Deleting Maps From Internal Memory - Magellan RoadMate 300 Reference Manual

Maps

Deleting Maps from Internal Memory

You can delete a map from internal memory only if the current map you are trying to upload requires more space than is
available.
Select the regions you wish to upload. The application will calculate the
size of the regions and the available space. Select Save.
Give your map a name and select OK.
A dialog box will appear, telling you there is not enough space available,
along with a list of maps currently in the unit's memory. Select which
map or maps you wish to delete and select Delete.
After the maps have been deleted, the application will start uploading
your new maps to the unit's internal memory.
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