When I was interning at Apple back in the day I had a side project of porting wolf3d to OS X, and it was the first occasion I had where I came to admire John Carmack's code directly. His game source code is something I recommend checking out to coders interested in gamedev.
Also, I have fond memories of poking around making DOS experiments in Borland C++ as a teen.
But speaking of version control — I guess that's just how things were done in the 90s. I read recently that not only was Final Fantasy 7 developed and shipped without it, but Squaresoft contemporaneously lost the final PlayStation source code and art assets. The studio contracted to port it to PC was supplied with a mishmash of non-final code and assets.