4 Nov
2011
4 Nov
'11
11:40 a.m.
On 4 Nov 2011 at 16:39, Christian Bartsch | KryoFlux Ltd. wrote:
how about the following: You just try this for
yourself; it already
supports so many generic FM and MFM formats, chances are, a broad
range will work out of the box.
FM or MFM? Dear me, if it were that simple, I wouldn't have bothered
to even mention it. How about several flavors of GCR, hard-sectored,
or written using drives with a vendor's own PCB installed on the
drive? How about a Kodak 6MB 5.25" floppy with embedded servo?
Things are really interesting in the 8" world before the advent of
LSI floppy controllers. Often, manufacturers simply invented
something. (e.g. doesn't at least on OSI format simpy use a USART,
recording the entire track as an async serial data stream?) And then
filesystems themselves are all over the place.
It just seems to me that you're mostly concerned with personal
computer floppies; i.e., the Commodore/Osborne/Kaypro etc. types of
systems. While they may have been more populous in terms of numbers
of systesm sold, they're only the tip of the iceberg. Floppies used
in the commercial world are far more diverse in format, both in
physical data representation as well as logical filesystem
organization.
Even comparatively mundane equipment poses its challenges. Consider
low-end Brother word processors, which use either a 40 or 80-cylinder
3.5" GCR-encoded format. That's not too bad--except that Brother
didn't bother to use drives with a fixed cylinder 0 position. When
formatting a floppy, they run the head out to the mechanical stop,
step one track in and begin formatting. When reading another
system's floppies, they go to the stop, then step fractional tracks
until they get a good read of cylinder 0. I guess it saves them from
addressing alignment issues on what are very cheap floppy drives.
My offer was to see how well you could do with the same sort of job I
get routinely--as in "I don't remember what it came from, but can you
get the data from it?" or "The equipment was built in-house and we've
lost any documentation, but we need 10 duplicates of the boot
floppy".
It'd be far cheaper for me to send you a sample (media mail) than to
pay your board price and international shipping costs for something
that may or may not work.
But thank you for the offer.
All the best,
Chuck