sqrkl@csvax.liv.ac.uk (04/15/88)
Ever had a disk go 'unreadable' on you ? Well, read on...
My MacWrite disk decided to self-destruct the other day...so badly that the
Finder kept saying that the 'disk is unreadable' !! Having plenty of work on
it, I set myself the task of fixing it.
I first tried 'DiskExpress' which provides a Finder-like interface for
compressing/verifying/repairing disks. Unfortunately, it was TOO much like the
Finder - it claimed the disk was unreadable as well (with a remarkably similar
dialog box, I might add).
Next, I tried 'Fedit+'. I really like this program - it's great for just
hacking around, so I was quite optimistic about my chances. At least it recog-
nised the faulty disk (it just called it 'External Drive'), so I did an 'Open
Volume' on it and -BINGO- up came sector 0 of the disk. Simple investigation
found that absolute sectors 3 and 4 were unreadable, but Fedit+ wouldn't show
me sectors 3 or 4 (it stuck on sector 2 if I used Next Sector and sector 5 if
I tried Prev Sector). So I resorted to the good old 'Read Multiple Sectors' and
'Write Multiple Sectors' with buffer 0, from sector 3 and length 2 sectors.
I used 'Read Mult...', ignored the error dialog, then 'Write Mult...'. Hooray !
I now had readable sectors 3 and 4, but...they had rubbish in them.
It now dawned on me that Fedit+ had no 'Repair boot tracks/directory
structure' option, but DiskExpress DID. So I trundled back to DiskExpress,
where I got 'Disk is damaged' instead. However, DiskExpress bestowed pity on
me and this time let me mount the disk and do things with it. So I set the
'Repair Automatically' flag on and clicked on 'Start', then prayed...
My prayers were answered. On exiting to the Finder, ejecting the suspect
disk (Shift-Command-2) and re-inserting it mounted a pefect working copy of
MacWrite. One disk backup later and I had a good disk again.
So the moral of this tail is - Don't Give Up (unless you're Kate Bush or
Peter Gabriel !) on bad disks : they can be salvaged with some patience and
copies of Fedit+ and DiskExpress.
Richard K. Lloyd, ***************************************************
Computer Science Dept., * JANET : SQRKL@UK.AC.LIV.CSVAX *
Liverpool University, * UUCP : {backbone}!mcvax!ukc!mupsy!liv-cs!SQRKL *
Merseyside, England, * ARPA : SQRKL%csvax.liv.ac.uk@nss.cs.ucl.ac.uk *
Great (?) Britain. ***************************************************
"I have VERY strong opinions which are nothing whatsoever to do with the
University of Liverpool, so blame ME if I bitch about useless IBM PC clones,
even more redundant IBM mainframes and the terrible Atari ST..."FELIX@KL.SRI.COM (Felix Ingrand) (04/19/88)
>From: sqrkl@csvax.liv.ac.uk >Newsgroups: comp.sys.mac >Subject: I fixed an unreadable floppy...now you can too ! >Message-ID: <487@csvax.liv.ac.uk> >Organisation: Computer Science CSVAX (VAX1), Liverpool University > >Ever had a disk go 'unreadable' on you ? Well, read on... .... After reading your article, I was wondering if your method could work on one of this <Flame ON> <Censured> <Flame OFF> Protected Software I bought lately and whose disk became unreadable after 3 weeks... Ispend lot of time to try to recover it... No success with any soft (Mac Zap, Disk Express, Disk First Aid,...) Today, I did exactly as you described, but DiskExpress still failed to read the disk... (after the read-write of the "bad sector" under FEdit+). In a last hope, I called Disk Firts Aid (Apple)... Believe it or not, it succeed to rebuilt the disk (without breaking the protection unfortunately). I do not say that Disk First Aid is better of worse than Disk Express, but it looks like they are in some ways complemantaries. Never give up... As long as your disk is "insertable" in the drive, there is hope, try any combinaitions of Utilities... Felix
alcmist@well.UUCP (Frederick Wamsley) (04/20/88)
In article <487@csvax.liv.ac.uk> sqrkl@csvax.liv.ac.uk writes: >Ever had a disk go 'unreadable' on you ? Well, read on... > [Helpful description of using low-level utilities to revive a disk] Before you start a project like this, use Copy II or some other copy-anything-that's-there utility to duplicate the damaged disk. Your first experiment might fail and leave you worse off, so it's important to have a duplicate on which you can start over. -- Fred Wamsley {dual,hplabs}!well!alcmist;well!alcmist@lll-crg.arpa; CIS 72247,3130; GEnie FKWAMSLEY;ATT Mail fwamsley; USPS - why bother? "I was just being polite, sir" - Lt. Worf