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Has anyone tried the 2M program with ao486? It's a memory-resident program that allows formatting disks beyond the capacity of MS-DOS. Would it work with a 3.5 USB drive connected to the FPGA?
More info about it here: https://en.wikipedia.org/wiki/2M_(DOS)
I would start with the drive and the terminal/ssh to see if it shows up in dmesg
ETA: I just realized
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lshwand
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lsusbwork on MiSTer
Not likely. Such programs want direct or at least quite low level access to the drive to push the geometry beyond spec. I'm unaware of methods to directly loop a floppy drive into the AO486 as if it were physically attached to a simulated controller. As far as I know, AO486 pushes and pulls sectors from MiSTer Main and the abstraction of the drive sits there. It might be possible to use /dev/fd0 as a backing store for just a bunch of sectors, but DOS on the FPGA will never be able to address the real tracks/sectors on the drive because of the abstraction.
Bas wrote: ↑Tue Oct 22, 2024 1:17 pmNot likely. Such programs want direct or at least quite low level access to the drive to push the geometry beyond spec. I'm unaware of methods to directly loop a floppy drive into the AO486 as if it were physically attached to a simulated controller. As far as I know, AO486 pushes and pulls sectors from MiSTer Main and the abstraction of the drive sits there. It might be possible to use /dev/fd0 as a backing store for just a bunch of sectors, but DOS on the FPGA will never be able to address the real tracks/sectors on the drive because of the abstraction.
It's a pity. I have several disks formatted this way, and I would like to recover the information on them. Although after so many years, I don't think anything in this universe could read them anymore. Thanks anyway!
Karlsterio wrote: ↑Tue Oct 22, 2024 2:52 pmIt's a pity. I have several disks formatted this way, and I would like to recover the information on them. Although after so many years, I don't think anything in this universe could read them anymore. Thanks anyway!
Your best bet is a preservation-style bitcell dump and then analyze and extract from there (which is utterly outside the realm of MiSTer).
Using Linux, mtools should support the 2m format. You might need to use a "real" floppy drive and not a USB one, though.
I'd try something like a flea market or online 2nd hand site to get an ancient PC. Many of those have floppy drives. Those machines could probably read your 2M formatted disks. Any local computer museum, if there are an in your area, is probably also able to help.