Unknown format capture

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SunDown79
Posts: 13
Joined: Tue Jun 09, 2020 4:57 pm

Unknown format capture

Post by SunDown79 »

Hi,

So first of all, I know very little about formats, sectors etc so please bare with me ;)
I've been dumping MFM format disks without any problems, even some weird formats produce something.
But now I have this HD 5.25" floppy which reads "Wangtek Diagnostics Software" and I cant really get anything out of it.

The text on the floppy doesn't mean that it is still the contents, it could have been reused for something else (to make it harder)

When I just open the image with an editor I do see some things that seem to be PC/MS-DOS/Windows related, like the word EXCEL.EXE and CARPOOL.XLS but no luck in getting it to some workable img files.

I have uploaded the stream, cpt and an img attempt here : https://gofile.io/d/xgL5N9
Probably best to ignore the img file as that obviously isn't working.
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brightcaster
Posts: 379
Joined: Fri Nov 08, 2013 10:48 pm

Re: Unknown format capture

Post by brightcaster »

Looks like a standard MS-DOS 1,2Mbyte floppy (80 tracks, 15 sectors 512 Byte each) but in very poor condition!

David
SomeGuy
Posts: 311
Joined: Wed Feb 18, 2015 8:18 pm

Re: Unknown format capture

Post by SomeGuy »

Does the disk have a hub ring? If so, then someone tried to format a 360k disk to 1.2mb. That, of course, does not work and makes a mess.

It has certianly been reformatted at some point with a tool to "maximize" available space, as I see some left over double density tracks on the inner most tracks (80 and 82 that are normally unused). This also suggests this may realy be a low density disk.
SunDown79
Posts: 13
Joined: Tue Jun 09, 2020 4:57 pm

Re: Unknown format capture

Post by SunDown79 »

Well the physical disk is for sure a HD disk, the label on it proves that (Dysan 100, DS/HD)(I have never seen anyone transferring those labels ;) )
The disk actually looks and sounds really good but then again, I suppose that doesn't mean a whole lot.
Could it be that someone has used fdformat on the disk (https://en.wikipedia.org/wiki/2M_(DOS) and https://github.com/christoh/fdformat) ? That uses 82 tracks it seems and was used on DOS systems
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brightcaster
Posts: 379
Joined: Fri Nov 08, 2013 10:48 pm

Re: Unknown format capture

Post by brightcaster »

No, the tracks 80 to 82 are usual DD format with 9 sectors while the tracks before are HD with 15 sectors. The programs you mentioned are also minimizing gaps to put more sectors on each track...

The first 20 tracks are filled with software (MS-DOS) for tape drive diagnostic (which could be wangtek), as can be seen in the ASCII extracts. This files have been written with a usual floppy drive/controller system and not with a professional disk duplicator!

The floppy was also formatted with the /s option thus contains entries for IO.SYS and MSDOS.SYS files for MSDOS 3.3 (which was in common use around 1987/88).

David
SunDown79
Posts: 13
Joined: Tue Jun 09, 2020 4:57 pm

Re: Unknown format capture

Post by SunDown79 »

Hmm, weird, now it reads just fine as MFM, HD.
Did set the RPM to fixed 360 but its been using that automatically all the time.
Ow and set the tracks to 80 eventhough DTC still captured all 83 tracks.
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SomeGuy
Posts: 311
Joined: Wed Feb 18, 2015 8:18 pm

Re: Unknown format capture

Post by SomeGuy »

Could have been a dirty heads then. Also when dumping 5.25" disks, it is important to have the density line set to match the disk. Very easy to forget. RPM value is sometimes needed for decoding/making sector images, but is not needed for flux-only dumps.
SunDown79
Posts: 13
Joined: Tue Jun 09, 2020 4:57 pm

Re: Unknown format capture

Post by SunDown79 »

Its actually a strange thing with the settings in the graphical interface
Did some more analysis and if I dont set the RPM hard to 360 it won't find anything (eventhough the output does report 360RPM). If I do set the RPM to 360 it works just fine.
Its probably just one of those things :)
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ZrX
Posts: 649
Joined: Tue Dec 06, 2011 9:09 pm

Re: Unknown format capture

Post by ZrX »

The output is likely showing the reported speed of the drive used to read the disk, but you have to set the disks target systems speed for the actual analysis separately, usually 300 (default) for DD-floppies and 360 for HD-floppies.
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