Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!olivea!uunet!mcsun!hp4nl!cbmnlux!cbmehq!cbmger!peterk
From: peterk@cbmger.UUCP (Peter Kittel GERMANY)
Newsgroups: comp.sys.amiga.misc
Subject: Re: Bad sectors on a disk
Keywords: How do I mark them off?
Message-ID: <1160@cbmger.UUCP>
Date: 25 Apr 91 06:47:29 GMT
References: <3229@oucsace.cs.OHIOU.EDU>
Reply-To: peterk@cbmger.UUCP (Peter Kittel GERMANY)
Organization: Commodore Bueromaschinen GmbH, West Germany
Lines: 39


In article <3229@oucsace.cs.OHIOU.EDU> cdavis@oucsace.cs.OHIOU.EDU (Charles Davis) writes:
>
>How can I tell Amiga DOS to mark a track on a floppy disk "allocated"?
>
>My friend has some floppies with errors on them and asked me if I knew how
>to tell DOS to "skip over" the bad tracks.  I had an ol' C-64 years back,
>and remembered (not too fondly, at that :^) getting into a full-screen
>"disk editor" and manually marking off block as "allocated" in the BAM
>(Block Allocation Map) on the directory track sector 0 (what was that, track
>18 or something like that?  Does anyone out there remember that old stuff?)

The mechanism is still the same, only the BAM is now called Bitmap.
Sorry, I don't know a disk monitor with this (really nice) feature,
that allows you to mark arbitrary blocks as allocated.
Ok, there are many good disk monitors out and I don't know every of
them, perhaps there is one with this.

And it's also the same with validating: If the DOS decides that your
disk has to be validated (there is no user command for this like in
the old days, but the DOS recognizes certain errors and then starts
the validating process), then your allocated block will be freed again.
So you would have to do this procedure over again.
Therefore the better way is to not only mark these blocks as allocated,
but make up a whole file with these blocks (you have pointers to every
block in the file header block). To do this by hand, you need deep
knowledge about the disk structure to create that file header block
correctly. Perhaps there exists a disk monitor which offers this
service as a feature?

>Please forgive my naivity (sp?), but I have only had 1 of my floppies ever
>go bad on me (knock on wood!), and it was actually on an MSDOS machine at
>the time (yuk!! :( )

Wait for a HD, then this issue may become even more biting :-).

-- 
Best regards, Dr. Peter Kittel  // E-Mail to  \\  Only my personal opinions... 
Commodore Frankfurt, Germany  \X/ {uunet|pyramid|rutgers}!cbmvax!cbmger!peterk