Extra memory how can access for new maps

I did this on my 260 before updating to the 2009 maps. I copied this process from another thread and I don't remember who posted it to give them credit....but here goes.

Make a copy of your current GMAPPROM.IMG (containing the V2008 maps....(I assume you could copy the same file from the 2009 maps), as GMAPSUPP.IMG on an SD card.

Create a file called GMAPSUPP.UNL on the card using notepad and enter the 25 digit unlock code for the V2009 maps (omitting any dashes). If you currently have a GMAPPROM.UNL on the Nüvi, you can just copy/rename that.

If you go to the MAP | Info screen, with the card inserted, you should see both versions in the list of maps. Make sure that only one of them is selected at a time! Hope this helps.

Sorry it took me so long to reply. I will try this tonight. I don't think I'm making my self clear on this, I'm rather new to this so sorry for that. I would like to put the hole USA on the card so that it will fit. When I try to install from the software it only puts about 1/3 of the data and it fill up. Will this work for something like that.

Thank you very much for the info.

After installing the contiguous US on your nüvi you can use MapSource to Install Canada and Alaska on your SD card. That will only take about 100MB. There are threads here that will give you step-by-step instructions for installing the North America data on your computer for use with MapSource.