New to the N900 and confused somewhat. When hooking up to the PC I've learnt that on the device in x-terminal

~/MyDocs $ is where you gain access to certain files and directories here when plugged into a PC (however, some folders in that directory don't appear in X-Terminal?

But if you do

sudo gainroot

and go to /home # and I do ls to list the files and directories I see the folder opt.

I go into that folder and find some of the apps I've installed. How do I gain access to this directory when plugged into the PC?

One reason why is Mame. It can't find my legal ROMS I have. Keeps telling me to check out the mame.ini file. Which I've found in /home/opt/mame #

Once in there I'm unsure what command I type to open the .ini file. So I've ended up copying it to

/home/user/MyDocs #

And then connect it to PC so I can access the file. Still can't understand why MAME can't find the ROMs, but that's another question. More wanting to understand how you get to this seemingly hidden directories when plugged into a PC.

Any ideas?

The easiest way is to connect using Winscp Assuming your using a windows platform on your desktop)

Install Winscp on your desktop.

Install SSHserver on your N900

There are threads on here that explain in greater detail how to do this.

you use something called SSH and access your files from wireless. all you do is install a SSH server from the repos, set a password and get winscp for windows and connect to the ip and the user name is root and the password is whatever you set, if your in linux you can just click places connect to server and select SSH. if you cant connect you need to change your wifi connection to power saving off, but always remember to turn it back on.

Just install filebox file manager application and you can browse your whole file system inside of Maemo.
If you are not limited to windows proprietary file systems you could install backupmenu to access the optfs partition from your PC, while the Maemo system is not running from any ext3 capable PC or Live-CD.

damn i should install backupmenu instead of running ssh server
thanks for the idea

BackupMenu provides access to USB mass storage for all partitions, as well as USB networking and sshd starting / login. I seriously wonder why not more people know and recommend this...