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.
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.
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
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).
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