Toilet Duck if you haven't found it yet here it is...
http://www.garmin.com/manuals/GNS430_PilotsGuide.pdf

it's on page 7-17

If that link didn't work you can download it from the garmin site here...
http://www.garmin.com/products/manua...t=010-00139-11

download the " Pilot's Guide, Rev. J, Jun, 2006"