I have such device. It works with natural mpio firmware, but i think i will be more powerfull with Rockbox. I don`t find any information about such port (for MPIO). So may be i can help to do this... I`m not a programmer or any thing like this

, but i can send hi-res digital photos of the
circuit boards, so Rockbox developer can find out what chips it is made of.
p.s. sorry for my english, i`m from russia so it can be some mistakes in text
