> i'm using forceware drivers to try it, switch to classic mode, then if i try to
> add custom resolution of 384x224 it just says "the custom res input is invalid"
> and i can't add that resolution... wtf? any workaround?

Yeah you're right it doesn't like this resolution for some reason. It used to work with older drivers, I've added this resolution before.

Mamedev Derrick Renaud did a writeup on how to do custom resolutions in a different way but now I can't find his website. Rivatuner is probably the way to go then.