BBC USB Keyboard Keymapping
                                                      ===========================

  +-----+     +-----+-----+-----+-----+  +-----+-----+-----+-----+  +-----+-----+-----+-----+  +-----+-----+-----+
  | &1B |     | &81 | &82 | &83 | &84 |  | &85 | &86 | &87 | &88 |  | &89 | &CA | &CB | &CC |  | &80 | &C3 | &8A |
  | ESC |     | f1  | f2  | f3  | f4  |  | f5  | f6  | f7  | f8  |  | f9  | f10 | f11 | f12 |  |Print|ScLck|Break|
  +-----+     +-----+-----+-----+-----+  +-----+-----+-----+-----+  +-----+-----+-----+-----+  +-----+-----+-----+

  +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+  +-----+-----+-----+  +-----+-----+-----+-----+
  |~ ~ £|  !  |" @ "|£ # #|  $  |  %  |^ ^ &|& & '|* * (|( ( )|) ) _|_ _ =|+ + ~|  |  | &7F |  | &CD | &C8 | &9F |  | &C2 | &EF | &EA | &ED |
  |£ £ _|  1  |  2  |  3  |  4  |  5  |  6  |  7  |  8  |  9  |  0  |- - -|= = ^|  \  | BS  |  | Ins |Home | PgUp|  | Num |  /  |  *  |  -  |
  +-----+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+-----+  +-----+-----+-----+  +-----+-----+-----+-----+
  |   &09   |     |     |     |     |     |     |     |     |     |     |{ { @|} } {|   |   |  | &7F | &8B | &9E |  | &F7 | &F8 | &F9 |     |
  |   TAB   |  q  |  w  |  e  |  r  |  t  |  y  |  u  |  i  |  o  |  p  |[ [ @|] ] [|   \   |  | Del | End | PgDn|  |  7  |  8  |  9  | &EB |
  +---------+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+-----+  +-----+-----+-----+  +-----+-----+-----+  +  |
  |           |     |     |     |     |     |     |     |     |     |: : +|@ " *|~ ~ }| &0D |                       | &F4 | &F5 | &F6 |     |
  |    CAPS   |  a  |  s  |  d  |  f  |  g  |  h  |  j  |  k  |  l  |; ; ;|' ' :|# # ]|RETRN|                       |  4  |  5  |  6  |     |
  +---------+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+-----+-----+        +-----+        +-----+-----+-----+-----+
  |         |  |  |     |     |     |     |     |     |     |  <  |  >  |  ?  |             |        | &8F |        | &F1 | &F2 | &F3 |     |
  |  SHIFT  |  \  |  z  |  x  |  c  |  v  |  b  |  n  |  m  |  ,  |  .  |  /  |    SHIFT    |        | Up  |        |  1  |  2  |  3  | &E0 |
  +--------++-----++----+--+--+-----+-----+-----+-----+-----+--+--+----++-----++-----+------+  +-----+-----+-----+  +-----+-----+-----+ ENT |
  |        |       |       |                                   |       |       | &C1 |      |  | &8C | &8E | &8D |  |    &F0    | &ED |     |
  |  CTRL  |  WIN  |  ALT  |               SPACE               |  ALT  |  WIN  | APP | CTRL |  | Lft | Dwn | Rgh |  |     0     |  .  |     |
  +--------+-------+-------+-----------------------------------+-------+-------+-----+------+  +-----+-----+-----+  +-----------+-----+-----+
  +------+-----+-----+------+--------------------------+-----+-----+-----+-----+-----+------+
  |      |     |     | &C5  |                          | &C6 | &C7 |     |     | &C1 |      |
  | CTRL | WIN | ALT |NoConv|           SPACE          | Conv| Kana| ALT | WIN | APP | CTRL |
  +------+-----+-----+------+--------------------------+-----+-----+-----+-----+-----+------+

In each key box:    +--------+
      Shifted key:  |UK US BP|   BP is BBC/JP/ECMA23     &80-&DF modified with Shift/Ctrl/Alt. Character read encoded with *FX225-*FX228.
                    |        |                           &E0-&FF added to keypad base set with *FX238. &E0 is keypad 13, &FF is Delete.
    Unshifted key:  |UK US BP|   &xx is keycode          TAB is set with *FX219.
                    +--------+



                     USB Keyboard BBC/RISC OS Keymapping
                     ===================================

+--+----+---+---+---+---+----+----+----+----+----+-----+---+----+----+----+----+
|  | 0  | 1 | 2 | 3 | 4 | 5  | 6  | 7  | 8  | 9  |  A  | B | C  | D  | E  | F  |
+--+----+---+---+---+---+----+----+----+----+----+-----+---+----+----+----+----+
|0x|    |   |   |   |   |    |    |    |    |Tab |     |   |    |Ret |    |    |
+--+----+---+---+---+---+----+----+----+----+----+-----+---+----+----+----+----+
|1x|    |   |   |   |   |    |    |    |    |    |     |Esc|    |    |    |    |
+--+----+---+---+---+---+----+----+----+----+----+-----+---+----+----+----+----+
|  |    |   |   | ~ |   |    |    |@ " |    |    |     |   | <  |_ = | >  | ?  |
|2x|Spc |   |   | # |   |    |    | '  |    |    |     |   | ,  | -  | .  | /  |
+--+----+---+---+---+---+----+----+----+----+----+-----+---+----+----+----+----+
|  |) _ | ! |" @|£ #| $ | %  |^ & |& ' |* ( |( ) |  *  |: +|    | +  |    |    |
|3x| 0  | 1 | 2 | 3 | 4 | 5  | 6  | 7  | 8  | 9  |  :  | ; |    | =  |    |    |
+--+----+---+---+---+---+----+----+----+----+----+-----+---+----+----+----+----+
|  |    |   |   |   |   |    |    |    |    |    |     |   |    |    |    |    |
|4x| @  |   |   |   |   |    |    |    |    |    |     |   |    |    |    |    |
+--+----+---+---+---+---+----+----+----+----+----+-----+---+----+----+----+----+
|  |    |   |   |   |   |    |    |    |    |    |     | { | |  | }  | ~  | £  |
|5x|    |   |   |   |   |    |    |    |    |    |     | [ | \  | ]  | ^  | _  |
+--+----+---+---+---+---+----+----+----+----+----+-----+---+----+----+----+----+
|  |~ _ | A | B | C | D | E  | F  | G  | H  | I  |  J  | K | L  | M  | N  | O  |
|6x| £  | a | b | c | d | e  | f  | g  | h  | i  |  j  | k | l  | m  | n  | o  |
+--+----+---+---+---+---+----+----+----+----+----+-----+---+----+----+----+----+
|  | P  | Q | R | S | T | U  | V  | W  | X  | Z  |  Z  |   |    |    |    |    |
|7x| p  | q | r | s | t | u  | v  | w  | x  | y  |  z  |   |    |    |    | BS |
+--+----+---+---+---+---+----+----+----+----+----+-----+---+----+----+----+----+
|8x|Prnt|F1 |F2 |F3 |F4 | F5 | F6 | F7 | F8 | F9 |Break|End| <- | -> | Dn | Up |
+--+----+---+---+---+---+----+----+----+----+----+-----+---+----+----+----+----+
|9x|    |   |   |   |   |    |    |    |    |    |     |   |    |    |PgDn|PgUp|
+--+----+---+---+---+---+----+----+----+----+----+-----+---+----+----+----+----+
|Ax|    |   |   |   |   |    |    |    |    |    |     |   |    |    |    |    |
+--+----+---+---+---+---+----+----+----+----+----+-----+---+----+----+----+----+
|Bx|    |   |   |   |   |    |    |    |    |    |     |   |    |    |    |    |
+--+----+---+---+---+---+----+----+----+----+----+-----+---+----+----+----+----+
|Cx|    |App|Num|Scr|   |NoCv|Conv|Kana|Home|    | F10 |F11|F12 |Ins |    |    |
+--+----+---+---+---+---+----+----+----+----+----+-----+---+----+----+----+----+
|Dx|    |   |   |   |   |    |    |    |    |    |     |   |    |    |    |    |
+--+----+---+---+---+---+----+----+----+----+----+-----+---+----+----+----+----+
|Ex|KRet|   |   |K# |   |    |    |    |    |    |  K* |K+ | K, | K- | K. | K/ |
+--+----+---+---+---+---+----+----+----+----+----+-----+---+----+----+----+----+
|Fx| K0 |K1 |K2 |K3 |K4 | K5 | K6 | K7 | K8 | K9 |     |   |    | K= |    |DEL |
+--+----+---+---+---+---+----+----+----+----+----+-----+---+----+----+----+----+

&80-&DF modified with Shift/Ctrl/Alt. &E0-&FF added to keypad base, &E0 translated
to &CD for keypad 13, &FF translated to &3F for DELETE.


References:
 web.archive.org/web/20130401185753/http://www.iyonix.com/32bit/2205203-02.htm
 www.riscosopen.org/wiki/documentation/show/Character%20Codes
 www.riscosopen.org/wiki/documentation/show/OS_Byte%20221%20-%20228%20Key%20Codes