Upvoted, but what the hackers and hobbyists was threatening was the entire viability of the calculators.  Here's why.<p>TI's generally pretty friendly towards people tinkering with the calculators.  But what they were doing was breaking the signing keys of the operating system, so a teacher has no idea what the hell's running on a student's calculator at test time.  No one wants that, so that calculator becomes forbidden.  (The TI92 had a keyboard, and when people realized how easy it was to copy questions off, it became forbidden the next year.  Result: any high schooler had a $200 calculator useless for tests.)  Enough calculators become forbidden, people lose trust in the brand, and then they stop buying the calculators, which brings the whole system down.<p>For $100, why tinker with a Z80 processor when you can get a SheevaPlug?