FizzleFade
As interesting as this article is, I would also love to know where and how the author of the code learned about LFSRs!I wonder if they rediscovered the algorithm, knew they were implementing a LFSR or even just solved a particular instance of the problem without ever realizing they were writing a LFSR.I learned about LFSRs a while ago and wrote a small implementation for ruby as an exercise [1] using a Wikipedia page as reference [2]. But Wolfenstein 3D was released in 1992, I'm sure back then information was a lot harder to find online!1: https://github.com/EmmanuelOga/lfsr 
2: https://en.wikipedia.org/wiki/Linear-feedback_shift_register