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Vintage dos/windows software to create .IMG floppy images?

If it uses a non standard disk geometry that means OP's machine had a non standard drive to begin with, which should be noted in the first place.

I presume this is standard Backup disk with extra checksum/metadata appended by some tool.

OP, don't use a text editor, use a hex editor, you need to remove exactly 484 bytes from that file, and if you're deleting text characters you're doing it wrong.
Try this :

Code:
dd if=doc.img of=doc.img.test bs=1 skip=484 count=1474560

Then do

Code:
file doc.img.test
 
Thanks Zare!! I'll do just that. Apologies to everyone for the timing of my replies but since I'm a new member of the forums, all of them are being moderated and we have to wait for them to be published until I get to my 10th post.
 
I'd love to post the entire file and be of better help. the only problem is that the files i'm attempting to rescue may have other people's information and I am working on the careful side.
If you want, email it to vcfblackhole at protonmail.com. This is my line of business--I routinely handle sensitive data.
 
I stand corrected of course. I just didn't mentally wire the fact of arbitrary formats while writing that. (while recently getting a new box of Olivetti branded "2MB" floppies)
 
while recently getting a new box of Olivetti branded "2MB" floppies)

FWIW, it wasn't particularly rare for HD 3.5" to say that on the box before floppies started universally coming pre-formatted. That is roughly their capacity in terms of raw flux transitions at the standard high density datarate with MFM encoding. (Likewise the the low-density disks would say "1MB", not "720K". Maybe that was more relevant in an era when alternate formats like Apple's 800K and Amiga... 880K? were more common in the real world.)

https://i.ebayimg.com/thumbs/images/g/UcUAAOSwzJ5XeCmh/s-l225.jpg
 
(while recently getting a new box of Olivetti branded "2MB" floppies)
Why the quotes around "2MB"? That's the standard "unformatted" capacity of the diskettes people usually format to 1.44 MB "formatted" data capacity. (And yes, you really can store close to 2 MB on them if you're willing to use different format. This was frequently done for multi-disk installation sets; around 1.8 MB formatted capacity was popular for those.)
 
Thanks Zare!!

You're welcome :)

In the case it's not all in the beginning (file command will report just binary data, not a disk image), use the command

Code:
dd if=doc.img of=header.bin bs=1 count=500

To extract first 500 bytes and post the file here. I would inspect the hex dump you previously posted but it's too much effort to convert it to bytes and it doesn't have the region with the OEM-ID e.g. the "IHC" thing since it's at least 400+ bytes in from what's visible in the first post.

Why the quotes around "2MB"?

Because in my case I've literally held the 2 MB labeled floppy in hand recently, formatted it to 1.44MB for normal DOS use, knew what was it all about, and still posted here that having image larger than 1.44 smells of a non-standard floppy.
Hence the quotes for emphasis.
 
Because in my case I've literally held the 2 MB labeled floppy in hand recently, formatted it to 1.44MB for normal DOS use, knew what was it all about, and still posted here that having image larger than 1.44 smells of a non-standard floppy.
Oh, I get it now.

...To extract first 500 bytes and post the file here....
I suggest that posting the first 8 KB would be better. That should avoid any personal data possibly on the image, but also work even if this is a standard 1.44 MB diskette image with a 4 KB header. (As I mentioned earlier, the size of the .IMG file is 4096 bytes larger than the data capacity of a 1.44 MB diskette.
 
I think that size difference has been misreported...
Has it? My calculation was based on the original message:

  • The file size is 1.478.656 bytes, which makes me believe it's a floppy disk image, although the IMG file itself won't fit in a floppy disk.
So: 1478656 bytes - (2 heads * 80 cylinders * 18 sectors * 512 bytes) = 4096 bytes.
 
@cjs Yes, but I later corrected the file size to 1.475.044. The reason why the original post is incorrect is because that was the number Windows reported. I later realized linux had a more accurate number, but was unable to edit the original post. Today I plan to devote some time to this again and test Norton for Windows, and other versions, then move back to manually adjusting the file if Norton doesn't do the trick.
 
@cjs Yes, but I later corrected the file size to 1.475.044.
Ah, I see. I missed that. So that's where the "484 bytes" thing was coming from.

Today I plan to devote some time to this again and test Norton for Windows, and other versions, then move back to manually adjusting the file if Norton doesn't do the trick.
If you dd bs=1 skip=484 the file, do you get a new file starting with a DOS boot sector? (The file command will immediately tell you this.) If so, you can simply loopback mount that file on Linux (see any tutorial on how to mount file images) and see what's on the image, if the rest is indeed an image of a floppy with a filesystem.
 
@cjs yeah my thought exactly... @RodCastler stay on Linux for now, it's faster to analyze binary data with console tools. If this is what we presume, you won't need specialized Windows applications to get the data.

By the way, the only post from member @Moebius, 5 years ago, regarding the ****IHC oem-id

Nothing to do with FAT per se, it's just a local modification typically coupled with last access timestamps (AT) embedded in a medium's root directory. The rumor has it that the last 3 letters stand for "CHICAGO" spelled backwards, which is the codename for the earliest Win95 release. Not sure why it spanned beyond Win95, though. Also, this behavior is not limited to Win9x alone and is present in at least all of NT-based OSs from 3.51 (presumably) to 5.1. I've had some of my dumps modified by WinXP exactly the same way. The bottomline is, this will eventually happen in pretty much any Windows version as of 1995 if a disk is not write-protected. While it may take some time for OEM ID to change (seems to depend on multiple disk access or scanning) the AT will stick to the root directory instantly on file access. A simple file copy procedure is enough to make it happen. At first only executable (.EXE, .COM) and 30kb+ file entries are targeted, but eventually all of them will meet the same fate. Again, depends on what you do.

 
Updates, updates:

I tried with Norton Disk Doctor for Windows, but no luck with that either, although I admit it was a lot of fun running that software again after so many years. And it did seem to be a logical choice. So I then moved on to the next step of the plan, and:

dd if=doc.img of=doc.img.test bs=1 skip=484 count=1474560

That was exactly it.

As it turns out, by removing that 484 byte header, the file matched a regular image file that was easily opened by Winimage and by virtualbox as well.
I am going through the recovered files now, It all seems good. Unbelievable.

I guess I'll never know which software created that strange image back then, or why did it add that 484-byte header on top of it.

I want to thank you all. Everyone who chipped in. I would have never recovered that floppy without your help and the whole process was a fun trip down the memory lane. Happy to be here, happy for your help.

yours,
Rod
 
Updates, updates:

I tried with Norton Disk Doctor for Windows, but no luck with that either, although I admit it was a lot of fun running that software again after so many years. And it did seem to be a logical choice. So I then moved on to the next step of the plan, and:



That was exactly it.

As it turns out, by removing that 484 byte header, the file matched a regular image file that was easily opened by Winimage and by virtualbox as well.
I am going through the recovered files now, It all seems good. Unbelievable.

I guess I'll never know which software created that strange image back then, or why did it add that 484-byte header on top of it.

I want to thank you all. Everyone who chipped in. I would have never recovered that floppy without your help and the whole process was a fun trip down the memory lane. Happy to be here, happy for your help.

yours,
Rod
Yeah Herne data systems had software that added a header to its floppy images because it could technically image non-dos floppies with odd parameters that were stored there by the software.
 
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