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Re: EDD Plus Card
Alex Freed wrote:
glen herrmannsfeldt wrote:
How about writing it in verilog and loading it into an FPGA?
That's pretty much what I had in mind when asking the group if anyone
still needs it. An FPGA is a gross overkill for it, but a small CPLD
like 95XL36 will do the trick. It's just not quite clear to me the card
can still be useful.
All it does is it captures raw bits so that an FF written at 36 or 40
cycles is easy to distinguish from a regular FF. Will it help a lot to
convert protected floppies to images, assuming there still are uncracked
protected floppies out there?
To that I would only add that it also allows one to determing if *any*
nibble is written with 36- or 40-cycle timing (not just sync nibbles).
This technique ("bit stuffing") is used by some protection schemes.
Capturing (even fractional) tracks from a protected floppy is only
part of the problem of recovering its data. There was a *long*
thread regarding the representation of protected floppies over a
year ago, IIRC.
Although I still favor the .FDI format, I don't think that the current
size and "vigor" of the Apple II community would support establishing
a new "standard" image format for protected disks, and the emulators
and utilities to make them useful.
-michael
NadaPong: Network game demo for Apple II computers!
Home page: http://members.aol.com/MJMahon/
"The wastebasket is our most important design
tool--and it's seriously underused."