*FX254,128 is set by default to set the keyboard map to match the OSBYTE 0 value.
*FX254,192 forces the keymap to match the RISC OS keyboard map.


RISC OS Keymap - OSBYTE 0 = %000x0xxx, Acorn hardware/MOS or forced with *FX254,192 (b6=1)
==========================================================================================

+===+======+======+=====+=====+=====+=====+=====+=====+======+=====+=======+=====+=====+=====+======+======+
|   |   0  |   1  |  2  |  3  |  4  |  5  |  6  |  7  |   8  |  9  |   A   |  B  |  C  |  D  |   E  |   F  |
+===+======+======+=====+=====+=====+=====+=====+=====+======+=====+=======+=====+=====+=====+======+======+
|00x|      |      |     |     |     |     |     |     |  BS  | Tab |       |     |     |Retrn|      |      |
+---+------+------+-----+-----+-----+-----+-----+-----+------+-----+-------+-----+-----+-----+------+------+
|01x|      |      |     |     |     |     |     |     |      |     |       | Esc |     |     | Home |      |
+---+------+------+-----+-----+-----+-----+-----+-----+------+-----+-------+-----+-----+-----+------+------+
+---+------+------+-----+-----+-----+-----+-----+-----+------+-----+-------+-----+-----+-----+------+------+
|07x|      |      |     |     |     |     |     |     |      |     |       |     |     |     |      |  Del |
+---+------+------+-----+-----+-----+-----+-----+-----+------+-----+-------+-----+-----+-----+------+------+
|18x|  F0  |  F1  | F2  | F3  | F4  | F5  | F6  | F7  |  F8  | F9  |  Tab  | End | <-  | ->  |  Dn  |  Up  |
|   | Prnt |      |     |     |     |     |     |     |      |     | Break |     |     |     | sPgDn| sPgUp|
+---+------+------+-----+-----+-----+-----+-----+-----+------+-----+-------+-----+-----+-----+------+------+
|19x| sF0  |  sF1 | sF2 | sF3 | sF4 | sF5 | sF6 | sF7 |  sF8 | sF9 |  sTab | sEnd| s<- | s-> |  sDn | sUp  |
|   |sPrnt |      |     |     |     |     |     |     |      |     | sBreak|     |     |     | PgDn | PgUp |
+---+------+------+-----+-----+-----+-----+-----+-----+------+-----+-------+-----+-----+-----+------+------+
|1Ax| cF0  |  cF1 | cF2 | cF3 | cF4 | cF5 | cF6 | cF7 |  cF8 | cF9 |  cTab | cEnd| c<- | c-> |  cDn | cUp  |
|   |cPrnt |      |     |     |     |     |     |     |      |     | cBreak|     |     |     |scPgDn|scPgUp|
+---+------+------+-----+-----+-----+-----+-----+-----+------+-----+-------+-----+-----+-----+------+------+
|1Bx| scF0 | scF1 |scF2 |scF3 |scF4 |scF5 |scF6 |scF7 | scF8 |scF9 | scTab |scEnd|sc<- |sc-> | scDn | scUp |
|   |scPrnt|      |     |     |     |     |     |     |      |     |scBreak|     |     |     | cPgDn| cPgUp|
+---+------+------+-----+-----+-----+-----+-----+-----+------+-----+-------+-----+-----+-----+------+------+
|1Cx|  LWin| Menu |     |     |     |     |     |     |      |     |  F10  | F11 | F12 | Ins | MsDn | MsUp |
|   | sRWin|      |     |     |     |     |     |     |      |     |       |     |     |     |      |      |
+---+------+------+-----+-----+-----+-----+-----+-----+------+-----+-------+-----+-----+-----+------+------+
|1Dx| sLWin| sMenu|     |     |     |     |     |     |      |     |  sF10 | sF11| sF12| sIns|sMsDn |sMsUp |
|   |  RWin|      |     |     |     |     |     |     |      |     |       |     |     |     |      |      |
+---+------+------+-----+-----+-----+-----+-----+-----+------+-----+-------+-----+-----+-----+------+------+
|1Ex| cLWin| cMenu|     |     |     |     |     |     |      |     |  cF10 | cF11| cF12| cIns|cMsDn |cMsUp |
|   |scRWin|      |     |     |     |     |     |     |      |     |       |     |     |     |      |      |
+---+------+------+-----+-----+-----+-----+-----+-----+------+-----+-------+-----+-----+-----+------+------+
|1Fx|scLWin|scMenu|     |     |     |     |     |     |      |     | scF10 |scF11|scF12|scIns|scMsDn|scMsUp|
|   | cRWin|      |     |     |     |     |     |     |      |     |       |     |     |     |      |      |
+---+------+------+-----+-----+-----+-----+-----+-----+------+-----+-------+-----+-----+-----+------+------+


Regular Keymap - OSBYTE 0 <>%000x0xxx, non-Acorn hardware default with *FX254,128 (b6=0)
========================================================================================

+===+=====+=====+===+===+===+===+====+====+=====+====+======+=====+====+====+=====+=====+
|   |  0  |  1  | 2 | 3 | 4 | 5 |  6 |  7 |  8  |  9 |   A  |  B  |  C |  D |  E  |  F  |
+===+=====+=====+===+===+===+===+====+====+=====+====+======+=====+====+====+=====+=====+
|00x|     |     |   |   |   |   |    |    |  BS | Tab|      |     |    | Ret|     |     |
+---+-----+-----+---+---+---+---+----+----+-----+----+------+-----+----+----+-----+-----+
|01x|     |     |   |   |   |   |    |    |     |    |      | Esc |    |    |     |     |
+---+-----+-----+---+---+---+---+----+----+-----+----+------+-----+----+----+-----+-----+
+---+-----+-----+---+---+---+---+----+----+-----+----+------+-----+----+----+-----+-----+
|07x|     |     |   |   |   |   |    |    |     |    |      |     |    |    |     | Del |
+---+-----+-----+---+---+---+---+----+----+-----+----+------+-----+----+----+-----+-----+
|18x| Prnt|  F1 | F2| F3| F4| F5| F6 | F7 |  F8 | F9 | F10  | F11 | F12| F13| F14 | F15 |
+---+-----+-----+---+---+---+---+----+----+-----+----+------+-----+----+----+-----+-----+
|19x|sPrnt| sF1 |sF2|sF3|sF4|sF5| sF6| sF7| sF8 | sF9| sF10 | sF11|sF12|sF13|sF14 |sF15 |
+---+-----+-----+---+---+---+---+----+----+-----+----+------+-----+----+----+-----+-----+
|1Ax|cPrnt| cF1 |cF2|cF3|cF4|cF5| cF6| cF7| cF8 | cF9| cF10 | cF11|cF12|cF13|cF14 |cF15 |
+---+-----+-----+---+---+---+---+----+----+-----+----+------+-----+----+----+-----+-----+
|1Bx|aPrnt| aF1 |aF2|aF3|aF4|aF5| aF6| aF7| aF8 | aF9| aF10 | aF11|aF12|aF13|aF14 |aF15 |
+---+-----+-----+---+---+---+---+----+----+-----+----+------+-----+----+----+-----+-----+
|1Cx| Win | Menu|   |   |   |   | Ins| Del| Home| End| PgDn | PgUp| <- | -> | Dn  | Up  |
+---+-----+-----+---+---+---+---+----+----+-----+----+------+-----+----+----+-----+-----+
|1Dx|sWin |sMenu|   |   |   |   |sIns|sDel|sHome|sEnd|sPgDn |sPgUp| s<-| s->| sDn | sUp |
+---+-----+-----+---+---+---+---+----+----+-----+----+------+-----+----+----+-----+-----+
|1Ex|cWin |cMenu|   |   |   |   |cIns|cDel|cHome|cEnd|cPgDn |cPgUp| c<-| c->| cDn | cUp |
+---+-----+-----+---+---+---+---+----+----+-----+----+------+-----+----+----+-----+-----+
|1Fx|aWin |aMenu|   |   |   |   |aIns|aDel|aHome|aEnd|aPgDn |aPgUp| a<-| a->| aDn | aUp |
+---+-----+-----+---+---+---+---+----+----+-----+----+------+-----+----+----+-----+-----+