22 Oct
2006
22 Oct
'06
12:20 p.m.
Have you found a stash of Ampro Little Boards? If
so, please
. . .
There were at least a half a dozen different brands of miniature
motherboards in that form factor. Are they all rare now? Will they all read / write FM density,
WITH A FEW EXCEPTIONS.
The x86 ones tend to be reasonable implementations of 37C65,
The Z80 ones tend to be WD 179x
and allow raw bit-level access to the
track data coming from the floppy drive, though?
No
well, the 179x (Z80 ones) have a track read, but additional MINOR
circuitry will be needed to get flux transition level access.
I think that's what we're
hoping for from a data imaging device...
As you state later, there are at least three different projects/goals
being conflated here!
1) One of the most commonly stated is "I want an external 5.25" drive".
2) I want a flux transition editor and recorder
3) I want a universal recovery tool.
Actually, there's perhaps three different projects
that would be useful to tackle:
1) Off-the-shelf imaging box using a stock FDC chip capable of MFM and FM
(with little ability to handle faulty media)
2) Custom imaging box [ which may mean scrap PC + extras ] that does data
sampling at the drive digital interface level and reconstruction ( /
deconstruction) in software.
3) Custom imaging box which hooks to the floppy drive's heads directly and
uses a DAC / ADC; essentially as option 2 but can cope with marginal signal
levels to reconstruct data.
Unless I'm completely misreading the discussion
:-)
Each participant has hold of a different part of the elephant.