Could you tell me from where can I get the Digital Elevation Model data in the .DEM file extension? The option for QGIS here: https://www.qgistutorials.com/en/docs/working_with_terrain.html shows the USGS way, but there is an option for GeoTIFF only. For my purpose (terrain analysis in the Kasmir 3D software I need it in the .DEM version.
All links provided there are inactive, which is out of wonders since the data comes from 2004 year.
Could anyone share some hints?