VT100 D1 standard keyboard mapping
		   +------+------+------+------+   +------+------+------+------+
		   |Cursor|Cursor|Cursor|Cursor|   |Erase |Clear |Toggle|Delete|
		   |up    |down  |left  |right |   |to EOF|screen|insert|char  |
		   +------+------+-------------+   +------+------+------+------+
				 |Back  |      |   |PF7   |PF8   |PF9   |PA1   |
				 |space |      |   |      |      |      |      |
			      +--+----+---+--+-+   +------+------+------+------+
Specials                      |Enter  |Back  |     |PF4   |PF5   |PF6   |PA2   |
			      |       |tab   |     |      |      |      |      |
Ctrl g     Master reset    +--+       +------+     +------+------+------+------+
Ctrl v     Refresh screen  |          |      |     |PF1   |PF2   |PF3   |PF12  |
			   |          |      |     |      |      |      |      |
<ESC>a3    PA3             +----------+------+     +------+------+------+      +
				      |Next  |     |PF10         |PF11  |      |
				      |line  |     |             |      |      |
				      +------+     +------+------+------+------+

PF1,2, ... ,11,12 can also be got by <ESC> followed by 1,2, ... ,-,=
PF13,14, ... ,23,24 can be got by <ESC> followed by !,@, ... ,_,+
