Dlgvu displays USGS digital map data. Path files are text files of coordinates such as those uploaded from GPS receivers. Lines ending with two decimal values are interpreted as specifying latitude and longitude in that order. Lines without data indicate breaks between paths.
All interaction is via mouse actions and keyboard shortcuts.
The display window may be resized as desired. A ZIP archive can replace a directory name if Icon can open the unzip program via a pipe. To zoom to a particular region, sweep out the region using the left mouse button. To cancel a sweep, reduce its width or height to fewer than ten pixels. If nothing appears to be happening after zooming in, the program is probably drawing offscreen.