i know this is a old thread but i explain about FWMB
FWMB is an interesting board on E10/E100 series nc units.
meaing of FWMB is Factory Window Main Board
i think it emulates Windows OS on nc unit (it is not real Windows OS)
Okuma uses this board betwwen U100 and P100 and they used real Windows OS after P100 series machines.