Acorn/RISC OS Keymapping with Windows keyboard
                  ==============================================

+==+=====+=====+===+===+===+===+===+===+===+===+======+====+====+====+=====+=====+
|  | x0  | x1  | x2| x3| x4| x5| x6| x7| x8| x9|  xA  | xB | xC | xD | xE  | xF  |
+==+=====+=====+===+===+===+===+===+===+===+===+======+====+====+====+=====+=====+
|0x|     |     |   |   |   |   |   |   |BS |Tab|      |    |    |Retn|     |     |
+--+-----+-----+---+---+---+---+---+---+---+---+------+----+----+----+-----+-----+
|1x|     |     |   |   |   |   |   |   |   |   |      | Esc|    |    |Home |     |
+--+-----+-----+---+---+---+---+---+---+---+---+------+----+----+----+-----+-----+
+--+-----+-----+---+---+---+---+---+---+---+---+------+----+----+----+-----+-----+
|7x|     |     |   |   |   |   |   |   |   |   |      |    |    |    |     | Del |
+--+-----+-----+---+---+---+---+---+---+---+---+------+----+----+----+-----+-----+
|8x|  F0 |  F1 | F2| F3| F4| F5| F6| F7| F8| F9| Break| End|  <-|  ->| Dn  | Up  |
|  | Prnt|     |   |   |   |   |   |   |   |   |  Tab |    |    |    |sPgDn|sPgUp|
+--+-----+-----+---+---+---+---+---+---+---+---+------+----+----+----+-----+-----+
|9x| sF0 | sF1 |sF2|sF3|sF4|sF5|sF6|sF7|sF8|sF9|sBreak|sEnd| s<-| s->| sDn | sUp |
|  |sPrnt|     |   |   |   |   |   |   |   |   | sTab |    |    |    |PgDn |PgUp |
+--+-----+-----+---+---+---+---+---+---+---+---+------+----+----+----+-----+-----+
|Ax| cF0 | cF1 |cF2|cF3|cF4|cF5|cF6|cF7|cF8|cF9|cBreak|cEnd| c<-| c->| cDn | cUp |
|  |cPrnt|     |   |   |   |   |   |   |   |   | cTab |    |    |    |aPgDn|aPgUp|
+--+-----+-----+---+---+---+---+---+---+---+---+------+----+----+----+-----+-----+
|Bx| aF0 | aF1 |aF2|aF3|aF4|aF5|aF6|aF7|aF8|aF9|aBreak|aEnd| a<-| a->| aDn | aUp |
|  |aPrnt|     |   |   |   |   |   |   |   |   | aTab |    |    |    |cPgDn|cPgUp|
+--+-----+-----+---+---+---+---+---+---+---+---+------+----+----+----+-----+-----+
|Cx| LWin| Menu|   |   |   |   |   |   |   |   |  F10 | F11| F12| Ins| MsDn| MsUp|
|  |sRWin|     |   |   |   |   |   |   |   |   |      |    |    |    |     |     |
+--+-----+-----+---+---+---+---+---+---+---+---+------+----+----+----+-----+-----+
|Dx|sLWin|sMenu|   |   |   |   |   |   |   |   | sF10 |sF11|sF12|sIns|sMsDn|sMsUp|
|  | RWin|     |   |   |   |   |   |   |   |   |      |    |    |    |     |     |
+--+-----+-----+---+---+---+---+---+---+---+---+------+----+----+----+-----+-----+
|Ex|cLWin|cMenu|   |   |   |   |   |   |   |   | cF10 |cF11|cF12|cIns|cMsDn|cMsUp|
|  |aRWin|     |   |   |   |   |   |   |   |   |      |    |    |    |     |     |
+--+-----+-----+---+---+---+---+---+---+---+---+------+----+----+----+-----+-----+
|Fx|aLWin|aMenu|   |   |   |   |   |   |   |   | aF10 |aF11|aF12|aIns|aMsDn|aMsUp|
|  |cRWin|     |   |   |   |   |   |   |   |   |      |    |    |    |     |     |
+--+-----+-----+---+---+---+---+---+---+---+---+------+----+----+----+-----+-----+

Within the desktop TAB is programmed to be soft key 10 and BREAK does Break/Reset
actions. In Wimp Messages special keypresses are ORed with &100 to distinguish them
from top-bit-set characters.