All floppy drives and disks look alike. That is, all 5 1/4" drives look the same as do the disks. This holds true with the 3 1/2" drives and disks as well. The big question is how do you tell a double density from a high density?

With floppy drives, it can be a problem. Most drives are not labeled as to their capacity. The quickest way is to take a high density disk and see if your drive will read it. If it does, you have a high density floppy drive. If it doesn't, you have a double density floppy drive.

Floppy disks are a little easier. In the 3 1/2" family, the extended density has a ED printed on somewhere on its case. The high density has HD printed on its case. The double density may have DD or nothing printed on its case. However, some disks are just not labeled.

Usually the 5 1/4" high density disks are labeled with HD. If not, check the box you got them from.