An mdm file extension is related to the Telix, a telecommunication program for DOS. An mdm file contains modem definition.
MDM file extension - Telix modem definition data
What is mdm file? How to open mdm files?
File type specification:
The mdm file extension is related to Telix, a telecommunications program originally written for DOS by Colin Sampaleanu and released in 1986.
More recent versions were distributed by deltaComm Development, including a version for Windows.
The mdm file contain modem definitions.
This mdm file type entry was marked as obsolete and no longer supported file format.
This type of file is no longer actively used and is most likely obsolete. This is typically the case for system files in old operating systems, file types from long discontinued software, or previous versions of certain file types (like documents, projects etc.) that were replaced in higher versions of their original programs.