.

It includes the original 16-bit game compressed inside an executable, ready to play out-of-the-box without any further setup. 32-bit builds are provided, although SSE2 is required, as there's no advantage to using 64-bit in this case. The Windows bridge neutralizes copy protection, and the VM avoids dumping the Stars.ini file under C:\WINDOWS, interacting properly with the task bar, and providing better behavior compared to the original game.

The developers focused on optimizing turn generation, resulting in nearly twice the speed. The game's size has been reduced by half to 1.5MB through custom LZ-based compression. A serial code serves as copy protection, and the VM injects a fixed serial code at first run, eliminating the need for a purchased one.