Here is a more detailed description of the map conversion process with actual times and file names shown.

Windows on the PeeCee

UnlockWizard

Before you begin converting any maps, you must insure that they are unlocked for the GPS receiver that you will be installing them on. This is not normally a problem because most maps will already be in use and unlocked. Note that not all maps are lockable; my version of TOPO US 2008 has no locks.

You must unlock maps on Windows because there is no equivalent Mac program to do so.

Maps registered with MapSource

These are maps that you have previously installed and used MapSource to open. They are shown in the maps pulldown list in MapSource.

Maps are "registered" in the Windows registry, a behind-the-scenes internal Windows process that occurs automatically when you first open each map in MapSource.

MapConverter application

Download MapConverter from Garmin's website and install it according to the instructions.

Start MapConverter. It will look for registered maps and shows a list.
Select the maps you want to convert. Click "Next >".
 (You don't have to do all the maps at once; one at a time is ok.)
Select the destination for the converted maps. Click "Next >" and wait.
You'll see something like this [my time notes are here]:

Converting...
Colo 24K Topos. (1 of 2)  [takes about 1 min]

Compressing
Colo 24K Topos. (1 of 2)  [takes about 1 min]

Converting...
TOPO US 2008. (2 of 2)  [takes about 13 minutes]

Compressing
TOPO US 2008. (2 of 2)  [takes about 15 minutes]

The conversion of Garmin map products for use on the Mac is complete.

mapname.tgz files on hard drive

MapConverter makes one tgz file for each map that it converts; mapname is the map name. A tgz file is a compressed converted version of a map ready for transfer to the Mac.

tgz file sizes:
Colo 24K Topos  289,281 KB  (about 282 MB)
TOPO US 2008   2,785,558 KB  (about 2.66 GB)

Thumb drive

You can move tgz files to the Mac several ways:
* Copy the files to a thumb drive (aka, jump drive)
* Burn the files onto a DVD
* Transfer the files over an ethernet connection
* Transfer the files via Mac "target mode"

MacOSX

Thumb drive

Drag copy the tgz files from the thumb drive (or other) to the hard drive.

mapname.tgz files on hard drive

tgz file sizes:
Colo 24K Topos  289,281 KB  (about 282 MB)
TOPO US 2008   2,785,558 KB  (about 2.66 GB)

Unarchive

Double-click each tgz file to expand the file into a gmapi file.

mapname.gmapi files on hard drive

gmapi file sizes:
Colo 24K Topos  316,298 KB  (about 303.6 MB)
TOPO US 2008   3,232,006 KB  (about 3.06 GB)

MapManager

Download MapManager, MapInstall, and Bobcat from Garmin's website and install them according to the instructions.

For each gmapi file, double-click the file to start MapManager. Click the "Install" option to install the map.

MapManager converts gmapi files into gmap files and installs the gmap files (in a library) making them available for use in any Garmin Mac application that uses maps.

mapname.gmap files

gmap file sizes:
Colo 24K Topos  316,292 KB  (about 303.6 MB)
TOPO US 2008   3,232,000 KB  (about 3.06 GB)

The gmap files are stored in
  ~Library/Application Support/Garmin/Maps

You may discard (trash) the tgz and gmapi files; they are no longer needed.

MapInstall     Bobcat

Run MapInstall to install maps on your GPS receiver.

Run Bobcat to create waypoints, tracks, and routes on your Mac and to move waypoints, tracks, and routes between your Mac and GPS receiver.

GPSrcvr        GPSrcvr