Does the D1 have some sort of mini hard drive/permanent storage on which it stores address information? I had the battery completely disconnected from the car for a few hours while I ran the wires again through the middle of the car and when i connected it back, all my addresses ( i had keyed in only a few) were still in the address book.

However settings like the time, background image, miles to km - those were reset back to factory settings, so i had to redo those

I don't know what kind of permanent storage it has for address information, but i was so glad when i saw all that info still there!

Side note: second cool thing I discovered, is that it has something called "tracking". so for example, if your home is in a new neighbourhood which is not on the map disc - no problem. just have the tracker set on, and when you get home, set the current location as your home, and voila, when you want to come home or key in a route to a new destination from your home, the nav now has a map it can refer to - the tracking it just did to your house! I tried it and it works flawlessly!!!!

The address book is stored in NVRAM (Non-Volitale Random Access Memory)

Just like a USB Flash Drive.

Yes, after posting this I also found out that it is 64 MB. Very cool! :D