The executable programs (INTG.EXE and XNTG.EXE) were compiled for use on an IBM-compatible PC using the respective source code (INTG.FOR and XNTG.FOR). The INTG.EXE program will interpolate geoid heights from data files using user-provided coordinates. The XNTG.EXE program will extract sub-grids from the binary data files, as well as convert back and forth between binary and ASCII, or just give statistics about a data file. To use G99BM, the INTG.EXE executable and at least one data file must be downloaded. You need only to select those data files that cover your region, and the INTG.EXE program will recognize which files are present. If you are running G99BM on a 386 machine, you will also need to download the DOS extender file.
Currently, these data files are presented in a non-graphical interface only (i.e., user must determine the desired data files based upon the extents of the data files and the region of interest). The interactive graphical interface is under construction and will be completed at a later date.