Mac Marginalization: GPS

Mac Marginalization: GPS
Dan Simpson
I am one of the Odd Balls that uses a Lowrance iFinder GPS and a Mac. Until now I have been unable to use my GPS Data files with my Mac. Lowrance uses a proprietary file format that no Mac GPS software can read…until now.

I recently discovered an app called Load My Tracks from ClueTrust. It converts Lowrance .USR files into .GPX and .KML formats.

I am not affiliated with Lowrance or ClueTrust. I am just happy to have my stuff working together and I want to pass it along to other Mac/iFinder users. I can’t be the only one…can I?

GpsPasSion Forums – Map Update Using a Mac

GpsPasSion Forums – Map Update Using a Mac
1. obtain the v8 udpate DVD (this is not the risky part [g]). Go to and follow the links to set up a MyGarmin account and obtain an unlock code. Copy that code to your desktop in a Sticky or text file. Be sure it contains no spaces or dashes.

2. connect your nuvi to your Mac USB port (neither is this risky, as long as you un-mount it properly – see step 6).

3. MANDATORY! Do a complete backup of every file on your nuvi. This is your best hope for avoiding trouble or recovering from it – I have in fact successfully reformatted my nuvi, erasing everything, and re-installed v7 with no problem – all on a Mac. Note that v7 came on my unit and therefore I did not have to do any unlocking stuff.

4. copy the gmapprom.img file to the Garmin folder on your nuvi from the DVD. It is located in the Rgn folder on the disk. This should take a long time – as much as an hour to transfer the 943.1 MB in v8. This will erase v7. No turning back now. Be sure your Mac is set not to sleep or spin down its hard drive.

5. create a file called gmapprom.unl in a plain text editor. Put the unlock code, in the proper format, into this file (no dashes or spaces) and save it to your nuvi’s Garmin folder. The code is 25 characters, in something like this format (this is my old V7 code, randomly changed to prevent mischief): 5XXXXX9E1ZSSF7U88G6Q2ZZVL. Make sure your Mac is not adding an extension other than .unl.

6. be sure to empty the trash first and then eject your nuvi as you would any external drive device. OS X 10.4.x will not allow a proper dismount this way, however. So launch Disk Utility and select the nuvi, then click Un-Mount (not Eject). It is then safe to unplug the USB cable.

Nuvi should reboot and if you press Settings, then Map Info you should see v8 in the menu.

If v8 does not appear, power off and restart your nuvi then re-mount it and look for the 943.1 MB gmapprom.img file and verify the contents of your unlock code file (gmapprom.unl). Check for typos in the code or a stray CR or LF in the file. Be sure no other codes are in it.

If things go horribly wrong, don’t panic. You can get back to v7 if you are careful. If, for example, you end up with garbled filenames in the nuvi directory and severely impaired nuvi functions, use Disk Utility to format the nuvi “drive” as an MS-DOS file system drive.

Then drag all the backup files you created in step 3 (see why this is a vital step?) back onto your nuvi. It will take up to an hour, but at the end you should have a working nuvi with v7.

GpsPasSion Forums – Firmware updates with Macintosh

GpsPasSion Forums – Firmware updates with Macintosh
This info has become scattered or dropped off the board, so here is a quick tutorial on how to upgrade nuvis using a Macintosh OS X computer. (The same general technique works on Windows machines.)

Here’s how I did a firmware update on my nuvi, using a G4 iMac running OS 10.3.9. Standard disclaimer: I cannot take any responsibility for the results.

Download the updater from Garmin. It’s a Windows executable (exe) self-extracting archive, but fear not. Launch Stuffit Expander and drag the exe file onto its icon. Stuffit handles it just fine – as long as you use Stuffit v10 or earlier. Stuffit v11 does not work. Ignore the extracted Windows-only programs with names like Copy2Card.exe.

Using the supplied USB cable, mount the nuvi on your desktop. If you are updating from firmware version 2.9 or earlier, be sure to make a backup copy of the waypoints.gpx file (or current.gpx under newer FW versions) in the nuvi’s Garmin folder.

As with all nuvi procedures, be sure you have a FULL backup of your nuvi before changing anything.

Use a removable SD card, not your nuvi’s internal storage, for the update procedure.

Using an SD card, either in a card reader (faster, if you have USB 2.0), or using the nuvi to access your SD card (slower), drag the Garmin folder from the extracted archive to the SD card. Be certain that you are NOT replacing the Garmin folder in your nuvi’s main directory (you will lose your maps). Unmount the nuvi and the SD card the same way you would eject any USB device from your desktop. If nuvi automatically re-mounts, use Disk Utility to un-mount it.

Turn the nuvi off and to be safe, plug it into its AC adapter. With the SD card in the nuvi’s slot, turn the nuvi back on. Be patient and do not interrupt it while it goes through the entire update process. Then copy your waypoints file (which includes “Favorites”) back into the nuvi, if necessary.

Note that the only requirement for the SD card to accomplish the update is that it have the Garmin folder on it. Existing files such as MP3s or photos do not need to be removed, as long as there’s room for the updater folder. Once the firmware is updated, you do not need the card or the updater for the GPS to work properly.

To be sure you get such extras as voices and GPS SW updates at the same time, try this method supplied by FreeBird using v3.30 as the example:

(make a backup of the changed/deleted files first).

1.) Extract from downloaded Offline Updater V3.30 the two .bin files (006B047800.bin is the GPS SW and 006B048201.bin is the TMCxx SW).
2.) Copy the two files into the Garmin directory on the Nüvi (overwriting or saving the existing files).
3.) Delete the file GarminDevice.xml in the Garmin directory on the Nüvi.
4.) Restart the Nüvi in normal mode (not connected to the PC).


5. for those considering route 66 with GPS
Posted by: “alice magooey” alicemagooey
Date: Tue Jan 9, 2007 1:42 pm ((PST))

i received this letter e mail from route 66 support

Thank you for your interest in ROUTE 66 products.

ROUTE 66 Route 2004 is the latest available version.

In order to use the GPS option in the ROUTE 66 program, the GPS device must
meet the following requirements:
– The protocol used by the GPS device must be fully NMEA-0183 2.0
(or higher) compatible.
– The minimum protocol requirements are that the RMC sentences have
to be sent.
– The MAPDATUM used in the ROUTE 66 program is WGS-84.

If you are using a Keyspan USB Serial Adapter (USA-19), you have to download
the Keyspan USB Serial Adapter Software for Mac OS X version 1.4 and install
it on your computer (

If you are using a USB or PCMCIA GPS receiver, please install the driver
supplied by the GPS manufacturer.

The Bluetooth GPS receivers that meet the above mentioned requirements are
compatible with the ROUTE 66 software and do not require additional software
to work.

Please note that the following GPS receivers are not compatible with “ROUTE
66 Route 2004”:
– DeLORME Eartmate USB
– Garmin USB
– Navman USB

Information regarding GPS systems can be found at:
– Royaltek [ ]
– Leadtek [ ]
– Holux [ ]
– Haicom [ ]
– Pharosgps [ ]
– Emtac [ ]
– Globalsat [ ]
– Mehaffey [ ] (biggest GPS info site we
– GPS24 [ ] (info)

Best regards,
route 66 customer service

Calculating Area

Subject: Re: surveying

1) If you have a GPS device which calculates area after you walk the fields
verify that with other methods. Do not just trust the device but compare it
to your own calculations.

2) Get out your geometry book and plat maps for the sites in question.
Divide the non-recalinear fields into standard geometric shapes and calculate the
area of each then add them. Estimate a regular shape out of the irregular
shape cutting off equal area both inside and outside the estimated shape.

3) Look at the county plat maps as they usually have the area of a lot
calculated in the center below the circled last digits of the Assessors Parcel
Number (APN). If say, 3 fields you are calculating are within a single lot make
sure the added total of the fields do not exceed the area of the lot.

Look at your estimate for reasonableness to make sure you haven’t made a
decimal error. If you have arial photos, compare the fields to similar sized
lots with known areas that are in the same scale.

If you publish your estimates for any reason include a disclaimer the rough
estimate is only for that specific purpose and is not guaranteed to be accurate
but believed to be reliable. If accuracy is required, hire a surveyor.

Useful info:
One Acre = 43,560 Square feet
One Hectare = 107,639
One Square Kilometer = 100 Hectares
One Square Mile = 640 Acres = 2.59 Square Kilometers

Area of a circle is 3.1416 x radius2 (A=Pi x r2)
An oval or egg shape has less area than a circle with the same circumference.
Area of a triangle is roughly half of a rectangle made from the triangle base
up to the height of the triangle.