[Coco] Reading floppies with CRC error?

[S Klammer]

Sorry, my earlier reply was not even trying to answer your question...

Yes, having one out of a backup set fail, is frustrating.  Since you've
gone this far, you might get lucky tweaking the pre-amp (if one is
available) of the floppy head?  I've not done something like that in
decades...

I'm not personally aware of something under OS9 which would try to "guess"
what the sector contains and use that rather than giving up with the CRC
error.

Perhaps make an image, outside of OS9, hex edit it to recalc the CRC value
and put that back into the image?

Hope some of these thoughts might be useful; but, you've likely already
considered them... I've been outside of OS9 too long.

sk
On Aug 19, 2014 5:45 PM, "Kandur" <k at qdv.pw> wrote:

> Nick, you are talking about 'now' and the 'future',
> I agree with you 100%, but my probem is from the 'past'.
> In the good old days of the Coco-3's birth year, we had no
> SD memory cards, or DVDs, cheap HDs were were just a dream.
> We used, what we had, floppies. Interestingly, 24 out of 28
> floppies remained in excellent conditions, two had signs of wear
> and only one was bad. My guess is, that that one was an
> overused, worn out floppy when I made the archive.
> Shouldn't have used it, my fault.
> Anyway, I used to have a program, that rescued bad floppies.
> It just kept reading everything non stop, garbage and all.
> Later I had one like this to read bad CDs.
> This diskette had some Sculptor database and
> procedure files of my music collections' catalogs.
> Not terribly important, just somehow don't feel like
> writing the missing procedure sources again.
>
> Kandur
>
> Tuesday, August 19, 2014, 11:56:05 AM, you wrote:
> > On 20/08/2014 2:30 AM, Kandur wrote:
> >> Reading floppies with CRC error?
> >> http://qdv.pw/coco/?p=253
>
> >> Kandur
>
>
> > Floppies with those sort of scratches on the surface are a lost cause.
> > The disk media has deteriorated over the years that the magnetic
> > material has become flakey and unreliable to store data on.
>
> > While you may be able to recover some files off it, I ask myself the
> > question... is it worth it when almost all programs are available as a
> > DSK disk image?
>
> > Personal data is another story but that is why magnetic media needs to
> > be periodically backed up onto new media every so often...but who goes
> > to that bother?
>
> > I don't even use a floppy drive anymore. My CoCo is floppy'less. I've
> > invested in a controller that uses SD memory cards and I run disk
> > images. Backups are easily performed by copying the entire SD card to a
> > directory on my PC.
>
> > It also has Drivewire support.
>
> > Best investment I ever made for my CoCo.
>
> > Nick
>
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