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Floppy Disk recovery

Posted: Wed Nov 10, 2021 2:52 pm
by 7homR
I'm trying to get files off an old floppy disk I have. Maxell Micro Floppy Disk MF 1-DD Single Sided, Double Density, Double Track 135 TPI.
I bought an external USB floppy drive off Amazon, but get the read error: "A:\ is not accessible. The disk media is not recognized. It may not be formatted."
I have read that this could be because old disks like this don't have a 'media descriptor byte', but I don't how to edit that without access (an old Microsoft article says to use DiskProbe, but I don't think that exists for Windows 10), nor what the specific media descriptor byte is for this particular disk. Help appreciated.

Re: Floppy Disk recovery

Posted: Wed Nov 10, 2021 10:34 pm
by fzabkar
There was a thread at Tom's Hardware where a user failed to power the floppy drive correctly. I'm wondering if that could be your problem?

Could you provide a link to the external drive?

Re: Floppy Disk recovery

Posted: Thu Nov 11, 2021 2:12 pm
by 7homR
Hi, thanks for your reply!
This is the drive:

I've tried both USB ports on my ThinkPad, and a bunch on my desktop, so I don't think it's the power issue you mention.

Re: Floppy Disk recovery

Posted: Thu Nov 11, 2021 2:15 pm
by lcoughey
The disk media may be too degraded to read and/or needs to be cleaned.

Re: Floppy Disk recovery

Posted: Thu Nov 11, 2021 3:03 pm
by 7homR
I'm not seeing the link I posted earlier: are external links permitted here?

If so, here is a link to a comment on Amazon from someone with a similar issue: https://www.amazon.com/gp/customer-revi ... B00RXEWOAA

Yes, it's possible the disk is degraded, but it would be nice if I could address this 'media descriptor byte' issue first, and then move to that.

Re: Floppy Disk recovery

Posted: Thu Nov 11, 2021 3:44 pm
by 7homR
To reiterate: from what I've read, this drive can't read this older single-sided, double-density disk because those older disks have an identification conflict. Instead of just returning this drive, though, I'm wondering if anyone knows if there is software that will let me bypass the drive's reading troubles to edit the descriptor on the floppy so that the drive will be able to read it?
Obviously, if it's a matter of degradation, this won't be possible, but I would like to try.

Re: Floppy Disk recovery

Posted: Thu Nov 11, 2021 10:26 pm
by IsoBuster
I'm very (very) rusty on the subject but there are several layers of complexity.
The floppy may have been formatted with a layout of tracks that is not supported by Windows and/or its drivers.
So that's a layer 'below' the 'user data' portion that stores the 'MBR' and (supposed) FAT File system etc.

How was the floppy created / formatted ?
Was it created with some ancient game console or special hardware, or was it formatted on a Windows system ?

Do you see the floppy in Windows via 'Disk Management' ?

If you do, and you want to edit things, start up a hex editor (run as admin) and change the byte(s) you want to change.

Also curious what IsoBuster sees on the disc (if you want to try: https://www.isobuster.com/download/ - Use free mode).