To: Curious

(One last question, Can anybody operate the 204 unit? Or is it safe guarded by a “key of some kind? Thanks for answering. Yes, you would be welcome at my home.)

The unit has two security systems to protect it from “most” people. One, it has a code that must be entered correctly. Second, and probably more effective now, the unit can not be used by anyone who can’t add and subtract.