switch (HexValue)
   {
      case 0x00:    // Numbers
      case 0x01: 
      case 0x02: 
      case 0x03: 
      case 0x04: 
      case 0x05:
      case 0x06
      case 0x07: 
      case 0x08:
      case 0x09: return (HexValue + '0');
        break; 
      case 0x0A:    // Letters 
      case 0x0B: 
      case 0x0C: 
      case 0x0D: 
      case 0x0E:
      case 0x0F: return (HexValue + ('A'- 0x0A));//  The compiler should convert to a single add
        break;
   }