I really love using MAME's HLSL feature... It works great on 2 of my PCs, does not work at all on 2 other PCs, and I can not figure out why. Same settings on all.
Is there something that HLSL requires?
Certain class of video card? Specific version of DirectX?
Some kind of ".net" install?
The tool tip for the HLSL option says "PS3.0 required"... I am not sure what this refers to, and doing an internet search on that returns a bunch of Sony results, of course.
I have been troubleshooting this myself for a while with no luck. Apologies if this has been addressed before.