Build Eternity 3.40 on DOS

Building MBF and Boom, I decided to build Eternity 3.40.00 on DOS.

(I simply had seen DOS support in the source, so that's why I want this)

I have '97 ver of DJGPP and Allegro 3.0

So, what I have to do?

https://doomwiki.org/wiki/Eternity_Engine

Wiki states:

Quote

Runs under Windows (95 through 10 x86 & x64), Linux (x86, x86-64, and ARM), BSD OSes, and macOS.

Which implies that DOS is not supported.

 Eternity 3.31 beta supported DOS and hail-to-the-ryzen compiled several later versions @vogons.

 That's the thread that originated ZDoom LE.

https://www.vogons.org/viewtopic.php?f=5&t=52045&start=60#p578896

You would need a much later port of GCC to DOS in order to stand a chance of porting EE back to it at this point; we use C++11 language features.