Guys:
You are confusing apples and oranges here.
"MapSource" is the name of the PC computer application that is used to both view Garmin cartographic products on a computer screen, and to upload segments of these cartographic products to a Garmin GPSR.
MapSource, by itself, has no mapping data.
You will get a copy of MapSource from Garmin free of charge when you buy any cartographic product. You also get a copy of MapSource, and a cartographic product, included with the purchase of just about every GPSR they sell, the only exceptions being the $100 handheld units intended for children's use.
If you want to see African cartographic data, you need to get a copy of the Garmin product called "WorldMap". This product, though rather old, is still sold by Garmin. It contains a fair amount of data - about the same level of detail as a Michelin map - for Africa. The data dates from about 1998 or so.
You then view the WorldMap data using the application called MapSource, and if you wish, download segments of it to your GPSR.
Once you have one copy of MapSource, you can obtain free upgrades to future releases of the MapSource program (note carefully: the PROGRAM, not updated map data) from the Garmin website. The URL for the free updates is:
http://www.garmin.com/support/download.jsp
Regards,
PanEuropean