I had a TI-84 Plus Silver Edition back in the day, and if I recall correctly, it had twice as much RAM available as the OS exposed, and you could load a third-p

I had a TI-84 Plus Silver Edition back in the day, and if I recall correctly, it had twice as much RAM available as the OS exposed, and you could load a third-party assembly program that would wire up a specific hotkey to essentially swap banks of memory. This way you could have what appeared to be a clean calculator with no programs on it, then swap over to the other memory bank and all your programs would be accessible. Even telling it to clear RAM would only clear the current bank.