Doom was originally designed in 1993 for 32-bit DOS computers with 4 MB of RAM. It’s mostly written in C code with very little assembly code. It has been ported to all kinds of systems. Usually these systems are 32-bit or more and have a flat memory model.
Doom8088 is a port for PCs with a 16-bit processor like an 8088 or a 286, and with VGA or MCGA graphics.
This video shows Doom8088 running in 86box emulating a 286 @ 25 MHz.
Download Doom8088 from