Files with the HPI extension denote a data file used by the Graphical Environment Manager (GEM). HPI files store data and code that is used to display text on the GEM desktop. GEM uses the HPI files to display text on its primary use as the GUI for Atari systems. HPI files may be opened with compatible Atari systems.
Game archive contains game files (maps, graphics, music, sounds, textures) for Total Annihilation.
Probably old file extension or not supported application. Font information file.