Deciphering an odd floppy disk format.

Mattis Lind mattislind at
Sat Feb 13 13:05:30 CST 2021

Den lör 13 feb. 2021 kl 18:40 skrev Jon Elson <elson at>:

> On 02/13/2021 11:18 AM, Mattis Lind via cctalk wrote:
> > The longest flux lengths are interspersed in between more normal flux
> > lengths in the actual data and I get the same type of result regardless
> of
> > reads of the same track and between different tracks. But the relative
> > frequency is much much lower for the longer flux lengths than the shorter
> > ones.
> The low-frequency of occurrence flux changes may be head
> switching when the write and erase current is turned on and
> off at the beginning and end of data blocks.  So, those
> should be ignored.

Yes. I am aware of write splicing. I would imagine that the number of these
longer fluxes should be somewhere around two times the number of sectors,

I see much more than what I would I would guess is the sector count.

Wouldn't these write splicing fluxes distribute quite evenly in terms of
length, creating a noise of weird fluxes?

In this case there are quite some fluxes centered around 84. If this would
be a result of write splicing I would think the same would happen on the
RX02 disk. I cannot see any of these long type fluxes there. How can that
be explained?


> Jon

More information about the cctech mailing list