"This ISA VGA card is slightly faster than other VGA cards, but the BIOS has i386-specific instructions in it, so I hacked the BIOS so that I can run my 100% rewritten in assembly-language 16-bit real-mode 8086 DOOM port on my 286 machine..." https://www.doomworld.com/forum/topic/140155-realdoom-doom-ported-to-16-bit-real-mode/?page=10&tab=comments#comment-3019156 #RealDOOM is a port of DOOM optimised for 16-bit DOS. It can achieve 486-level framerates on a 386 and about 10fps even on a 25MHz 286!! #retrocomputing #retrogaming #DOOM