Game Engine Black Book, Wolfenstein 3D
This is a really fun walkthrough of the codebase of Wolfenstein. A game where the graphics were ahead of its time, but the team refused to let that lower their ambitions. It goes into John Carmack found a way to use use integers as floating points (since there was no hardware support for floating points), how all assets were rotated 90 degrees since writing vertically was faster than horizontally, and so many other neat tricks. It's refreshing to see software written by someone who has such an understanding of the computer architecture. Fun look into the video game/graphics programming culture of the 90s, that relentlessly pursued optimizations. Recommended nerd read.