Problem with writing disks back to FDD

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duddie
Posts: 6
Joined: Fri Sep 10, 2021 5:29 pm

Problem with writing disks back to FDD

Post by duddie »

Hi, I spent a lot of time trying to write a working image back to disk. Unsuccesfully. Probably I am doing something wrong, because every time I get the same result. I have tried two different FDDs (both brand new), different power supplies, different cables. Even different hardware (I tried also SuperCard Pro). Please find attached visualisation of the images - one with green tracks (works in emulator), second - written back to disk (not working). Image looks always the same, what makes me thinking that it is a problem with a method, not with the hardware. Please help.....
I can share images, please send me an e-mail or PM (they are big).
Attachments
Image ok.png
Image bad.png
brightcaster
Posts: 476
Joined: Fri Nov 08, 2013 10:48 pm

Re: Problem with writing disks back to FDD

Post by brightcaster »

You can only copy index aligned floppies! On you original floppy the tracks start anywhere (by chance). So the sectors which cross the index (yellow areas at the right) can't be written without errors....
Caveat:

- Any side to be written must be synced to side 0 index, there is no write
splice/track gap detection.
https://www.kryoflux.com/download/DTC_2.50_addendum.pdf

David
User avatar
mr.vince
Posts: 2215
Joined: Tue Oct 05, 2010 5:48 pm

Re: Problem with writing disks back to FDD

Post by mr.vince »

If the format is known, you could e.g. turn this into a sector dump file and then convert back to RAW. This process will re-align the track data to start at the index. Or you could write a script to detect gaps and rotate the raw file data as needed.
duddie
Posts: 6
Joined: Fri Sep 10, 2021 5:29 pm

Re: Problem with writing disks back to FDD

Post by duddie »

You are right. I used Splice option for creating this dump (in Supercard Pro), because Index option didn't work in emulator, so I assumed that I must try other option. I have also RAW version created by Kryoflux. Diskette is in Amiga format, however, it contains a copy protection on track 80 side 0. I cannot convert it to ADF then. How should I proceed with my RAW file? Thank you in advance!
SomeGuy
Posts: 348
Joined: Wed Feb 18, 2015 8:18 pm

Re: Problem with writing disks back to FDD

Post by SomeGuy »

Ideally you would want to use a tool that analyzes the tracks to identify the beginning and end, and re-aligns them. However, I am not aware that such a general tool exists.

I'm not too familiar with Amiga disks, but an approach I would at least try is going ahead and converting to a sector image (.ADF?), then using a tool like the HxC software tool to export the sector image back to a kryoflux stream. Then copy the copy protected track 80 side 0 .RAW file from your original preservation stream dump over the one in this copy. This should at least result in the data area being readable.

It is possible that the protected track may also need re-alignment. The HxC software tool disk viewer does have the ability to let you manually rotate a track, that you can also then re-export to a kryoflux stream. But I don't know how well that actually works.

Of course, it is possible that even if you manage to copy the bits to the right place, the protection may still fail, because that is what copy protection does. :)
brightcaster
Posts: 476
Joined: Fri Nov 08, 2013 10:48 pm

Re: Problem with writing disks back to FDD

Post by brightcaster »

Can you upload a raw dump (at least of track 80, side 0) somewhere into the webspace and post a link here?

David
duddie
Posts: 6
Joined: Fri Sep 10, 2021 5:29 pm

Re: Problem with writing disks back to FDD

Post by duddie »

Dump of that disk is here: (it was, but it has been moderated and deleted)
brightcaster
Posts: 476
Joined: Fri Nov 08, 2013 10:48 pm

Re: Problem with writing disks back to FDD

Post by brightcaster »

Please try to write the attached (alligned) kryflux raw dump...

David
brightcaster
Posts: 476
Joined: Fri Nov 08, 2013 10:48 pm

Re: Problem with writing disks back to FDD

Post by brightcaster »

Actually I don't know how to align track 80 properly! Here is a second version with the write splice exactly within the index pulse and not after it...

David
User avatar
mr.vince
Posts: 2215
Joined: Tue Oct 05, 2010 5:48 pm

Re: Problem with writing disks back to FDD

Post by mr.vince »

Please, we'd like to avoid any discussions about piracy and stuff. We all know it's old software but the law is different. When people post their personal data in public, it's one thing (I would not do either). But commercial stuff can cause trouble. If it's just a track to outline something, this could still be interpreted as fair use (to study and learn).

Please post such images in private (e.g. use the message function to exchange emails). Thanks.

I am going to remove attachments and links.
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