Doom used fixed point math, not floating point math. It didn't run well on a 386 SX simply because 386 SXs were slow, but it would run without FPU emulation, an

Doom used fixed point math, not floating point math. It didn't run well on a 386 SX simply because 386 SXs were slow, but it would run without FPU emulation, and at better than 1 FPS.