On 10/11/09 17:42, ael wrote: > I tried setting the density to dd instead of hd -- something that I > had also tried on fdformat without success. gfloppy managed to
This is indeed very useful information, sorry to have not spotted this earlier. Double density disks cannot be formatted as high density. Not only because of the higher surface quality of HD disks, but more importantly because the presence or not of the density select hole switches the _drive_ into the appropriate mode. Software switches the FDC (which is on the motherboard) into the correct mode, whereas the hole switches the drive itself into the correct mode. Unfortunately, there is no communication about density between drive and If both disagree, formatting will fail. For most DD disks, surface quality should be good enough for HD (at least when new...), but (normally...) you do need to drill that extra hole. Computer magazines from the period of DD disks were full of articles suggesting to do this... :-) Now, if your disk _does_ have a HD hole (do not confuse this with the write-protect hole), maybe the LED sensing this hole in your drive is broken, and it wrongly considers every disk as DD? > verify to around track 73. This now is probably due to poor quality of disk (maybe due to age?). It's mostly the higher tracks that fail, because on them the spatial density is highest (these are the innermost tracks, thus shorter, but they still contain the same amount of data => more bits crammed into less surface). > I tried installing a dos filesystem despite > the verification errors, and it seemed to work. Yes, because most metadata is stored at the beginning of the disk. So directory, etc will display fine. Files are also stored starting from the beginning, so you won't see problems unless you make the disk almost full. > I then tried fdformat, having used setfdprm to set "hd". This time it worked > and passed verification. Badblocks also ran without error. really weird.... Normally, for a given disk, only one of hd or dd should work (depending on the presence of the density select hole). Unless some drives use different criteria to switch between HD and DD. > I am not sure what to make of all of this, but I wonder if my initial > attempts to format with fdformat without checking that the density was > set to "hd" may have written some dense data to the floppy (well, several > floppies) which caused problems later. > > Whatever the case, it does suggest that the problem may be with fdformat > with is in util-linux rather than fdutils. So perhaps this report should > be re-assigned? > > ael Alain -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
