can data be retrieved from a floppy disc when plastic case is broken?

Answer 1

Depends how bad the case is broken. If it's still able to be inserted and the data disc is still good, then yes, as long as the data disc itself isn't scratched or otherwise damaged.

Answer 2

Get another floppy and very carefully open it up.Try not to touch open disc( handle by center hole ) Open damaged disc and swap covers, putting your copy into good cover. Squeeze cover back together and you should be set to go. Don't do it near anything magnetic.