Hey guys new here.
Been working with PC hardware for 25+ years, decided to go back to my roots for a play.

Now I have 2 systems here, not that old, one is a P4 which is kinda flaky, the other is a Pentium III 550E which from what I can tell works perfectly.
But I seem to be having a problem running only Duke 3D, Blood and Shadow Warrior in dos.
Everything else runs fine, Quake (DOS), GLQuake, Quake III, Unreal, Unreal Tournament, heck even Commander Keen

Specs are:
P3 550Mhz
DFI CA61 Motherboard
512MB Ram (2x 256MB)
Geforce 3 Ti 200
40GB Hard drive partitioned
Soundblaster PCI
Windows 98se.

This is what happens everytime I run anything based on the Duke3D engine, this is even with no sound card selected, 320x200 and straight dos mode:

This does not happen on the P4 at all, but it has a bad cache problem so it randomly boots, hangs or bluescreens, waiting on replacement parts.

Has anyone see this problem before, I've tried with just a single stick of ram, could it be a hardware problem with the P3 too

Thanks.