The following table represents the ASCII character set (characters
  with decimal values 0 through 127).  Except for SP and HT, the
  characters with names are nonprintable.

  To determine the hexadecimal value of an ASCII character, combine
  the values in the column (0-7) and the row (0-F) that relate to the
  character.  For example, the value of the character representing
  the equal sign is 3D(hex).

    +------------------------------------------+
    |     0     1     2    3   4   5   6   7   |
    +---+--------------------------------------+
    | 0 | NUL   DLE   SP   0   @   P   `   p   |
    | 1 | SOH   DC1   !    1   A   Q   a   q   |
    | 2 | STX   DC2   "    2   B   R   b   r   |
    | 3 | ETX   DC3   #    3   C   S   c   s   |
    | 4 | EOT   DC4   $    4   D   T   d   t   |
    | 5 | ENQ   NAK   %    5   E   U   e   u   |
    | 6 | ACK   SYN   &    6   F   V   f   v   |
    | 7 | BEL   ETB   '    7   G   W   g   w   |
    | 8 | BS    CAN   (    8   H   X   h   x   |
    | 9 | HT    EM    )    9   I   Y   i   y   |
    | A | LF    SUB   *    :   J   Z   j   z   |
    | B | VT    ESC   +    ;   K   [   k   {   |
    | C | FF    FS    ,    <   L   \   l   |   |
    | D | CR    GS    -    =   M   ]   m   }   |
    | E | SO    RS    .    >   N   ^   n   ~   |
    | F | SI    US    /    ?   O   _   o   DEL |
    +---+--------------------------------------+

  The characters with names are defined as follows:

    NUL   Null             DC1   Device Control 1(XON)
    SOH   Start of         DC2   Device Control 2
            Heading
    STX   Start of Text    DC3   Device Control 3(XOFF)
    ETX   End of Text      DC4   Device Control 4
    EOT   End of           NAK   Negative Acknowledge
            Transmission
    ENQ   Enquiry          SYN   Synchronous Idle
    ACK   Acknowledge      ETB   End of Transmission
                                   Block
    BEL   Bell             CAN   Cancel
    BS    Backspace        EM    End of Medium
    HT    Horizontal Tab   SUB   Substitute
    LF    Line Feed        ESC   Escape
    VT    Vertical Tab     FS    File Separator
    FF    Form Feed        GS    Group Separator
    CR    Carriage Return  RS    Record Separator
    SO    Shift Out        US    Unit Separator
    SI    Shift In         SP    Space
    DLE   Data Link        DEL   Delete
            Escape