JeepCheck

The PN-20 uses the STM chipset which is really great. There was another post earlier about Garmin switching to it in the future, as it is more consistent than the SiRF 3. It's really great in that when you get a signal it takes an awful lot to loose it. I currently use mine a whole lot for road routing, and often make short stops. I slip it under the seat of my car while I go inside, and it still has a lock on me when I get back and pull it out, that's pretty amazing. http://www.gpsreview.net/stmicroelectroncs-teseo-gps-chip/

The reason is because the PN-20 is waterproof and has a unique hookup system using 8 contacts built into the case on the back of the unit, that the connector slides over. Standard USB into the unit would require some kind of cover over the hole that would require being waterproof. Note that the cable has a standard USB connector on the other end.

Unfortunately no. 3D is generated on the fly as you move the 2D maps, by the program, processor and video card on the desktop. The PN-20 doesn't have that kind of processing power and the screen is too small to really enjoy the effect of if.

I just wanted to point out that you have complete control over what data is displayed at what zoom levels, by using the Data Layering menu option on the Map Page. You also control the zoom levels the maps are cut at, so if you find the defaults don't work, you can adjust them. Currently, I have been using the PN-20 a lot for road navigation. I make Street Atlas type maps by removing all topo type data from very large areas of the state. I don't need shaded relief, contours or land cover when doing road navigation. For ATV you will want some of these, but my point is you can cut them for what you need. You can setup the maps in your mapset (3DTQ, Aerial, Satellite, and Topo) to display the type of data you want to see at different zoom levels. Even after you do that, you can still change what is displayed at a given zoom level, by turning off either a specific data type, or the map that is displayed. This of course all depends on the data you are using, and what zoom levels the data is displayed appropriately at. It's easy to over/under-zoom ADP data, but with Topo and the PN-20, that's totally controllable by the customer. If you don't like the looks of aerial or satellite at a certain zoom level, just change the level the maps are cut at. To the best of my knowledge, there is no other GPSr or PDA that will give you this much control over what is displayed, when you want it.