[Coco] CocoSDC won't stay off

[Joel Ewy]

On 12/02/2014 09:43 PM, John Goerzen wrote:
> abqpenmaster <abqpenmaster at ...> writes:
>
>> I had similar experience.  Tried every combination of backup, copy, drive
> on & off but it wouldn't copy to
>> sdc.  Maybe we just use a card reader on a PC to set up files? ??
>>
> Well, I sort of did, but the point of all this is to get data off my old
> floppies into a format (.DSK files that an emulator can run, or that I can
> later copy back to real floppies) that they can be preserved.
>
> I did most of that using RETRIEVE.EXE on a DOS PC, but what I have left are
> a stack of disks with I/O errors from RETRIEVE.  I want to see if (1) I
> could copy them using BACKUP on a real CoCo, and (2) failing that, I can
> copy file-by-file as many files as possible.

Hey John,

You might take a look at your floppy disk media on the ones with I/O 
errors.  I have read about disks getting dirty with (mold?) that is 
visible on the surface of the disk.  Some advise that the disk is 
irretrievably ruined at this point.  Others have reported successfully 
cleaning the surface by removing the disk from its sleeve and gently 
washing it, then returning it to the sleeve for data recovery.  See this 
thread for some detail: 
http://www.vintage-computer.com/vcforum/archive/index.php/t-14308.html

My personal experience is that I have successfully cleaned some old CoCo 
disks that had gunk on them, using cotton swabs through the disk window, 
very gently, a window's width at a time, rotating the disk in the sleeve 
by hand, using the index hole to see when I'd moved through the entire 
disk.  One might argue that this should be saved until the absolute last 
resort.  On the other hand, others on this list have argued, and this 
matches my experience, that the crud that gets on the floppies can 
dirty, or possibly damage, the disk drive heads, which may be even more 
precious than the floppy disks themselves at this point.  I wouldn't do 
this on disks that weren't visibly dirty.  But I would definitely do it 
on disks that look like this: 
http://www.classic-computers.org.nz/blog/images/08-9-20-appleII-bad-disks.jpg 
before putting them in good drives.

I haven't tried my CoCoSDC in an MPI with a floppy controller yet, so I 
can't speak to that.

JCE


> I discovered also that the CoCo COPY command doesn't work right.  Or rather,
> it works fine for really small files, but not for big files.  I almost
> wonder if somehow SDC DOS is loading into a part of RAM that the BACKUP and
> COPY commands are overwriting?  A total stab in the dark, but it sure seems
> that way.
>
>
>