Hello

Is currently possible in practice to rebuild a cut in many -more or less symmetrical- pieces a an old floppy disk and retrieve information?  

It's been possible since the '90s:
www.csoonline.com/arti...f-evidence  

Very interesting article!! Thanks  

With a floppy, each sector is self contained, and disk drives are 'dumb'. A standard disk drive will therefore work (see note below on CDs)

There may be issues with the data going out of sync (clock and data bits) about the join but as disks store so little data, manual reconstruction is not impossible. Text should be easy to recover - a Zipped file rather harder as there will be errors.

You may need hardware to do a raw track read


With a CD/DVD the reading drive is normally too intelligent and so often stops you processing a partial/badly damaged CD with a 'standard' drive.
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Michael Cotgrove
www.cnwrecovery.com
cnwrecovery.blogspot.com/ 

After reading the article, I am thinking now about other, more particular and perhaps more difficult question: If instead the entire cut floppy disk (all cut fragments were there) the researcher has only 3-4 remnant cut pieces from a floppy disk(or a few of them) around 1cm x 0,5cm each: Can be read something from these?  

- williamsonn

After reading the article, I am thinking now about other, more particular and perhaps more difficult question: If instead the entire cut floppy disk (all cut fragments were there) the researcher has only 3-4 remnant cut pieces from a floppy disk(or a few of them) around 1cm x 0,5cm each: Can be read something from these?

Realistically this is not readable.

To read a track it is easiest to spin the media at the correct speed in a drive. For that ideally you require a fragment that references to either the edge or centre of the disk. That way you stand a chance of reading the data with a standard disk drive.

To read your fragments would require some kind of microscrope to pick each data transistion.

A 1 cm length is also very short. For a 3.5" disk, the outside track is approx 22cm long, and this contains 18 sectors. The chance of a full sector (with address) is low in a 1cm length. Don't forget a floppy records transistions and not absolute 0s and 1s. It is a series of clock and data bits, on double density disks, there is not always a clock bit.
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Michael Cotgrove
www.cnwrecovery.com
cnwrecovery.blogspot.com/ 

- mscotgrove

on double density disks, there is not always a clock bit.

You sure about this? Single or double density the encoding is still MFM (assumimg a PC and not GCR on a Mac) and MFM calls for clock bits always. It's been a long time since I read a floppy at the raw level but I dont recall any difference in the way I read and pieced together double/single density disks.
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Paul Sanderson
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