Split files appearing in 5.25" disk image

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lglanville
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Joined: Wed May 24, 2017 7:48 am

Split files appearing in 5.25" disk image

Post by lglanville » Thu May 25, 2017 1:04 am

Hi all,

I'm attempting to create images of some 5.25" floppies containing text documents. The disks were created using an IBM XT and a word processor called Wordcraft. I'm able to extract some content using a 40 track MFM profile, but the documents appear to be split into three files - one file with a .doc extension, another with the same name but a .001 extension, and a third ending in 001.fileslack. DIgging down using some forensics software indicates all three files have content. I'm unsure whether it's an issue with the software used to create the files (which apparently had some form of hardware plug in DRM), the drive itself or the profile used to create the image. Has anyone come across anything similar?

SomeGuy
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Re: Split files appearing in 5.25" disk image

Post by SomeGuy » Thu May 25, 2017 12:42 pm

What file system format is the disk supposed to be, and what software are you using to extract the files? A file name like "001.fileslack" should not be possible unless you are using some fancy file extraction software that attempts to save the unused slack space at the end of a file. That does not normally contain meaningful data. ".001" could be a backup file, but if your file extraction software is creating extra metafiles, you should consult the manual for your extraction software.

I would try to check that your extraction tool properly recognizes the file system and disk size (160k, 180k, 320k, 360k, 1.2mb, or some other oddball size). For example, a problem with some very early IBM pc low-density 5.25" disks is that 160k and 320k formats use 8 sectors per track, but disk copiers would add an unused 9th sector to each track. DOS would read these disks fine, but that confuses many disk utilities. In some cases where there is a mismatch, file extraction tools may attempt to extract files, but the file will contain data from the wrong area on the disk.

I have never heard of the "Wordcraft" word processor. Even if it is copy protected, do you have a copy of this software?

A common problem with older file formats is that often the only way to meaningfully view the content is to view it with the software it was authored in. This is not always possible as the software may not be available, may be copy protected, or no existing machine or emulator can run it.

BarryB
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Re: Split files appearing in 5.25" disk image

Post by BarryB » Fri May 26, 2017 10:24 pm

Googling shows Wordcraft 20 on cartridge by UMI (United Microware Industries) for the VIC 20, you can save to tape or disk, so is it a VIC 20 save disk not IBM?

brightcaster
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Re: Split files appearing in 5.25" disk image

Post by brightcaster » Sat May 27, 2017 3:53 pm

Wordcraft was availabale for IBM, CBM and others....

http://legacy.wordcraft.com/docs/software

David

lglanville
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Re: Split files appearing in 5.25" disk image

Post by lglanville » Mon May 29, 2017 2:32 am

Thanks for the comments. I was digging into the emails using some forensic software (FTK imager) which does make fileslack and empty storage visible. This is the first time I've come across meaningful content in fileslack though. I had a go mounting the image in dosbox and got a dir listing of just the .doc and .001 files.
The disks were definitely created with an IBM XT. You can see the write protection dongles here if anyone's interested. https://en.wikipedia.org/wiki/Software_ ... ion_dongle The presence of data in the fileslack makes me think though that the issue is with the drive or the image creation.

lglanville
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Re: Split files appearing in 5.25" disk image

Post by lglanville » Mon May 29, 2017 2:34 am

By emails I mean images. :P

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mr.vince
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Re: Split files appearing in 5.25" disk image

Post by mr.vince » Sat Jun 03, 2017 8:03 am

Why not give it a try and extract the files from the image with TotalCommander and the corresponding plugins? We use this as a standard and it's working really well.

lglanville
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Joined: Wed May 24, 2017 7:48 am

Re: Split files appearing in 5.25" disk image

Post by lglanville » Mon Jun 05, 2017 5:06 am

Had a look at TC and wasn't able to extract more than what I already had with FTK. However, after some more trials and exploration, I think I've made sense of what's happening here. It appears the full text of the document is in the .001 file in plain text. Have no idea what the .doc file did in the original application, maybe handled metadata or DRM? The content in the file slack is text that's been deleted (seems obvious now). Thanks again everyone for thoughts and observations, main thing now is I know the drive and image profile are correct.

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