I once attempted to make an extremely shittily done VN on my TI-89...It was great...all 4 screens of it...It had saving and loading (I made each screen another tick of a variable IIRC and just had loading as jumping to the correct variable) and it made me feel awesome...but the menu (it had save, load, quit...and something else that I can't remember I think...) was somewhat sporadic in what it was doing...no I'm joking, it wasn't sporadic, it was EXTREMELY predictable, but I couldn't figure out where I needed to fix it...in the end, it got lost to the abyss and I never knew what happened to it (not on my calculator anymore for some reason :/)...