Inspiration
I'v coded some software 3D renderer in the past. The first one was written in C for my game console. It was a very simple one that only drawn the edges of cubes, with single color.
After that, I'v coded better one in C++ with SLD2. This time, it could render in real-time multiple cubes with simples texture and player mouvements.
Finally, I'v coded antoher one in Assembly for the AVR-MicroPC. This one was verry simple, and could draw the edges of one white cube, without any rotation or texture, but with player mouvements.
It took aproximatly 1200 lines of code, but it was fast, and can run at 30FPS.