>A friend of mine recently asked for my help in protecting an embedded
>system of his from unauthorized duplication.  He has designed a 16 bit
>embedded system that uses an external EEROM for program storage.  The PCB


Maybe he can use a GAL do to his address decoding, and read-protect the GAL.
That method has been used by more than one vendor that I am aware of...

Jeff Otterson
-------------
otterson@mindspring.com
Maker and user of tools
PGP key available at http://www.mindspring.com/~otterson/pgp.htm