I found this great site by John Maushammer.

This is what you can expect from the site:

Disassembler (Release 1.03)
Assembler
Simulator
VMU-PC transfer
CPU Documentation
Potato Chip Hardware (memory map)
BIOS Operation
Hardware protocols
Sample Code
Tools (new vmu animator)

He also talks about some “Future Stuff”:

Built-in source code listing (aprox. 28K) [you can read the object code from your vmu, working on source!]

FLASH programming specifications [marcus figured out how to make the built-in firmware do this, I’ve documented the low-level portion]

how to enable the 3D holographic display (maybe that’s just a vicious rumor)

He even goes on to mention something about a “VMU MP3 player”. Fact or Fiction you decide.

-Cyber Plague