I always found it really funny that PC's had these absolute monsters of CPU's relative to the consoles of the time but because of the graphics setup they struggled to do smooth scrolling like Mario on the NES in 1985. But that weakness meant you could essentially do a lot more work per pixel on screen and thus allowed these ray casting/BSP tree systems.

So while it didn't have custom processors for sprites and background layers it meant there wasn't a rigid fixed function nature to what the PC could do.

By the mid-late 90's with dedicated 3D processor this wasn't an issue any more but there was a brief time in the early 90's where there was this wonderland of unique visual rendering.