>
>> Erasing the [Code Protect] bit after (or even together with) all
>> the program data doesn't seem like stealing code...
>
>    Right, Gerhard... But how would you ensure that the bit gets
>    erased AFTER the program data?
>
>    -Andy
They are doing this already by covering the protection bits with a UV blocking
 die. (This die is
visable as a black stripe near pin 22 of the 16c73a/jw package.)  The reason why
 the chips still
erase is a small amount of UV still gets through, of course the program memory
 is VERY
BLANK by then.

? Is it likely that some UV eraser bulbs emit different frequencies and that
 could penetrate the
die they use more easly & therefor erase the eprom cells more easly. The UV
 source in my
eraser is a 4W G4T5 by GERMICIDAL, this source dose not appear to erase the
 protect bits.

regards
peter w.