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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 cassette tape recorder. You can save several different GPS
data files, erase 'em and record new ones, over and over again. These
GPS Data Files (file format *.usr) can be shared between, not only the
LMS-520c and LMS-525cDF, but other Lowrance GPS units and even
personal computers.
Your 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 SDC (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. (Compare that to a floppy disk's 1.44 MB capacity!) Your unit
uses all that MMC space for two key GPS purposes. (The MMC is also
used to record sonar logs.)
First, 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 unit’s memory. (NOTE:
No matter where they come from, GPS Data Files must be loaded from
the MMC into memory before your 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) not only may be shared between the LMS-520c and
525cDF, but also with other Lowrance GPS and sonar/GPS units as
well as personal computers. (For example, the exact same MMC, cus-
tom map files and GPS data files can be used interchangeably between
your gimbal-mounted unit and the hand-held iFINDER™ GPS re-
ceiver.)
Your unit automatically reads Custom Map Files directly from the
MMC or SDC. 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,