7 Jan
2013
7 Jan
'13
6:38 a.m.
On Saturday (01/05/2013 at 02:06AM -0800), r.stricklin wrote:
Howdy folks.
I have a handful of 5.25" floppy disks for an Ohio Scientific C1, which I would like
to image. Anyone have any info on this disk format, or know of a tool that can read them?
They don't appear to be in a WD177x-style format... at least not one intelligible to
ImageDisk or Tim Mann's catweasel tools. There is at least one C1 emulator out there
with support for disk image files, so I have some hope somebody's already done the
dirty work for me.
If nothing already exists, low-level info on the format would be awesome as then I'd
have something to work with, trying to extend Karsten Scheibler's catweasel tools.
A few cursory trudges through t3h Googles have borne little fruit so far.
I think you will find that the C1 used an async UART (MC6850) and a PIA
(MC6820) to interface to the floppy drives. The drives were typically MPI
(Control Data's disk division) drives that had the data separator built
onto the drive. Over the years there were lots of articles about building
improved data separators but I think the original async UART connecting
to the drive's READ and WRITE data paths remained the same design.
Weird / unique and definitely not compatible with any WD17xx format as
you mentioned.
There's good stuff here,
http://www.osiweb.org/
including schematics of the 470 floppy interface card that is probably the
origin of all of it,
http://www.osiweb.org/manuals/470.pdf
Chris
--
Chris Elmquist