Graphics programming - thoughts on portfolio idea?

Hello I am currently learning and playing with several things in the realm of graphics programming (directx, opengl, sdl, etc...). After learning a decent amount about them I decided I wanted to do something more advanced and I came across the project idea (through goggling various things), to create a 32-BIT DOS program using C and assembly. The main goal is to have it as a portfolio piece, to create something from the ground up, to overcome it as an intellectual challenge and finally moved beyond just calling functions and procedures where necessary (as is the case with many apis and libraries out there); most programming today is just gluing stuff together unfortunately.

Is there anything I am missing or just being stupid?