In article 4D2DAB97.9070206@yahoo.co.uk, Jules Richardson wrote:
Are you sure the drive is good? I just wonder if the heads are seriously misaligned, which might explain the strange format that it's seeing (or they were on the drive that wrote the disks, which might make life interesting!)
I've tried two different drives and I get the same results.
A bit more digging suggests that I'm only seeing the first sector of each cylinder as absent due to some artifact of the read process; the first sector on the second head is also MIA but ddrescue seemed to think it had read it OK.
I've read (and restored) loads of other floppies on the same hardware, so I am tending towards thinking it's a proprietary/odd format. As for why this is only the case for the first 20-30 cylinders (after the first one) is also a mystery - I tried and I can happily load sector one from higher tracks.
Of course, it could be that the normal 15 sectors should be there, but YOY would there be no sign of them? I can't read them with fdrawcmd rear and issuing multiple readid commands shows all the other sectors but not sector one.
I'll do more playing this evening, mainly using readid, and see how big the 14 sectors are.
Ian