DrCoolZic wrote:As described in my document I am also trying to differentiate “sector write splice” from “track write splice”. To be able to make the distinction between the two requires high-level analysis. The reason for detecting sector write splice is to be able to detect if a FD has been modified (tampered).
That would be nice, but I guess you know that is not conclusive. A track can be rewritten with tools that don't produce sector write splices, even a stock Amiga can do that. That would probably be rare, unless done intentionally, but possible. And some original disks have multiple (sector) write splices, or at least it was recorded in a way that it seems so. But again, it would still be a very useful feature nevertheless.
For the protections present on track three, I need to improve Aufit, because this track used a very smart mechanism that I have never seen before: Each sector contains two ID_field in front of the Data_field! We have exactly 30 bytes (post_id_gap=7 + id_field = 6 + post_id_gap=17) from the end of the first ID_field to the data_field. This is less than the maximum 43 bytes in DD allowed by the WD1772 to correctly read a sector. I have not yet tried to read this tracks under emulation with the WD1772, but in theory you should be able to read the same sector with two different id (sector 2 and sector 12, sector 3 and Sector 13, etc.).
No. You can read the sector with the first header, but not with the second. The second header is too close to the data mark. I am quite certain that this is present on other French releases.
As far as I understand this protection was produced ‘by hand’ (not on a duplicator) and probably on an Atari?
It was almost sure produced in house and not with an industrial duplicator. Don't know if on an Atari or not.