Tim's own version of the Catweasel/Compaticard/whatever

From: allisonp_at_world.std.com <(allisonp_at_world.std.com)>
Date: Thu Jul 6 07:22:26 2000

> This sounds like just the thing to do. Do you have any references where
> I could read up on this kind of algorithm? I've never studied signal
> processing -- I have a mathematics and computer science background, not
> engineering -- so I've been working by intuition up to this point.
>
> (Hmm, looking at Tim Shoppa's later response gives me the keywords "partial
> response maximum likelihood" to look for. That should help.)

Tim's reference is a very good one for this. It should also lead to a few
others that will help directly. He's certainly knowledgable on this.

> a clock violation, and in that case backtrack to a recent past decision
> where the second most likely alternative was close to the most likely,
> try it the other way, and see if the result looks better. Obviously one
> can't overdo that or you'll just generate random data with a CRC that
> matches by chance, but since the CRC is 16 bits, I'd think it should be
> OK to try a few different likely guesses to get it to match.

This is a possible way to approach it. Also it would allow extracting
data from a floppy that was stapled to the wall!

Allison
Received on Thu Jul 06 2000 - 07:22:26 BST