has anyone built the unreleased Casio fx-702p memory expansion module?

[blackjetrock]

I think as the schematic mentions ROM that it is probably ROM, but I suppose RAM would also work with appropriate code driving the module. I have thought about building a module for the FX702P but i don't actually have a working unit out of several that I have bought so I couldn't test it. Then there's the problem of what to put in it if it is a ROM...

Andrew