Hi
> MS-DOS either says that "the disk is unusable, either the thing is defect or the track 0 is damaged"
I have bad experiences in formating HD disks as DD disks, the density of the read/write head seems to have problems with this, therefore it doesn't work with all HD disks (as one might expect if formating in a lower density). In fact I have major problems in formating any floppy-disk on any PC. I think the disks that are sold now are already very old, because noone uses them any more...
> or it starts "formatting" but it would take 20 minutes or so to format
The damn MS-D**F tries to save the contents of any disk that is formated to allow the "unformating" of a disk (see the dos command "Unformat"). If the disk hasn't been formated or has been previously formated in a different format (as in this case) the stupid OS needs very long to detect that there is nothing it could save for unformating :-(
You should call the format command with the following arguments to suppress this behaviour:
Format A: /U
(the argument /F:720 should not be required if the HD-hole is covered by a sticker)
Noster