Apple iMac - Using .mds - .mdf Disk Images

Since I am a novice user, I have accordingly encountered problems that I am trying to solve gradually. One of them is the inability to use disk images with the extension .mds - .mdf on a poppy. It is believed that you can simply rename mdf to iso, but somehow I am skeptical about it. Otherwise, why all this garden with two files, if everything is so simple ... For conversion, I found the MISO-J program . It picks up a .mds file (respectively .mdf) and converts everything into one iso. Then it’s a matter of technology ...

ps there is no Windows on the poppy, so I was looking for a solution specifically for the poppy