Take a look at the
Malsingmaps web site. They have very much information about maps and GPS in Malaysia and Singapore. If you are interested in using maps that are compatible with Garmin GPS devices and can find maps you will use at Malsingmaps or other places, you can read about how to use them in the Garmin Mobile PC section of this forum.
Here is a discussion that can help. You need the Garmin Mapsource program to view maps on your PC.
http://www.laptopgpsworld.com/914-how-install-mapsource-add-maps-mobile-pc#post5874
The first message in the discussion describes how to install Mapsource if you do not own any Garmin maps. When you have Mapsource installed on your PC and some Malaysia maps installed in Mapsource, then you can download the "nroute" program from Garmin's web site and use it for navigation. Or you can buy Garmin's Mobile PC program for navigation and load the maps into it from Mapsource.
If you read more of the discussions in the Garmin Mobile PC section you will see lots more information about the Mobile PC program and also the "nroute" program.
...ken...