making software, MapCreate 6 or one of our special plug-and-play mapping cards. Some unit features — such as searching for businesses and addresses — won't work without a custom MapCreate map. There is so much detail in our background map (and even more in MapCreate) that we'll describe their contents and differences in Section 3, Basic GPS Operations, on page 93.

Another portion of the unit’s onboard memory is devoted to recording GPS navigation information, which includes waypoints, event marker icons, trails and routes. This lets you look back the way you came. Think of this data storage like the hard drive memory in a computer or a tape in a cas- sette tape recorder. You can save several different GPS data files, erase 'em and record new ones, over and over again. Like any computer file, these GPS Data Files (file format *.usr) can be shared between Eagle GPS or sonar/GPS units or even personal computers.

This unit has one more thing in common with a personal computer. Just as computers have a floppy disk drive for storing and exchanging files, the unit has a slot for an MMC (MultiMedia Card) or SD card (Secure Digital card) flash memory card. These solid-state memory devices are about the size of a postage stamp, but can hold data ranging from 8 MB to 1 GB in size. (Compare that to a floppy disk's 1.44 MB capacity!) This unit uses all that MMC space for two key GPS purposes.

You can backup your onboard GPS Data Files by copying them to the MMC. Since the MMC is removable (like a floppy disk or a cassette tape), you can store these GPS Data Files on a personal computer equipped with an MMC card reader. (Or store them on a pocketful of MMCs, if you don't have a computer.) Our MapCreate mapping software can save, edit or create its own GPS Data Files, which can be copied to the MMC and then loaded from the MMC into the unit's memory. (NOTE: No matter where they come from, GPS Data Files must be loaded from the MMC into mem- ory before the unit can use them.)

The other key GPS use for MMCs is storage of special high-detail, cus- tom maps, which you can produce on your computer with our MapCre- ate software. These MapCreate custom maps contain much greater de- tail than the basic background map. These Custom Map Files (file format *.lcm) can also be shared between Eagle GPS or sonar/GPS units and personal computers. This unit automatically reads Custom Map Files directly from the MMC or SD card. To use a custom map, all you need to do is slide an MMC containing a map into the unit.

Introduction to GPS and WAAS

Well, now you know the basics of how your unit does its work. You might be ready to jump ahead to Section 2, Installation & Accessories, 7

Page 15
Image 15
Eagle Electronics 502cDF manual Introduction to GPS and Waas