Yep. I have a Greaseweazle and a Central Point Copy II PC Deluxe Option Board (and regular). Greaseweazle is largely the way to go. It's important to use the highest-fidelity method on the best FDD with the highest SNR because using a floppy disk causes wear to the media. Age also plays a factor.
I also have TEAC (2.88M, 1.44M, 1.2M, 720K, 360K, and SCSI versions), Sony, and various other FDDs.
If you already have a logic analyzer, are interested in the details, and maybe are facing a tricky disk with physical damage or creative copy protection, TFA may be helpful. If you just need to read disks without hassle and expense, a Greaseweasle or another adapter us likely a more suitable choice.
As a great alternative there are a handful of very cheap Saleae knock-offs using the same series of Cypress/Infineon logic chips, and they work well with e.g. Sigrok.
Note that the knock-offs are clones of the original ~10 year old Salae Logic design, which also used the CY7C68013 without an FPGA (and had smaller margins than their current design, it only cost ~$100). They added the FPGA as a way of differentiating their products from the clones after they started becoming widespread.
I would suggest as the starting point to look at sigrok's supported hardware table[0].
I personally own a bunch of the cheap 8ch 24Msps saleae clones, which are typically below $10. I would recommend the one from muselab as it has open sourced its design.
The next step, the DSLogic, of which I have a 200Msps 16ch model.
I would pay excellent money to get my hands on the floppies that held my childhood programs. They're long gone.
So if you're just getting started today, I recommend you keep copies of everything you do. It's fun to go back and look at, and maintaining those copies is a lot easier to do than it was in the 80s.
Would not the best way to scan a deteriorating? floppy disks is with a magnetic flux measuring tool that flies very close to surface of floppy , but not touching the floppy. Recording the analogue signal, generated a require a big storage space .....
That's what people do with tools like Kryoflux; the head of a floppy drive doesn't touch the disk, it floats above it and picks up the magnetic flux. https://www.youtube.com/watch?v=UxsRpMdmlGo covers a lot of it.
Looks like this would require ?3? orders of magnitude higher resolution to start resolving data on floppies. Least dense DD disk is ~6000 bits per inch, ~240 bits per mm.
Special in what way? The most special thing about Kryoflux was their EULA claiming _every bit of data imaged with Kryoflux hardware belongs to Kryoflux_
The graphs would be easier to read for somebody not already familiar with floppy drives if the signals (e.g. Step, Index0) were marked with direction, i.e. is it input to the FD or output from it.
Then there's the (several) formats of tracks and sectors, which are left out of scope.
Mature open-source alternatives include GreaseWeazle[0] and FluxEngine[1].
They are also cheap and effective, based on off-the-shelf parts.
0. https://github.com/keirf/greaseweazle/wiki
1. https://cowlark.com/fluxengine/index.html