Spectrum Keyboard
                              =================
                            Low level key numbers

     +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
A11--| &24 | &1C | &14 | &0C | &04 | &03 | &0B | &13 | &1B | &23 |      --A12
     |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  8  |  9  |  0  |
     +-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+
A10--  | &25 | &1D | &15 | &0D | &05 | &02 | &0A | &12 | &1A | &22 |    --A13
       |  Q  |  W  |  E  |  R  |  T  |  Y  |  U  |  I  |  O  |  P  |
       +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
A9--      | &26 | &1E | &16 | &0E | &06 | &01 | &09 | &11 | &19 | &21 | --A14
          |  A  |  S  |  D  |  F  |  G  |  H  |  J  |  K  |  L  |ENTER|
     +----+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+-----+
A8-- |  &27   | &1F | &17 | &0F | &07 | &00 | &08 | &10 | &18 |  &20  | --A15
     | SHIFT  |  Z  |  X  |  C  |  V  |  B  |  N  |  M  | SYM | SPACE |
     +--------+-----+-----+-----+-----+-----+-----+-----+-----+-------+
         |       |     |     |     |     |     |     |     |      |
         D0      D1    D2    D3    D4    D4    D3    D2    D1     D0


 D4 D3 D2 D1 D0 A15 A14 A13 A12 A11 A10 A9 A8
  \----\ /---/   \------------\ /----------/
       0-4                    0-7
        +------+       +-------+
               |       |
          +--+--+--+--+--+--+
          |  :  :  |  :  :  |
          +--+--+--+--+--+--+