"With rare, old media like that, the best chance to preserving them is reading the raw magnetic flux data with specialized equipment"
Kryoflux is great for that. https://www.kryoflux.com/?page=kf_features
Kryoflux is great for that. https://www.kryoflux.com/?page=kf_features
(Full disclosure: I'm one of the guys behind Discferret but it hasn't seen much dev work recently due to lack of time on my part)
That's interesting i was not aware of this project. I'll take a further look asap. Is there some feature/comparison sheet with Kryoflux available ?
It'll do exactly what a Kryoflux can do, including flux-transition-level read and write. (I'm not sure if the Kryoflux can write). The big differences are that it has a complete Shugart drive interface which matches what floppy drive datasheets advise -- so it's fully open-collector, with the right type of gates.
This also makes it very flexible -- it's been used to read ST506 MFM/RLL drives and decode the resulting output. It's been connected to NEC 8-inch drives with non-Shugart interfaces.
Its only major problem was that it was expensive - about $150 per unit. You could probably get that down a lot by using a more appropriate FPGA. If I did it again, I'd probably use a Lattice MachXO and the Yosys/Nextpnr toolkit, and possibly an STM32 microcontroller.
Practically speaking if you didn't need Winchester support, you could probably use the STM32's timer and PWM peripherals with DMA reload, leaving a single-chip solution with a bit of LSTTL for the drive interface.
I still have about a dozen boards and a few components, actually. Look me up on Twitter (@philpem) or Mastodon (m0ofx@mastodon.social) if you're interested in a board, my usual offer is "beer money plus shipping" :)
I thought about using Kryoflux in the past, but their licensing is a complete non-starter for me. I'm not going to purchase hardware and license software that limit what I am allowed to do with it.
I want to do a redesign with more cost-effective components (an STM32 Nucleo and a shield or Morpho backpack is one idea I'm considering).
I do have some PCBs left over, a bill of materials and can give you some guidance with part substitutions if you want to DIY one. Feel free to drop me a note on Twitter (@philpem), Mastodon (https://mastodon.social/@m0ofx) or email (via www.philpem.me.uk) if you're interested.