0:419h                   Alternate Keypad Entry

Length: 1 byte

This byte contains the progressive input of holding down the Alt key

and entering numbers from the numeric keypad. As soon as the Alt key

is released, then the numeric value stored here is stuffed into the

keyboard buffer and this byte is set to 0.

Prev:     0:418h Extended Shift Status

Next:     0:41Ah Keyboard Buffer Head Pointer