Here is a few things, I did not mention in the original README file:
- format your MS as FAT32 (not FAT)- you'll be able to put much more map data on it
- if you use it with GPS receiver, make sure that UMD drive is empty and WIFI switch is OFF
- you can delete large maps much faster if you move all other apps out and format the MS
- use in7ane's visual tool to get maps and POIs
- you can generate maps with negative zoom value with some services,but check the preview to make sure the data is available for your area first.
-you can delete some zoom levels to save space by deleting Nx folders inside your map's folder. You cannot wipeout the 1x (base) zoom folder though.