I didn't know this but found out, to my cost, when I
entrusted a MED module to a HD disk formatted as DD. It corrupted as did the backup copy on another disk and I lost a module I'd been working on for a long time. It also probably had something to do with the dying Chinon drive in the 500 I had.
I always thought that DD disks were just HD disks that had failed a few read/write tests and so were
inferior quality - so how come HD disks more prone to errors when formatted as DD?
