Doom was written mainly in C but the important bits like the span rasterization for the DOS version were written in assembly. The released code was for the Linu

Doom was written mainly in C but the important bits like the span rasterization for the DOS version were written in assembly. The released code was for the Linux version that didn't use assembly so the DOS was only as part of a README file[0]. The sound code was licensed (and thus never released to the public) and most likely also used assembly as that was common at the time. Quake also used assembly for a few bits (also, like Doom, had C versions for portability). That is what i meant when i wrote "use assembly", not to write the entire game in assembly (which is why i also gave my maze renderer as an example - pretty much all of it was in C except a tiny part). [0] https://github.com/id-Software/DOOM/blob/master/linuxdoom-1.10/README.asm https://github.com/id-Software/DOOM/blob/master/linuxdoom-1....