Michael Cook

The main point of RouteBuddy seems to be the detailed road maps that you can use on the Mac. You can see your track on the map, or follow your position in real time. Note that these maps are only for use on the Mac: they can't be uploaded to the GPSr. There are no special features for geocaching: you can use it to transfer the waypoints, but other programs (including free ones) will do that as well. RouteBuddy communicates with the 60csx over USB: no problem. I'm not buying it for the moment: for me there are not (yet) enough features to make it worth the price, but I shall continue looking at it. And my 60csx has certainly not suffered from being hooked up to the Mac.

I have this map on my 60csx. It works OK, apart from a display problem which makes certain coastlines disappear when you zoom in:

If you buy low-end with no possibility to add maps (Magellan 300, for instance) the only map you will have is the basemap, so you really have to choose between european and american. If you buy high-end with removable memory cards (Garmin GPSMap 60cx or Magellan 600, for instance) it's not important: I'm perfectly happy with a US Garmin 60csx in Europe. The basemaps in these models are not much use anyway, and although you can't replace them you have enough memory to add all the maps you need.

Try here: http://www.gpstravelmaps.com/ or here: http://mapcenter.cgpsmapper.com/catalogue.php or here for a whole selection of links: http://forum.ttqv.com/viewtopic.php?t=7619

What the barometric altimeter measures very accurately, particularly over a short time span, is the change in altitude. But you must tell it at what altitude it starts, since it doesn't have a way of measuring the actual altitude from sea level. If someone dumps you somewhere with just a barometer, there is no way of deducing your altitude from the barometer reading alone. In this situation, if you now walk up a hill, what the barometer can tell you is how much higher you now are in relation to your point of depart. GPS does measure the actual altitude, but the value it gives can change dramatically in just a few minutes, even if you are in fact standing still, depending on satellite positions and quality of reception. So we have two very different ways of determining altitude: a barometer, which needs to be calibrated and will then be accurate over a short period of time, but as the hours pass will "drift" because of changes in the weather, and GPS, which is most of the time less accurate than the barometer but is not affected by the weather. Let's say you calibrate your barometric altimeter to a known value (the altitude is indicated on the map), then run up a hill in a few minutes. Counting on the fact that the barometric pressure at sea level rarely changes much in just a few minutes, the altimeter should give you a very accurate estimation of your present altitude, whereas the value calculated by the GPS may be way off. If you now go on walking for several hours, things can look different: maybe the barometric pressure at sea level has changed by a significant amount, affecting the altimeter reading, and maybe the GPS has had the good fortune to have several moments where it had an accurate elevation reading. Obviously both methods have their strengths and weaknesses, and if Garmin has got things right, they should be able, by combining the informations given by the two different systems, to produce more accurate and consistent results than with one system alone. I guess what the auto-calibration feature in the Garmin 60CSx does (or at least tries to do) is to look at the quality of the signals and the geometry of the satellites and then only to use the GPS-determined value to re-calibrate the barometer when it has calculated that the GPS reading is accurate enough. Maybe it looks at the moments where the GPS reading is the most accurate and makes an average. For some more information on all this, download this Garmin brochure: Using a Garmin GPS with Paper Maps and look at pages 38 and 39.

Automatic calibration is a bit of a strange thing, since the the GPS readings used for the calibration are usually less accurate than the barometer readings! I guess this means that in auto-calibration mode the instrument does a lot of averaging over time to minimize the effects of GPS errors, and only re-sets the barometer when there has been a significant difference between barometer calculated altitude and GPS elevation more than a certain time. If the auto-calibration sets the barometer too often, you will lose the benefits of the accuracy of the barometric altimeter. The point is this: the barometer has no way of knowing your actual altitude, but it can measure very accurately a change in altitude. So the best thing is only to use auto-calibration if you have no better information. If you happen to know your correct altitude (because it's marked on the map, for instance), calibrate the altimeter to this altitude. I just re-calibrate the altimeter when I get the chance: it's usually not far from the truth and the re-calibration only takes a few seconds once you've got used to it. To help you in your decision, maybe we need to know more about why accurate altitude information is important for you. And don't forget the other difference: the compass. Some people love it, others couldn't care less.

That doesn't seem right to me either. I only have one GPSr (Garmin 60CSx), but if I check it against a radio-controlled clock it shows exactly the same time.

GPS does not determine altitude as accurately as it determines the horizontal co-ordinates. A barometric altimeter can give you better accuracy, provided you understand its limitations. The important thing to consider with a barometric altimeter is that it only measures the pressure of the air around it ("ambient pressure"). When this pressure changes, the change could be a result of a change in the weather ("barometric pressure" or pressure measured at sea level), a change in altitude, or a combination of both. It's up to you to decide. If the barometer is fixed to the wall of the room, you can safely assume that any change that it measures in the air pressure is due to a change in the weather. If you have a barometer with you on a one hour balloon flight, you may reasonably assume that changes in the measured air pressure during this hour are mostly due to changes in altitude. We have to count on the fact that the barometric pressure doesn't usually change very rapidly. In the case of the GPSr, if you go on a hike or a ride that lasts a few hours, it is reasonable to assume that the changes in measured air pressure are largely due to changes in altitude. Whenever you are at a known altitude, or can find out the barometric pressure at sea level, you should use the opportunity to re-calibrate the altimeter. For instance, if you start out from somewhere where there is a fixed barometer, you calibrate the altimeter to the value given by this barometer. If, when you reach point "x", you have the possibility of phoning somebody who can give you the present reading of the fixed barometer, you can re-calibrate the altimeter and calculate the difference in altitude between where you started and point "x" to an accuracy of a few feet. A little personal test: I left my 60CSx near the window of my home (where the GPS reception is admittedly pretty bad) for a few hours. Within this time I noticed GPS elevation readings as different as 72 meters and 123 meters. During the same time the barometric altimeter registered values between 102 meters and 109 meters.

Day and night settings. Go to Setup > Display to change these as you wish.

Garmins do have USB ports. My 60csx is at present connected to my Mac via USB. I can download geocaching waypoints directly from the Internet with Geocaching Menu. I can transfer tracks or routes to and from the 60csx with LoadMyTracks. I'm trying out RouteBuddy which is a promising new mapping program for Mac. And if I turn on USB mass storage mode on the Garmin, it appears on the Mac desktop like any removable drive. All this works straight away: no drivers to install, no hassle. For firmware updates and transferring maps via Mapsoure I still need VirtualPC and Windows, but Garmin have announced that they will be bringing out Mac versions of their software towards the end of the year: let's hope we don't have to wait too long.

It isn't possible to put a .jpg in the Magellan. JPGs are bitmap format images, but the Magellan maps have to be vector format. If you have a laptop with you on the boat you could use something like OziExplorer or GPS Trackmaker. With these programs you should be able to use a scanned map as a backgound. With the Magellan connected to the laptop, you will be able to see your position on the detailed map on the laptop screen.

If you need the compass, it's the Explorist 600 you want, not the 500.

Do you need the barometric altimeter and electronic compass? Then the comparison should be between the 60CSx and the Explorist 600. If you don't need these features, the choice would be between the 60Cx and the Explorist 500. All these models have very good satellite reception (An interesting comparative test regarding reception can be found here: http://www.mtgc.org/robertlipe/showdown/). If the type of battery should be a deciding factor, check out this thread. Regarding ease of use, size, weight, feel of buttons, etc. the best thing to do is to find both models in a shop and try them out. Otherwise, if the "geek factor" is important, the Garmins have more menus/options/stuff to play around with than the Magellans. If you happen to have a Mac, note that Garmin has announced support for Mac OS for the end of this year, and that there are already some Mac apps (LoadMyTracks or RouteBuddy, for instance), which will communicate with the Garmin 60CSx over USB. Have fun choosing and don't rush the decision!

I guess that MapSource won't start if there is no Garmin folder in HKEY_LOCAL_MACHINE. You'll need to create this registry entry: perhaps you can copy it from the other installation and edit the paths as necessary? If it's any help, here's what the registry entry for Garmin looks like on my computer (Mac running Windows 98 on VirtualPC):

I am supposedly on the mailing list that announces updates, but I haven't received any notification. Did anybody who signed up for email alerts get notified of this update?

Use regedit to open the registry. Navigate to HKEY_LOCAL_MACHINE > Software > Garmin > MapSource > Products. Each key number under Products corresponds to a map. Delete all these keys: Mapsource should now open, but with no maps. You can then use a program such as GPS Map Manager or MapDekode to re-install the maps into MapSource.

On my 60CSx I see Americas Marine Point Basemap, , Jan 2001 (exactly like that, with two consecutive commas). This is selectable. I note that the basemap seems to be there, regardless of whether I select the "Marine Point Basemap" or not. At the coordinates you specified, there is no lake. The nearest town on the map is a place called Lakeshore, which does sound hopeful, but there is no sign of any water on the map. There's no road either, in fact.

I bought a copy of Virtual PC 3.0 + Windows 98 for a few Euros on ebay. It runs fine on my old iBook (for this version of Virtual PC you need a Mac that boots in OS 9.2) and the USB connection with the 60 CSx also works: I have already uploaded a map with MapSource and updated the unit software with WebUpdater.

There's a litle bit more info here: http://garmin.blogs.com/my_weblog/applemac/index.html

In my apartment, in a house built with reinforced concrete, I don't get any reception at all with the 60 CSx. In one room I can get a weak reception by getting right near the window, but the windows of the other room have some sort of metal coating (from the outside they look like mirrors), and the only way I can get reception there is to open the window and hold the 60 CSx outside. Apart from that, I get reception in trains, cars, brick houses, under bridges, in backpacks...

Many thanks. How did you find that url? I can't find a path to it from the "Updates and Downloads" page.

I don't think that is how it should work. I am not telling the unit that I am not moving. I am telling it that it is not moving. In particular, I am telling it that it is staying at a certain height (104 meters). A barometric altimeter only measures one thing: the pressure of the air ("ambient pressure"). When there is a change in the air pressure, the sensor has no way of telling if this pressure change is due to a change in elevation or a change in the weather (i.e a change in the barometric pressure, being the air pressure at sea level). You, the human user, must decide whether to interpret the change as a change in elevation or a change in the weather. For the first option you make the assumption that the barometric ("weather") pressure does not change, for the second option you make the assumption that the elevation does not change. In this case you use a known value for the elevation and use the standard barometric formula to calculate the barometric pressure. When I select "fixed elevation" for the altimeter, I am telling the unit to use the elevation value I entered to calculate the pressure. This only makes sense if the value for the elevation remains constant.

Precisely: why does the Garmin concern itself with elevation if it's only meausuring the barometric pressure? Since GPS is turned off and I've told the unit to fix the elevation at 104 meters, that is where it should stay. Of course I could just ignore the changing altitude reading, but it does make me suspicious that something is not functioning correctly.

Yes, certainly that is true if "Variable Elevation" is chosen in the setup. But the point of the "Fixed Elevation" setting is to keep the elevation reading constant, so that the barometer will function like a standard fixed barometer, showing the ambient pressure. Why have a "Fixed Elevation" setting if it doen't in fact fix the elevation?

I am having a great time trying out all the features of my new 60CSx. Here's something I don't understand: I choose Barometer Mode: Fixed Elevation in the altimeter setup, but I still see the elevation changing. Here are the details of the setup: - GPS is Off. - Altimeter Auto Calibration is Off. - Altimeter is set to Fixed Elevation. - I calibrated the altimeter to my known elevation (104 meters). With these settings I would expect the elevation reading not to change. It can't be affected by GPS data since GPS is turned off. And I turned off auto calibration, so the altimeter shouldn't be surreptitiously re-calibrating itself. I thought the whole point of the setting "Fixed Elevation" is that only the barometer reading should change, but I see that the Elevation reading changes as well. Since this morning the Elevation reading has crept up from 104 meters to 114 meters. Can anybody explain why this happens? Best wishes, Michael