How to Make PS2 Keyboard Read Display system Based on Arduin

How to Make PS2 Keyboard Read Display system Based on Arduino by ICStation(www.ICStation.com)
http://www.instructables.com/id/How-to-Make-PS2-Keyboard-Read-Display-system-Based/

Code for reference:
#include <LiquidCrystal.h>
#define uchar unsigned char
#define uint unsigned int
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
uchar  KB_CLK=8;
uchar  KB_DATA=9;
uint n=0;
uchar Key_Code1;
void setup()
{
  lcd.begin(16, 2);
  pinMode(KB_CLK,INPUT);
  pinMode(KB_DATA,INPUT);
  Key_Code1=0;
  lcd.setCursor(3,0);
  lcd.print("ICStation");
  lcd.setCursor(3,1);
  lcd.print("PS2:");
}

void loop()
{
   Key_Code1=Get_Key();
  if(Key_Code1!=0x00)
  {
    lcd.setCursor(7,1);
    lcd.write(Key_Code1);
  }
}
/*********************************************************************
funcname： Key_Scan(void)
functional description： Read the PS2 keyboard to send data
suction parameter： not have
outlet parameters： Function returns the value of key_temp
**********************************************************************/
uchar Key_Scan(void)
{
  uchar i,key_temp;
  digitalWrite(KB_CLK,HIGH);        //import
  digitalWrite(KB_DATA,HIGH);
  key_temp=0;

  while(digitalRead(KB_CLK));     //The first is 0 (low level start reading)
  for (i = 0; i < 8; ++i)
      {
          while(!digitalRead(KB_CLK));
          while(digitalRead(KB_CLK));
          key_temp |= digitalRead(KB_DATA) << i;
      }
  while(!digitalRead(KB_CLK));   //parity bit
  while(digitalRead(KB_CLK));    //Remove efficacy bit and stop bit
  while(!digitalRead(KB_CLK));   //stop bit
  while(digitalRead(KB_CLK));
  while(!digitalRead(KB_CLK));
  return key_temp;
}
/*********************************************************************
funcname： uchar Get_Key(void)
functional description： PS2 keyboard characters will be sent to show the data you sent
suction parameter： Key_Code
outlet parameters： 无
********************************************************************/
uchar Get_Key(void)
{
  uchar Key_Code,Key_Code2;
  Key_Code2=Key_Scan();
  Key_Code=Key_Scan();
  if(Key_Code2==0x12)
  {
    Key_Code=Key_Scan();
      switch(Key_Code)
		{
		   case 0x1c: return 'A';break;
		   case 0x32: return 'B';break;
		   case 0x21: return 'C';break;
		   case 0x23: return 'D';break;
		   case 0x24: return 'E';break;
		   case 0x2b: return 'F';break;
		   case 0x34: return 'G';break;
		   case 0x33: return 'H';break;
		   case 0x43: return 'I';break;
		   case 0x3b: return 'J';break;
		   case 0x42: return 'K';break;
		   case 0x4b: return 'L';break;
		   case 0x3a: return 'M';break;
		   case 0x31: return 'N';break;
		   case 0x44: return 'O';break;
		   case 0x4d: return 'P';break;
		   case 0x15: return 'Q';break;
		   case 0x2d: return 'R';break;
		   case 0x1b: return 'S';break;
		   case 0x2c: return 'T';break;
		   case 0x3c: return 'U';break;
		   case 0x2a: return 'V';break;
		   case 0x1d: return 'W';break;
		   case 0x22: return 'X';break;
		   case 0x35: return 'Y';break;
		   case 0x1a: return 'Z';break;
		   case 0x45: return ')';break;//The number keys
		   case 0x16: return '!';break;
		   case 0x1e: return '@';break;
		   case 0x26: return '#';break;
		   case 0x25: return '$';break;
		   case 0x2e: return '%';break;
		   case 0x36: return '^';break;
		   case 0x3d: return '&';break;
		   case 0x3e: return '*';break;
		   case 0x46: return '(';break;
		   default: return 0x00; break;
    }
  }
  else
      switch(Key_Code)
      {
                   case 0x1c: return 'a';break;
  		   case 0x32: return 'b';break;
  		   case 0x21: return 'c';break;
  		   case 0x23: return 'd';break;
  		   case 0x24: return 'e';break;
  		   case 0x2b: return 'f';break;
  		   case 0x34: return 'g';break;
  		   case 0x33: return 'h';break;
  		   case 0x43: return 'i';break;
  		   case 0x3b: return 'j';break;
  		   case 0x42: return 'k';break;
  		   case 0x4b: return 'l';break;
  		   case 0x3a: return 'm';break;
  		   case 0x31: return 'n';break;
  		   case 0x44: return 'o';break;
  		   case 0x4d: return 'p';break;
  		   case 0x15: return 'q';break;
  		   case 0x2d: return 'r';break;
  		   case 0x1b: return 's';break;
  		   case 0x2c: return 't';break;
  		   case 0x3c: return 'u';break;
  		   case 0x2a: return 'v';break;
  		   case 0x1d: return 'w';break;
  		   case 0x22: return 'x';break;
  		   case 0x35: return 'y';break;
  		   case 0x1a: return 'z';break;
  		   case 0x45: return '0';break;//The number keys
  		   case 0x16: return '1';break;
  		   case 0x1e: return '2';break;
  		   case 0x26: return '3';break;
  		   case 0x25: return '4';break;
  		   case 0x2e: return '5';break;
  		   case 0x36: return '6';break;
  		   case 0x3d: return '7';break;
  		   case 0x3e: return '8';break;
  		   case 0x46: return '9';break;
  		   default: return 0x00; break;
    }
}
void Delay_NS(int x)
{
for(;x>0;x--);
}