Using the "Export to shapefile" feature in ArcCatalog and performing tools like "Append" and "Merge" from ArcToolBox provided a way for you to merge small amount of DGN or Coverage files. However, some users may find difficulties in merging vast amount of such files since the iteration function in geoprocessing tools is only available in ArcGIS 9.2 version, the purpose of this script is to help users to overcome this difficulty when using ArcGIS 9.1 to deal with merging of large amount DGN or coverage files.

This script is able to merge either DGN or Coverage files which are placed in the same folder. Files in sub-folder can also be merged. The supported feature types for this script are Point, Polyline, Polygon and Annotation. The output location, name, fields structure and spatial reference can be defined by the user.