This is an eary attempt for a Garmin FAQ. There is a newer one that should be released soon by someone that is not me. It will replace this one sometime in the near future. -tim --------------------------------------------------------------------- Subject: Garmin FAQ Expires: 01 Aug 95 Summary: This is an attempt to answer Frequently Asked Questions about the Garmin GPS recievers that appear in the sci.geo.sattelite-nav Newsgroup. Keywords: FAQ Garmin GPS Satellite Navigation This posting is the Frequently Asked Questions (FAQ) file for the sci.geo.sattelite-nav newsgroup. Please send additions, corrections, comments and suggestions to Tim Hogard (thogard@inmind.com) CONTENTS -------- 1. Should I get a GPS40 or GPS45? 2. What is the difference between the GPS40/45 and GPS75? 3. What is 100kt speed limit? 4. How do I hook up my Garmin to my computer? 4. My GPS90/95 is out of date, how do I fix it? QUESTIONS AND ANSWERS --------------------- 1. Should I get a GPS40 or GPS45? The GPS45 and the GPS45 are internaly the same except that the GPS45 supports an external antenna while the GPS45 uses an internal one. The GPS45 uses a helical antenna while the GPS45 uses a patch antenna. The GPS45 will have better receiption in bad situations than the GPS45 but is about the same under normal conditions. Basicly it comes down to if you are going to do something where you risk damaging the external antenna, get the GPS45 otherwise get the GPS45. 2. What is the difference between the GPS45/45 and G75? The G75 is the next model up from the GPS45/45. It is in a larger case and has numeric buttons that should make it easier to enter waypoints. It also tends to go through batteries faster but seems to have the same specs on the reciever. 3. What is 100kt speed limit? All the Garmin marine units have a 99.9kt (115mph) speed limit built in. When the units get above 100kts they stop reporting their position. Since the unit will update its position once speed drops below 99.9kts it seems that this is simply a feature to sell more aviaion units. 4. How do I hook up my Garmin to my computer? The GPS45/45/90 all have a 4 pin din connector on the back. The other units use a different connector. As seen from the back of the unit: \ o data in (white) Power o o Ground (black) (red) o data out (brown) Power is 6V DC at 110ma on the GPS45. Power is 5V to 40V DC at .75W with the GPS45/GPS90. The wider supply allows you to hook it to both car/boat(12V) power supplies as well as aviaion power supplies (28V). To hook it to your computer: Garmin db25 db9 mac ------------------------------------ Ground pin 7 Data in pin 2 Data out pin 3 Depending on your computer, you may need to swap 2 and 3. 4. My GPS90/95 is out of date, how do I fix it? You can buy a new update to the aviaion database that cost about US$150. What