Any utilities to fix or read corrupt floppies?

[thorr]

I am really happy to say that I just purchased a complete Apple IIc in good condition last night and already transferred all of my old floppies to my PC. Some of them had gunk on them that I wiped off with a micro-fiber cloth. This helped read the discs with fewer or no errors when transferring, but some even with no errors during the transfer still have issues. I also have an external floppy and both drives act the same so the drive isn't the issue.

 

I tried to copy one of my bad disks with Copy II Plus using a sector copy method if I remember correctly and it took longer to copy the disk, but it copied it without any errors reported. When I went to transfer the copied disk to my PC, it had the same exact slow downs but no read errors and one sector that had errors as before, even though it was on a different disk!

 

With one of my disks, I type 'CATALOG' and it shows a partial catalog and everything on the disk up to that point works, but after that, there is an I/O error and the files that are there but not listed don't work. I have a program that calls other files on the disk, but they don't work. It does this in the emulator with the transferred disk and on the Apple IIc. I tried ciderpress, but the files listed are the same that the apple sees and none of the missing files are there.

 

Does anyone have any suggestions to get the data copied off with multiple retries or other methods to repair the disks as much as possible? On a PC, you could keep hitting retry when trying to read floppies and eventually it would read them if you were lucky.

 

Thanks!

Mike

Edited February 3, 2017 by thorr

[thorr]

Making progress... Ciderpress can be used to copy files from bad disk images to clean good ones and files that weren't working before started working and others were partially copied. This is for disks that the catalog command completes but has issue with the files.

[Keatah]

Ensure that your disk drive heads are clean. And that speed is adjusted.

[JamesD]

Sadly, no utility can replace corrupt data from an Apple II disk.

[thorr]

Thanks. Keatah, I think the drive is fine because it is just certain disks always at the same spots. JamesD, thanks for letting me know about specific utilities not existing, but at least there are a few things that I did that helped so far. Use ADTpro to transfer what is there to a disk image, then use Ciderpress to copy files to a clean dsk image. The files are not always complete but at least they are somewhat there and sometimes all there. The original disk couldn't use them at all. Also, instead of Ciderpress, I used AppleWin to copy files from the corrupt disk image to a real one and it worked better than Ciderpress in some cases.

[Keatah]

Ciderpress still has issues with filetypes S, R, and some binary files. Always did, always will.. And "sparse" files in ProDOS fail with Ciderpress too. IMHO too many issues are related to properly detecting the correct filesize.

 

I learned early on that unless a disk is bog standard DOS 3.3 with bog standard files like from "user's groups, to just use Copy II+ to re-arrange and mix disks. So much less data loss.

[Keatah]

Sometimes a single failing sector can be attributed to a spot of mold that can be seen without the aid of a magnifying glass. You can clean it with a moist Q-Tip sometimes. Or even alcohol.

Note that a disk must be in good enough condition for ADT to read it without errors. Any errors or fudging or messing around can sometimes "create" blank areas that simply got filled in during the process. And thus are now non-valid files.

 

Note that you can use the sector-map in Copy II+ to see what tracks/sectors are used. With some chance luck you may find the bad sector is not in use by any file. And the error is therefore irrelevant!

Edited February 8, 2017 by Keatah

[thorr]

Thanks Keatah! That was very helpful information! I will mess around more with Copy II+ to see if I can copy some of the files that were incomplete with Ciderpress. The microfiber cloth did a pretty good job of cleaning the disks, but there is usually a dark patch underneath where the gunk was that I don't think would come off with any other method. I might try alcohol sometime and see though. Thanks again.

[JamesD]

Someone needs to write a utility similar to Exact Audio Copy.
That repeatedly reads data from a CD track and then uses what it thinks is the best read based on all those reads.

[+frankodragon]

When I can't get disks to read, I also use a few drops of alcohol on them and run it through the disk drive. But use it at your own risk. At most times it does work, but sometimes the drive head may wear off the magnetic coating.

[Keatah]

When I can't get disks to read, I also use a few drops of alcohol on them and run it through the disk drive. But use it at your own risk. At most times it does work, but sometimes the drive head may wear off the magnetic coating.

 

I'd only use alcohol on a q-tip to buff a spot on the disk or use it on a head cleaner disk in the drive.

[thorr]

Good tips! Thanks again. JamesD - exactly what I was thinking too.

Edited February 8, 2017 by thorr