Software-based floppy disc data separator

Fred Cisin cisin at
Sat Jun 19 13:19:58 CDT 2010

> >> IMO. There also hundreds and hundreds of disk formats out there (and
> > Certainly well over 3000

On Sat, 19 Jun 2010, Kieron Wilkinson wrote:
> I don't doubt it. It probably depends on how you are counting though. I
> tend to count the huge number of variations of "generic MFM" controllers
> as "one" main format, because we have software that intelligently
> handles it as such using automated scripting. That view may stem from
> our origins in Amiga game formats, where most are completely and utterly
> different. We're also not doing file recovery, and so don't need to deal
> with filesystem-level formats, see below.


We can certainly agree to call the IBM/WD MFM (barring weirdnesses) to be
a category of format.  For your purposes, duplicating/storing/analyzing
the physical format data, all that would be relevant among those would be
"density", number of cylinders, number of sides, number of sectors per
track, and bytes per sector.  Typical weirdnesses would include such
things as unconventional sector headers (invalid cylinder, head, sector
numbering), different physical formats on different tracks, abnormal gap
sizes and content, etc.

You also get to deal with all of the non- IBM/WD style sectors.

Chuck and I are involved in extracting the information from within the
(and none of us are involved in looking for the knowledge withing the

> producing disk images that can be verified by any integrity information
> we can find (and we don't mark them as done until we do). Given our

Hmmmm.  If you needed a third party objective test, . . .
Make two copies.  Give the original and the two copies to a hacker who
would attempt to identify which one of the three disks is the original.

One of OUR tests is to transfer a file, transfer it back, and do a byte
level comparison.

> We do indeed do analysis of inter-sector and inter-track gaps, because
> some types of copy protection use those areas.

The Amiga certainly is capable of significantly more weirdnesses of that
than we need to deal with!

> > Can it be done as anything OTHER than a hobby project?
> > There certainly doesn't seem to be enough economic incentive to put in
> > that much work.  I kept at it for years after it no longer paid the bills.
> I meant it isn't a hobby in the sense that you can do for a few hours a
> week at your leisure. I think it would have to be termed more of an
> obsession, or unpaid work, than a hobby. :)

Ummmm.  People on THIS list tend to be rather obsessive in our hobbies.
"a few hours a week"???  That's barely a casual interest, nuch less a
serious HOBBY!

Grumpy Ol' Fred     		cisin at

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