VT300           ---+------+ +------+-------------+ +------+------+------+------+
CERN               |PF21  | | Help |             | |PF22  |PF23  |PF24  |PA3   |
D13270             |      | |******|             | |      |      |      |      |
keyboard        ---+------+ +------+-------------+ +------+------+------+------+
mapping
	       +---------+  +------+------+------+ +------+------+------+------+
tab = tab      |Delete   |  |Erase |Toggle|Delete| |PF1   |PF2   |PF3   |PA1   |
	       |         |  |to EOF|insert|char  | |      |      |      |      |
	       +---------++ +------+-------------+ +------+------+------+------+
		  |Enter  | |Next  |Back  |Clear | |PF4   |PF5   |PF6   |PA2   |
		  |       | |line  |tab   |screen| |      |      |      |      |
^g = Master       ++      | +------+------+------+ +------+------+------+------+
      reset        |      |        |Cursor|        |PF7   |PF8   |PF9   |PA3   |
^t = redraw        |      |        |up    |        |      |      |      |      |
      screen       +------+ +------+------+------+ +------+------+------+------+
			    |Cursor|Cursor|Cursor| |PF10  |PF11  |PF12  |Clear |
<ESC><tab> Backtab          |left  |down  |right | |      |      |      |      |
<ESC><del> Erase to EOF     +------+------+------+ +------+------+------+      +
						   |PF shift     |Toggle|      |
PF13,14, ... ,23,24 can be got by <PF shift>       |             |insert|      |
followed by PF1,PF2, ... ,PF11,PF12                +------+------+------+------+


