Let me throw in my two cents on copy protection and why its
important.  I've moved this [OT], but it is related- the question is
what is the purpose of the copy protection bits, and whether is is
legitimate to defeat them (If you can).

Reverse engineering is the process of figuring out how someone else
did it.  Maybe OK, maybe not, it depends.

Plagarism is passing off someone elses work as your own.  That's
dishonest.  NOT OK.  If you are doing reverse engineering of a
product and plagarising it, don't expect any help from honest folks.

Theft is taking something away from its owner.  NOT OK.  If you are
reverse engineering a product so you can steal the development effort
by making "knock off" copies, don't expect any help from honest
folks.

With intellectual property, its often hard to know what the
"something" is, and who owns it, which is the distinction some of
us are trying to make.  But like I always tell my kids-you don't
HAVE to know who it belongs to- if you know it ISN'T yours,
that's all you need to know.

When someone new drops onto the list asking about cracking 'F84s, we
don't know what the PURPOSE is.  Some of us (including me) assume the
worst, and either ignore the post or get sarcastic with the person.

If the guy who asked about cracking a PIC gave more background
information, and so managed to convince us that he really wasn't a
crook, he might even get some help.

Now, I send product based on PICs all over the world, and I know that
none of the parts I use are unique.  Its my PROGRAM is what makes
it great (If I say so myself).  So if crooks can copy my code, there
could be knock-offs almost immediately (perhaps I flatter myself
that anyone would bother...) But that would mean a real loss of
real money.  That's THEFT.  SO, I use the "anti-theft" bits on my OTP
PICs.

Which brings me back ON topic: Is there any evidence that OTPs are
vulnerable to attack?  I know there were some infamous problems with
early OTPs and selective EPROM erasure attacks.  But the fact is
that many of us have ruined more recent /JW parts by programming
the code protects.  I suspect MicroChip buried the code protect bits
on the newer dies, or that they aren't EPROM.  I'm guessing you'd
need a Voltage Contrast electron microscope or other exotics to
defeat this.  Any comments?

Regards,
------------
Barry King
Engineering Manager
NRG Systems "Measuring the Wind's Energy"
barry@nrgsystems.com
Phone: 802-482-2255
FAX:   802-482-2272