- Nov 18, 2005
About the Data
Generally speaking, four kinds of information can pass between a GPS and a computer:
- Waypoints are individual locations, normally indicated by latitude and longitude. These can be points already programmed in the GPS, such as cities or point of interest; or points that you add, which are called user waypoints.
- Tracks or track logs are collections of points that, when joined together with a line, make up a path. Tracks can be created automatically by the GPS as you move from place to place with the GPS turned on.
- Routes are collections of waypoints for going from one place to another via specific locations. Routes are normally programmed into the GPS to indicate how you want to get from one place to another.
- Maps consist of specially formatted data to display map information such as roads, topographic lines, and cities on a GPS.
Although basic maps are built into GPS models with moving map features, some GPSes also support the upload of supplemental map data from a computer to the GPS. For example, I use my GPSes for off-road travel and exploration, so I upload topographical maps to the GPS for the areas I want to explore. So, while I'm in those areas, I can see topographic lines (for elevation), unpaved roads and trails, water sources, and other data that normally wouldn't appear in the GPS.
The transfer of map data between GPS and computer is usually one way: from the computer to the GPS. New map data uploaded to the GPS overwrites whatever was uploaded last time. Since the GPS doesn't have any map data that the computer doesn't have, there's no need to transfer map data from the GPS to the computer.
The transfer of map data is where things are tough for Mac users: There's no Macintosh GPS map software that supports the upload of map data from a Macintosh to a GPS. So, for example, to get that map data onto my GPS, I have to fire up my PC, pop in a Garmin disc, and use the Garmin software to upload the maps I want. (Of course, if you have Virtual PC for Mac and can run Windows on your Mac, you're all set. And you won't need this article, either.)
But Mac users can transfer waypoints, tracks, and routes between a GPS and a Macintosh. That's what this article covers.