[pizza234]

Plugging a DOS game to an SDL(2) library won't "just work".

Some concepts are inherent to the hardware and the O/S.

Hardware example: EGA (not the case of doom, but of other, slightly older games) uses bitplanes, it's not just an array of byes; audio cards used specific drivers.

O/S: timers may need to be emulated, as the game may not have a straightforward game loop; due to this, even exiting cleanly may not be trivial to implement.

[anthk]

Not an issue for Q1, it wasn't for neither EGA or VGA for DOS exclusivelly, they had DOS, Windows and Unix versions since day 1.