rust_dos VS abrash-black-book

You do not need segment registers much if you stick to the tiny model. Here is someone compiling Rust to a 16-bit DOS COM executable:

https://github.com/o8vm/rust_dos

Not sure what the approach would be for them to expand that to support segments.

In DJGPP there are macros to allow your protected mode application access physical real-mode addresses (like when you want to write to video RAM). I don't know if IA-16 also does something like that, or if they added far/near keywords to the language like old 16-bit C compilers did (at least the ones I used).

Free Pascal has helper-functions to work with segment+offset pointer pairs, also without having to modify the language itself. I think that would work well enough in C, but I guess the old method of adding non-standard keywords was seen as slightly more convenient.

Demo: https://github.com/o8vm/rust_dos

It is probably possible for almost any old platform with some cross-compilation magic, but not anything that will be officially supported as the compiler-makers focus on modern systems. There is for instance an unofficial 16-bit DOS backend for GCC and at least one or two projects to compile Rust to DOS-executables (that I assume use Clang?) (in addition to 32-bit DJGPP(gcc) for MSDOS that I linked to above). Probably are similar projects to target 68k somewhere?

Michael Abrash's Graphic Programming Black Book

[Michael Abrash's Black Graphics Programming Black Book from 1997 is a fantastic book I wish I had back then. It is available for free on GitHub. I read it maybe in 2015 and I thought it was fantastic even if it is dated now. It goes through the evolution of PC hardware (CPU and graphics cards in particular) from the very first IBM PC to the mid-90's pentiums, and the last chapter or two are about the author's work on Quake.

Also available in eReader formats: https://github.com/jagregory/abrash-black-book/releases

Also look at the source for original Quake (https://github.com/id-Software/Quake), one of the last pure software-rasterizing AAA 3D PC games. Michael Abrash's Graphics Programming Black Book (https://github.com/jagregory/abrash-black-book) explains many of the critical parts of the rendering pipeline.

By the way, quake.exe for DOS was 404,480 bytes.

It's also THICK. I have my copy of the 5th edition right here, and it's about 3 inches from cover to cover. Thicker than Introduction to Algorithms and thicker than the Graphics Programming Black Book.

Read Michael Abrash's Graphics Programming Black Book for the story of how the original Quake came to life. You'll get an appreciation for John Carmack's ability to thoroughly research widely varying solutions to a problem, quickly create production-quality implementations of the promising ones, and even more quickly abandon the dead ends. The result is this almost boring, seemingly linear progression toward a final product that seems obvious in hindsight, yet it represents a leap forward the way Quake did in the mid-1990s compared to other FPSes at the time. I don't know many other public stories of individual engineers who can span both the very cutting edge of research and the practicalities of shipping real commercial software.

https://github.com/jagregory/abrash-black-book

The Abrash black book is on github!

Go through Michael Abrash's Graphics Programming Black Book to see how it used to be on PC world.