Any Kryoflux, Discferret, Catweasel, or other floppy flux images wanted

Fred Cisin cisin at
Mon Oct 10 19:42:25 CDT 2016

> On Mon, Oct 10, 2016 at 7:22 PM, Al Kossow <aek at> wrote:
>> You haven't actually decoded it, you've just captured flux changes.

On Mon, 10 Oct 2016, Santo Nucifora wrote:
> If I am not mistaken, I thought that's what Eric was requesting in his
> original message.

Yes, I believe that what Eric is working on IS the decoding of 
flux-transition disk images.  In particular, those from disk recording 
systems other than WD/NEC FDC compatible MFM.

>> How do you know what is there is actually correct?

Until software is created to write it back to disk in its original format, 
and test it in the original machine, we can not be sure.
HOWEVER, if Eric succeeds in decoding the Victor 9000 (aka Sirius) 
recording format, then we can look at the content of the disk and get 
reasonable assumptions.

> I don't because I am new to the Kryoflux but the log looks okay so I was
> hoping Eric would know if this was useful.  I do know the disk that the
> flux stream was taken from works because it's original and works in my
> Victor 9000.

I would not have too much confidence in that log.
But, those files, if they turn out to be good, seem to be what Eric is 
asking for!

>> I'm also puzzled when you refer to "IMD"
>> Dave Dunfield's utility?
> I am referring to what the "fluxtoimd" GitHub page README file states.  It
> says " is a Python 3 program to read floppy disk flux
> transitions images, demodulate the data, and write the data to an ImageDisk
> image file".
>> That won't work on a Victor 9000 disk
> I was curious about that but I'm willing to give anything a try if it helps
> the preservation process.

Therein lies the confusion.
IMD is a program, by David Dunfield, to extract the sector contents from 
disks that are compatible with WD/NEC FDC.  It appends the content from 
the second sector to the end of the first sector, etc. to create a file 
containing all of the user content, but stripping out all of the sector 
headers. (The inter-sector material and the track format is already 
stripped out by the NEC FDC).
It is the content of all of the sectors, in a documented file format.

What Eric is working on is software that can decode disk formats that are 
NOT necessarily WD/NEC FDC compatible!  And writing a file similar to 
the one created by IMD.

That will most certainly NOT then be convertible by IMD into a Victor 9000 

However, OTHER software, that understands the file systems could then 
extract files.  For example, if it is successful, then it might be 
possible to take the Victor9000 IMD file produced by fluxtoimd, run it 
through IMD to write that content onto a disk in a WD/NEC compatible 
format with similarities of parameters other than encoding (eg. 
Chromemco?), and then read files from that disk using XenoCopy 
or equivalent.


Sorry, but I am not likely to get around to adding IMD file support, nor 
flux transition support, to XenoCopy.

Eric is far more productive than I am.  Perhaps one day, he might write 
something with those capabilities.

Grumpy Ol' Fred     		cisin at

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