One of the better features of the BBC Micro is its built-in assembler. However, it requires the use of both numbers and their upper case symbols such as &, * and ". How much simpler things would have been had the BBC come complete with a numeric keypad. I would then have been able to press SHIFT LOCK and type away.
I tried to program the function keys to produce numbers, e.g. f0 = 0, f3 = 3 and so on. This worked well until I pressed SHIFT LOCK, at which all I got was blank spaces. Looking through the User Guide I saw that the function keys could be set to a new base, when in SHIFT LOCK, by *FX 226,N. Thus *FX 226,48 sets the function keys to their corresponding numbers, with f0 = 0, f4 = 4 but only when SHIFT LOCK is pressed.
At any time, then, the function keys can still be used to define functions. I now have the benefit of having a numeric keyboard of types, without losing use of the function keys.