Wow; $192 for a 5.25" floppy disk drive

Fred Cisin cisin at
Sun Oct 22 14:20:26 CDT 2006

> >>    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?
On Sun, 22 Oct 2006, Jules Richardson wrote:
> Will they all read / write FM density,

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?
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.

More information about the cctalk mailing list