The entries with question marks were not checked in this way. In the second half of the table, translated and untranslated values are equal in all known cases, with the two exceptions 83 and 84 . One asks the controller to transmit untranslated scancodes by writing a keyboard controller command with bit 5 set and bit 6 cleared. E.g., use the command byte 45 to get translated codes, and 24 to get untranslated codes that do not cause interrupts. My MyCom laptop does not support scancode sets 1 and 3 at all.
Some laptops have special key combinations that bring one into a setup or configuration utility.
It is impossible to do anything useful, or to get out of it again, when the scancode mode is not translated Set 2. My Safeway keyboard has untranslated Set 1 equal to translated Set 2, except for the multimedia keys, where untranslated Set 1 equals untranslated Set 2. A big advantage of Set 3 is that each key generates a unique code so that one does not need to parse sequences. However, the BTC keyboard mentioned above generates e0 6f for its Macro key also in scancode mode 3. The Safeway keyboard mentioned above does not generate any codes for its multimedia keys in scancode mode 3.