Re:A Long Adventure: Repairing Ultra-Rare NTSC Amiga Ultima 6
by pronoiac on Monday April 08, 2019 @12:26PM
(#19606643)
Heads up, store.discferret.com isn't resolving.
Re:A Long Adventure: Repairing Ultra-Rare NTSC Amiga Ultima 6
by philpem on Monday April 15, 2019 @05:14AM
(#19664110)
The store closed years ago. I was working 7am-6pm for a long while and just didn't have the time to put in.
I still have about a dozen boards and a few components, actually. Look me up on Twitter (@philpem) or Mastodon ([email protected]) if you're interested in a board, my usual offer is "beer money plus shipping" :)
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.