No, you can't write to damaged floppy from a full disk image because (pretty much all of the time) the image will be error-free, and require the damaged sectors to hold data.
That being said many bad sectors are recoverable - reformat the floppy on a good drive. Do note DOS 6 has additional command line argument for format to try and restore the bad sectors to use, and it's not on by default. Do not use Windows (and certainly nothing past XP) to format floppies. Also you want a full format (use /U) and not a quick FAT wipe or read verification of the media.

Scan will not fix bad sectors. Nothing will fix actually damaged surface (unless it's just dirt that needs cleaning) but often the issue with old floppies is weak magnetic fields so sector headers are difficult to find/read. Fresh format (actual format, not quick read-only verification) will fix that.

To get rid of floppy diskette bad sectors (if they're not from scratches or other surface damage) search for NFORMAT.EXE and use it instead of standard DOS FORMAT.COM. I usually treat diskettes with bad sectors with strong neodymium magnet and then format them with NFORMAT.EXE and this method works fine for me.

analog_programmer wrote on 2023-09-26, 06:01:

To get rid of floppy diskette bad sectors (if they're not from scratches or other surface damage) search for NFORMAT.EXE and use it instead of standard DOS FORMAT.COM. I usually treat diskettes with bad sectors with strong neodymium magnet and then format them with NFORMAT.EXE and this method works fine for me.

Hi, It's interesting that nether reply answer my question, but both interesting. It hadn't occurred to me that bad sectors could be repaired.

How do you apply the magnet? A quick swirl over both sides or something more detailed?

Ta

ldare1000 wrote on 2023-09-26, 06:37:

How do you apply the magnet? A quick swirl over both sides or something more detailed?

I use magnet from failed HDD - fits perfectly for 3.5" diskettes. Usually I touch the magnet to one side of the diskettes's plastic wrapper/envelope/case and manually spin the magnetic disk a couple of turns. Then on the other side. And finally format with NFORMAT.EXE usually results in healthy diskette with no bad sectors. Sometimes I have to repeat this procedure more then once.

If you restore the full capacity of the diskette i.e. format it with no bad sectors, then you can write the floppydisk-image with no problems, so I've answered indirectly to your question.

analog_programmer wrote on 2023-09-26, 07:01:

ldare1000 wrote on 2023-09-26, 06:37:

How do you apply the magnet? A quick swirl over both sides or something more detailed?

I use magnet from failed HDD - fits perfectly for 3.5" diskettes. Usually I touch the magnet to one side of the diskettes's plastic wrapper/envelope/case and manually spin the magnetic disk a couple of turns. Then on the other side. And finally format with NFORMAT.EXE usually results in healthy diskette with no bad sectors. Sometimes I have to repeat this procedure more then once.

If you restore the full capacity of the diskette i.e. format it with no bad sectors, then you can write the floppydisk-image with no problems, so I've answered indirectly to your question.

That's really helpful. Thanks much appreciated

Something like this?

https://www.ebay.co.uk/itm/155214678473?mkcid … emis&media=COPY

ldare1000 wrote on 2023-09-26, 08:01:

Something like this?

https://www.ebay.co.uk/itm/155214678473?mkcid … emis&media=COPY

Yep, you can get similar magnets form a dead HDD for free.

I can’t find nformat.exe…

AlessandroB wrote on 2023-09-26, 11:40:

I can’t find nformat.exe…

Here. This is the official site of its creator.

P.S. This YT video shows similar to mine treatment of floppy drive diskettes to repair bad sectors. The difference is that the guy from the video uses some unknown to me device - "magnetic tape eraser".

Just to confirm, there aren't any Wondows 10 floppy format utils or scandisk ?

Win10 doesn't really support floppies anymore. The USB drives are treated like any other mass storage devices, except with removable media so you don't need to notify OS that you are about to "unplug" it by removing the floppy. All changes are flushed from buffers at the write time.

Frankly with each version of Windows we loose what was once considered OS or system tool, and we get... a button, if that, in exchange that is supposed to "do it all for us". The OS is forcing one solution that fits all cases on everybody. No more multiple partitions on removable media. No more choice of filesystem type or settings. More monthly paid cloud services and privacy violations. If you want control then use Linux, and probably also a dedicated DOS machine because even Linux will drop support for certain hardware eventually and then it doesn't matter if you can write or compile your own tools.

Bought a Dell D400 today, installed Dos 6.22 and have been running nformat (via USB floppy) and quite often after 2 or 3 formats the bad sectors have gone. The disks literally only had 1 or 2. Does this mean they are fine again now? Ta

Windows 6.22? Don't you mean DOS, or is this something I don't know?

A thing that I discovered with 3.5"diskettes that are starting to go bad; is that sometimes they can be made to work and be fully read, depending on how you insert them.

Depth of insertion may play a role in better head-to-track alignment...
But also, your finger should NOT hinder the seating of the diskette when you push it in (which in most cases it kinda does a bit).. so the harder the mechanism "slams" the diskette, the better. This may help the head get a bit closer to the disc.

This has helped me A LOT in recovering old files from failing diskettes.

P.S.
I think it's also obvious that starting off with a well cleaned, well lubed, FDD unit, will give far better chances : )

debs3759 wrote on 2023-10-04, 22:54:

Windows 6.22? Don't you mean DOS, or is this something I don't know?

Makes sense. It's the successor to Windows 3.11 😅

B24Fox wrote on 2023-10-04, 23:24:

A thing that I discovered with 3.5"diskettes that are starting to go bad; is that sometimes they can be made to work and be full […]
Show full quote

A thing that I discovered with 3.5"diskettes that are starting to go bad; is that sometimes they can be made to work and be fully read, depending on how you insert them.

Depth of insertion may play a role in better head-to-track alignment...
But also, your finger should NOT hinder the seating of the diskette when you push it in (which in most cases it kinda does a bit).. so the harder the mechanism "slams" the diskette, the better. This may help the head get a bit closer to the disc.

This has helped me A LOT in recovering old files from failing diskettes.

P.S.
I think it's also obvious that starting off with a well cleaned, well lubed, FDD unit, will give far better chances : )

I think this makes a lot of sense. I have previously found disks on some laptops read with no bad sectors but then on another laptop there are bad sectors.

I also discovered that on one of my laptops if I'm drawing power elsewhere, for example I use a PS/2 Infrared mouse that the Floppy Drive is pretty much unusable and Scandisk will report a ridiculous amount of bad sectors. This particular laptop is having new capacitors fitted this week, be interesting to see if that cures this.

ldare1000 wrote on 2023-10-04, 21:42:

Bought a Dell D400 today, installed Dos 6.22 and have been running nformat (via USB floppy) and quite often after 2 or 3 formats the bad sectors have gone. The disks literally only had 1 or 2. Does this mean they are fine again now? Ta

I'll give one trick that I use with NFORMAT to get rid from bad sectors with fewer format cycles. Use some non-standard bigger capacity for formatting, then again standard capacity formatting i.e. alternate them.

Deunan wrote on 2023-09-27, 18:51:

No more multiple partitions on removable media

Come on, I agree with the spirit of your post, but that was first added to the Windows NT series in 2017 😁

Back to failing floppies - try a different drive before throwing away any disk, especially if it's a Panasonic (as seen in the HP Vectra VL400), in my experience they seem as reliable as original PS/2 drives...