If you are unsure which type of file you have, check the file size and origin:
If you are running PageMaker 7.0, use a virtual printer driver (like CutePDF or Adobe PDF Printer) to "Print" the document directly into a portable PDF file. Converting MMD PMD Files to FBX or OBJ pmd file opener link
PMD files are highly susceptible to corruption if they were saved on old floppy disks or CDs. If InDesign crashes while opening the file, the data may be permanently unrecoverable. To help find the right tool for your project, let me know: If you are unsure which type of file
In modern contexts, .pmd files are often 3D polygon models used in MikuMikuDance (MMD), a popular Japanese freeware animation program. How to Open Adobe PageMaker PMD Files let me know: In modern contexts
