[HP41] mcode question polling point entries

[MeindertKuipers]

In hindsight, we could have known this all. When writing HP41 mcode I usually have the HP41CX Programming Handbook open, and take a look at page 16 (in the attachment). So this info was very close to me all the time (.. sigh ..). It cleary says the logical keycode is in nybble 1 and 2 of N. Now maybe find a way to save just these two nybbles.