Re: EDD + CARD

[mjmahon@aol.com (Michael J. Mahon)]

eeastman@apple2.com wrote:

>That is a hardware device designed to allow you to accurately copy any
>Apple II floppy disk.  EDD is for the Essential Data Duplicator program.
>The Apple II drive does not read consecutive zeros accurately and many
>copy protection schemes use that to 'mark' the disk.  This mark can be
>very difficult to detect and duplicate.

Does anyone have any detailed info on this card and its use?  Docs,
a (reverse-engineered) schematic, software that uses it?

Reverse engineering is made a little trickier by the removal of chip labels.

And what exactly is its principle of operation?  Faster sampling of the
read signal?  Capture of the head data stream for software analysis
(independent of sync)?


-michael

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