osiweb.org

Has anyone ever looked into patching OS-65D or HEXDOS to use the WD1772?

This would open up a lot in terms of useability in the OSI world.

like this: http://www.ebay.co.uk/itm/SD-C-HXC-Flop ... 2a4c944eb3

Or even common or garden variety floppy drives.

Actually, garden variety drives will work with the existing interface, as long as a data separator is provided to demodulate the read data. There is no intelligence built into the drives. A 720k 3.5" drive, 1.4MB 3.5" drive, or 1.2 MB 5.25" drive should look just like an 8" floppy, if properly configured.

In fact, the maintainer of the HxC emulator indicated that the emulator should be able to handle the OSI format. That's one thing I'd like to try.

If an existing emulator won't work, then there are still options for emulation; if an external separator is reversed (to demodulate the OSI write stream) then the write floppy data becomes a simple write stream, and a microcontroller (or a PC, Raspberry Pi, etc.) could demodulate that in context of the control lines to create a floppy image, and play it back directly as a serial out stream, so the OSI interface actually may not be too difficult to do in software. In fact, a fast enough chip could just digitally demodulate the FM stream without a hardware data separator.

For machines without an existing disk interface, emulation could be accomplished by emulating the UART and PIA control registers, and translate directly to a data stream, either to a storage device such as USB, SD card, or CF card; or a data stream to a host PC.

Dave

dave wrote: 1.2 MB 5.25" drive should look just like an 8" floppy, if properly configured.

I can confirm this works fine.

dave wrote:In fact, the maintainer of the HxC emulator indicated that the emulator should be able to handle the OSI format.

Hi,

Last week .... "I am currently designing another emulator working at the pulses level and
able to accept any format without software modification.

Best Regards,
Jean-François DEL NERO"

No word yet on how far down the track this is after I sent OSI timing and format info.
I think HxC is a good way to go.

Perhaps a another thread for FDC/FDD emuluation Dave as I don't wish to hijack this. But OS65D and HexDOS disk routines are very configurable. Perhaps adopt 8" image stream as a standard ?
Mike