Garmin PC150 Owner's Manual page 51

The bar graph on the bottom of the screen displays satellite availability at the
selected position. The horizontal time scale is in one hour increments and
the vertical scale shows the number of satellites visible.
The "OK" button in the top right corner of the screen or enter-key is used to
exit the satellite visibility screen. A similar button below the "OK" button or
a Cntl-P can be used to print the screen.
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