Supposedly its all maps, maps and more maps, the gracenote database, the windows mobile operating system, and whatever other files are needed for operation. There most likely is plenty of free space on there, but i guess that might be needed for future updates.
Im not totaly sure, but i think also all of the used data is stored onto that partition of the drive, except for the music lybrary which is in a separate partition.
Some people on avic411 are trying to figure out the HD, how it can be modified and upgraded, looks like they have made great progress.
Oh by the way the flashing circuit that unlocks teh nav doest work for me
, which totaly sucks, i got a July 2006 build, and aparantly that bypass was fixed somewhere in july. im praying for some smart fella to figure out another way to unlock the nav, fo i dont have to pull over to enter a new adress.
oh an also, does anyone else get a "pop" through the speakers when turning on onstar, right aster you press the button, and everything else after that is normal?