Port B - $DC01
              +-----+-----+-----+-----+-----+-----+-----+-----+
              |Bit 0|Bit 1|Bit 2|Bit 3|Bit 4|Bit 5|Bit 6|Bit 7|
        +-----+-----+-----+-----+-----+-----+-----+-----+-----+
        |Bit 0| DEL |  CR |C_L/R|  F7 |  F1 |  F3 |  F5 |C_U/D|
        +-----+-----+-----+-----+-----+-----+-----+-----+-----+
        |Bit 1|  3  |  W  |  A  |  4  |  Z  |  S  |  E  | S_L |
        +-----+-----+-----+-----+-----+-----+-----+-----+-----+
        |Bit 2|  5  |  R  |  D  |  6  |  C  |  F  |  T  |  X  |
 Port A +-----+-----+-----+-----+-----+-----+-----+-----+-----+
 $DC00  |Bit 3|  7  |  Y  |  G  |  8  |  B  |  H  |  U  |  V  |
        +-----+-----+-----+-----+-----+-----+-----+-----+-----+
        |Bit 4|  9  |  I  |  J  |  0  |  M  |  K  |  O  |  N  |
        +-----+-----+-----+-----+-----+-----+-----+-----+-----+
        |Bit 5|  +  |  P  |  L  |  -  |  .  |  :  |  @  |  ,  |
        +-----+-----+-----+-----+-----+-----+-----+-----+-----+
        |Bit 6|  œ  |  *  |  ;  | HOME| S_R |  =  | A_UP|  /  |
        +-----+-----+-----+-----+-----+-----+-----+-----+-----+
        |Bit 7|  1  |A_LFT| CTRL|  2  |SPACE|  C= |  Q  | R/S |
        +-----+-----+-----+-----+-----+-----+-----+-----+-----+

  C_L/R = Cursor left/right  ;  C_U/D = Cursor up/down
  S_L = Left Shift  ;  S_R = Right Shift  ;  R/S = RUN/STOP
  A_UP = Arrow up   ;  A_LFT = Arrow left

 C128 only:
                               Port B - $DC01
              +-----+-----+-----+-----+-----+-----+-----+-----+
              |Bit 0|Bit 1|Bit 2|Bit 3|Bit 4|Bit 5|Bit 6|Bit 7|
        +-----+-----+-----+-----+-----+-----+-----+-----+-----+
        |Bit 0| HELP| "8" | "5" | TAB | "2" | "4" | "7" | "1" |
 Port A*+-----+-----+-----+-----+-----+-----+-----+-----+-----+
 $D02F  |Bit 1| ESC | "+" | "-" |  LF | "CR"| "6" | "9" | "3" |
        +-----+-----+-----+-----+-----+-----+-----+-----+-----+
        |Bit 2| ALT | "0" | "." | 'U' | 'D' | 'L' | 'R' |NOSCR|
        +-----+-----+-----+-----+-----+-----+-----+-----+-----+

  "x" = means key is on the keypad to the right
  'x' = means grey cursor-control key at the upper side
        (U/D/L/R = up/down/left/right)