It might be as simple as running two copies of the program but that's just me (I'll read the article later).
Mame already lets you play multiplayer "on the same machine" as it always has. But for a portable that's good news.
Set your mojob mame color in display to match your stupid ass desktop color to avoid black screen in netplay, fukaz. t(';'t -TFR, AD 2-20-02