The picture to the right contains the value returned by getKey for each keypress. The picture is organized so that the key codes are placed where they would be on the literal calculator. You should note that the ON key (the key in the bottom left corner) has no key code, so you cannot check for nor disable it.
If you look at the key codes, you will probably notice that they actually follow a pattern: a key is represented by putting its row and column together. For example, the ENTER key is row 10 column 5, so it's value is 105. The arrow keys look like they would be numbered separately from the other keys, but they actually follow the same pattern.
In case you want to know the key codes while using your calculator, here is a simple program to use:
:Repeat Ans=105
:getKey
:If Ans:Disp Ans
:End