First post, by x86++
The source code is here for the Serious Engine 1: https://github.com/Croteam-official/Serious-Engine.
It is the engine which runs Serious Sam:The First Encounter and The Second Encounter:
http://www.mobygames.com/game/serious-sam-the … first-encounter
http://www.mobygames.com/game/serious-sam-the … econd-encounter
Details in the README file:
https://github.com/Croteam-official/Serious-E … aster/README.md
The README states that a recent version of Visual Studio is required. Unless the source code was heavily modified since its release date, then it should be possible to build a binary with an older version, such as VS2005. And backwards compatibility with Windows 98 and later.
Located many references to MMX code by searching for "mm0", including these files: DrawPort_RenderScene.cpp, Gfx_Direct3D_Colors.cpp, Gfx_Direct3D_Textures.cpp, Gfx_OpenGL_Textures.cpp, Graphics.cpp, TextureEffects.cpp, LayerMixer.cpp, RenderModel_View.cpp, SoundMixer.cpp.
I haven't confirmed yet, but there are lines which define where to use MMX code in TextureEffects.cpp: ASMOPT. This file has a lot of references to the "mm0" register. If the ASMOPT line is undefined, then a build of this engine should rely on the alternate C source code path. If this is true for all MMX code, then it should be possible to build the engine on non-MMX CPUs, such as the Pentium Pro; even though low framerates are expected.