>How about adding a 80 cent 12C508 to your board,
>which programs your 16F877 with data from an external
>port (which you must already have). The user could
>download new firmware from you via the net, plug their
>PC into the product, the 12c508 de-crypts the firmware
>and programs the 16F877 in standard ICSP mode.
>Full security, solution fixed. This gives you the same
>functionality you are asking for now, at the expense
>of adding a tiny cheap PIC.

        So I would hack a PC into the ICSP line, read the code being program, put=
 in a nice flashy page on the internet saying Me 0wNz th1s pr0gr4m ;o) Too=
 easy ;o)

        Maybe if the 877 and the 508 would be potted...but it's an easy task to=
 break the potting compound anyway...


---8<---Corte aqui---8<----

Alexandre Souza
taito@terra.com.br
http://planeta.terra.com.br/lazer/pinball/

---8<---Corte aqui---8<----

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