WinROTT and the modexlib.cpp implementation

I spent the evening studying the modexlib and tracing code execution paths. I need to understand how WinROTT is addressing video memory so that I can begin the translation to Direct3D 9. The learning curve is steep. I haven't looked at video memory layouts in 15 years and I have no recollection of ModeX VGA modes.

I am working on the idea that WinROTT will render to a texture which can then be bit blitted to video memory. I've got a rendering framework put together from several examples in the Direct3D 9 SDK, but the physical format WinROTT is using for video buffers is very different from the format needed for a texture.

At the moment, the task is well defined:

1. Learn Direct3D 9
2. Understand how WinROTT is addressing video memory (i.e. how is it drawing graphics?)
3. Translate the existing WinROTT video routines to something Direct3D 9 can understand

I'm also still in the process of performing code cleanup and modernization. I'm working on some aspects of the code that can utilize threading to improve performance.