Because only '0' works (and nothing else) I suspect that's an Easter egg Casio left in the calculator. If you do attempt this hack again before performing the 'matrix' hack, you can get some weird LCD segment issues, or the calculator may just switch off. There wasn't any problem running Matrices or vectors on the fx-82MS; when I performed the hack it would work as a full fx-570MS (albeit temporarily).

The total code size is given at the end of the compilation thanks to the cmake-arduino tool, and it's size is ~886bytes. I guess we're kinda taking the guy's word for it that this is an optimal hack, and that within this button-mashingmadness is not actually a much simpler secret backdoor key combothat was left by the programmer.I know it’s been two years and you probably forgot, but, do you remember if you managed to solve either matrixes or vectors on your fx-82ms? You can purchase this plan only for devices which have AT LEAST 1-YEAR manufacturer's warranty valid in India. There are more pins (keyboard combinations) that were actual buttons in the calculator, so he analyzed that and found that some combinations can be triggered to directly activate extra modes from the superior model.

Just throwing that idea out there, because like you my mind boggles at the amount of work to create this if it really is a stack-smashing exploit (which I agree it appears to be). I scraped away a bit of the coating on pin 90 and found it was tied to the negative terminal or ground on the calculator. I've encountered this testing pattern (seven keys on a diagonal) on Chinese clones like Brilliant BS-130. But I pressed 8 instead of 9 and i went through a similar display check and version, after those I ended up to a screen displaying seven numbers.that would be rather handy and make life easier as you could compare the wire bonding between different models. But But Casio kept extending this line, turning it not into just a model number but a whole calculator series. CASIO has developed a brand new scientific calculator circuit in the end of 1980s, which computes transcendental functions at much higher speed. The fx-82l variation came fitted into a hard plastic case which completely enclosed it protecting it well.