In order to convert old Adobe Pagemaker formats between different versions (for exampke .p65 and .pmd files) , you will need the program itself. Pagemaker is no longer sold, so your best hope is to find it on some abandonware websites or ask one of your friends if he doesn't have old installation disks by a chance.
Convert Adobe PageMaker 6.5 document to Adobe PageMaker document.
We have found 2 software records in our database eligible for .p65 to .pmd file format conversion.
Microsoft Windows software - convert p65 to pmd on Windows
One of the first desktop publishing programs on market
Convert from p65 file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned p65 to pmd. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
Apple macOS / Mac OS X software - convert p65 to pmd on OS X
Mac version of once popular publishing program