100% safe ... NO.

The program can be retrieved. But it takes some extremely knowledgable people to do it. There are even some places that will do it for you for about $5000. The reputable ones require a statement in writing that you are the original owner of the program (but that's just for their protection, not yours).

Some of the really old chips like 12C and some 16C are much easier, and can be done cheaper.
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