Need advice on how to recover 5.25" floppy

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harlus
Posts: 16
Joined: Wed Jan 16, 2019 7:06 pm

Re: Need advice on how to recover 5.25" floppy

Post by harlus » Thu Jan 31, 2019 2:18 pm

Ok, thank you again.
Now I'll wait for my kryoflux and let's see what happens.

harlus
Posts: 16
Joined: Wed Jan 16, 2019 7:06 pm

Re: Need advice on how to recover 5.25" floppy

Post by harlus » Tue Feb 05, 2019 3:04 pm

I received my kryoflux and I started to test it with some disks.
It seems it's working good, the only "strange" think it's that I often see "orange" sectors with the "additional information on header" warning, but probably it's normal.

Just one question: it's there any sequence to follow when turning off the kryoflux? In the quick start guide there is a precise sequence about the turning on sequence, but no mention about the turning off.

SomeGuy
Posts: 222
Joined: Wed Feb 18, 2015 8:18 pm

Re: Need advice on how to recover 5.25" floppy

Post by SomeGuy » Wed Feb 06, 2019 2:05 am

Yes, those orange header warnings are normal for user data disks. They are important only if you are archiving an original professionally master software disk, as that indicates a user may have written to the disk, altering the contents.

I'd expect the proper power down sequence to be the reverse of power up. Just don't disconnect the ribbon cable or any added grounding and you should be fine. (I just power my drives from my PC's power supply so it all gets turns on/shut off at the same time).

harlus
Posts: 16
Joined: Wed Jan 16, 2019 7:06 pm

Re: Need advice on how to recover 5.25" floppy

Post by harlus » Sun Feb 10, 2019 12:09 am

I dumped about a half of my disks, kryoflux is working very well.
I have only a small doubt: i noticed that the generated .img images have a size of 720kb, but i use 360kb disks. Is it normal? I selected "MFM sector image" as suggested.

brightcaster
Posts: 200
Joined: Fri Nov 08, 2013 10:48 pm

Re: Need advice on how to recover 5.25" floppy

Post by brightcaster » Sun Feb 10, 2019 12:11 pm

Looks as If you are decoding to 80 Tracks instead of 40....

David

harlus
Posts: 16
Joined: Wed Jan 16, 2019 7:06 pm

Re: Need advice on how to recover 5.25" floppy

Post by harlus » Mon Feb 18, 2019 10:04 am

Another question: is it possible to know the relation beetween files and tracks?

For example, to know that "tracks 1.0 contains parts of files a.txt and b.txt", or vice-versa "file a.txt is stored in tacks 1.0 and 2.0".
It would be useful to know which files are stored in demaged sectors.

harlus
Posts: 16
Joined: Wed Jan 16, 2019 7:06 pm

Re: Need advice on how to recover 5.25" floppy

Post by harlus » Mon Mar 04, 2019 9:19 am

harlus wrote:
Mon Feb 18, 2019 10:04 am
Another question: is it possible to know the relation beetween files and tracks?

For example, to know that "tracks 1.0 contains parts of files a.txt and b.txt", or vice-versa "file a.txt is stored in tacks 1.0 and 2.0".
It would be useful to know which files are stored in demaged sectors.
I found a "partial" solution for this: if you dump the same disk 2 times, and then you do an hex compare of the two resulting images (using a software like Beyond Compare or similar), the differences will be in the demaged sectors and you can have an idea about what data are demaged (obviously it's more easy if they are text files or "visually readable" files, if they are .exe or similar it's more difficult).





In the meantime i've dumped all my dos disks, and fortunately all the "important" data are safe. Obviously some disks are demaged, but i used to do backups of important disks, and it helped a lot. However i'll try another time to re-dump the demaged disks, while i'm at it.

I also found about ten commodore64 disks, and i'd like to dump also those. Which format should i use in this case? "MFM sector image" or another one?
And how can i run the software I dump? They are mainly games. For dos disks i used dosbox, is there some good emulator also for C64?

harlus
Posts: 16
Joined: Wed Jan 16, 2019 7:06 pm

Re: Need advice on how to recover 5.25" floppy

Post by harlus » Fri Jun 14, 2019 11:28 am

harlus wrote:
Mon Mar 04, 2019 9:19 am
I also found about ten commodore64 disks, and i'd like to dump also those. Which format should i use in this case? "MFM sector image" or another one?
And how can i run the software I dump? They are mainly games. For dos disks i used dosbox, is there some good emulator also for C64?
Any idea about this?
Is my floppy reader (FD-55B) good to read c64 disks?
They are mainly original disks, i don't know if the "flippy" thing is needed.

SomeGuy
Posts: 222
Joined: Wed Feb 18, 2015 8:18 pm

Re: Need advice on how to recover 5.25" floppy

Post by SomeGuy » Fri Jun 14, 2019 3:06 pm

The kryoflux can dump C64 disks either as a preservation stream file or in G64 format. G64 is used by some emulators.

I don't have any C64 disks myself, so I don't know if the G64 format supports copy protected disks or how well, or if any current emulators have support for kryoflux flux stream dumps.

The FD-55B is a 360k drive, which theoretically should be all that is needed. However, unless I am mistaken, the kryoflux demands that you use a 1.2mb to dump G64 format. I know it does that for Apple II disks. The reasons are copy protections can use half tracks on these platforms, and some 360k drives don't handle GCR well.

What you can TRY then, is to dump the disk as a kryoflux preservation stream, renumber the tracks to 0, 2, 4, 6... and then feed them back through the KF using the stream file as the source and G64 as the output format. When I have tried that with Apple II disks the first few tracks will appear bad due to GCR filtering issues, but a 360k Teac may work better than my 360k Fijitsu.

If any of the disks are formatted as "flippy" you will either need a flippy modded floppy drive, or you will need to punch a second index hole opening through the disk jacket (not the disk cookie!).

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