Here are a couple of proof-of-concepts... (obviously you need a compliant browser to view this)
HP calculators have always been hackable.
The reason that the 12C / 12C Platinum is allowed on exams (e.g. CFP and CFA Certification Exams, and the GARP FRM Exam) is precisely because they are deemed "not hackable" by the people running the exams.
I guess professors today are a bit more savvy, but when the HP28 first came out and I asked my history professor if I could "bring a calculator" he couldn't see why not
Live within your income, even if you have to borrow to do so. -- Josh Billings