MICRODEM is a microcomputer mapping program.

MICRODEM displays and merges:

digital elevation models
satellite imagery 
scanned maps
vector map data
GIS databases

This program manipulates digital map data.  All data used must be registered, meaning that it has earth coordinates associated with the data.  While the program has some capabilities to create and register data sets, this requires a high degree of user sophistication and is not recommended for most users, and is not a major focus of program development.