What's 09h/16h ?

09h is keyboard interrupt, the utter basic interface [1] that only gives you scancodes and that's it, 16h is the extended interface [2] that you need to deal with if you want to read/set shift and other special keys [3].

[1] http://www.techhelpmanual.com/106-int_09h__keyboard_interrup...

[2] http://www.techhelpmanual.com/228-int_16h__keyboard_services...

[3] http://www.techhelpmanual.com/58-keyboard_shift_status_flags...