Hi, i am doing a logic game and i must allow control via buttons on PORT1 and via RS232 (terminal)
Here is my code, which i wrote.. its using GLCD 128x64

#include <reg51.h>
#include <intrins.h>
#include <stdio.h>
typedef unsigned char byte;
typedef unsigned int word;

sbit GRST = P2^5;
sbit GE = P2^4;
sbit GRW = P2^3;
sbit GRS = P2^2;
sbit GCS2 = P2^1;
sbit GCS1 = P2^0;

#define GDATA P0

void signal_init(void)
{
  GRST = 1;

  GCS1 = 0;
  GCS2 = 0;
  GDATA = 0;
  GRW = 0;
  GE = 0;
  GRS = 0;
}

void wait_reset(bit controller)
{
  byte b = 0;

  GCS1 = controller;
  GCS2 = ~controller;

  GDATA = 0xff;
  GRS = 0;
  GRW = 1;
  do
  {
    GE = 1;
    _nop_();
    _nop_();
    _nop_();

    b = GDATA;
    GE = 0;
  } while (b & 0x10);

  return;
}

void wait_busy(bit controller)
{
  byte b = 0;

  GCS1 = controller;
  GCS2 = ~controller;

  GDATA = 0xff;
  GRS = 0;
  GRW = 1;
  do
  {
    GE = 1;
    _nop_();
    _nop_();
    _nop_();

    b = GDATA;
    GE = 0;
  } while (b & 0x80);

  return;
}

void write_cmnd(byte g_cmnd, bit controller)
{
  GCS1 = controller;
  GCS2 = ~controller;

  GRS = 0;
  GRW = 0;
  GDATA = g_cmnd;
  GE = 1;
  _nop_();
  _nop_();
  GE = 0;

  return;
}

void write_data(byte g_data, bit controller)
{
  GCS1 = controller;
  GCS2 = ~controller;

  GRS = 1;
  GRW = 0;
  GDATA = g_data;
  GE = 1;
  _nop_();
  _nop_();
  GE = 0;

  return;
}

byte cekej100 = 0;

void timer0(void) interrupt 1
{
  if (cekej100 > 0)
    cekej100--;
}


#define WAIT(doba) {cekej100 = doba; while (cekej100) ;}

#define SET_G_PAGE(page, radic) {write_cmnd(0xb8 + page, radic); wait_busy(radic); }
#define SET_G_YADR(addr, radic) {write_cmnd(0x40 + addr, radic); wait_busy(radic); }
///Funct for wirite nums and letters to GLCD - OK
void write_num(char num,byte strana)
{
byte i;
  char chars[]=
	{
	0x3e,0x51,0x49,0x45,0x3e, /* 0		0x30 */
	0x00,0x42,0x7f,0x40,0x00, /* 1 */
	0x42,0x61,0x51,0x49,0x46, /* 2 */	
	0x21,0x41,0x45,0x4b,0x31, /* 3 */
	0x18,0x14,0x12,0x7f,0x10, /* 4 */
	0x27,0x45,0x45,0x45,0x39, /* 5 */
	0x3c,0x4a,0x49,0x49,0x30, /* 6 */
  	//0x00,0x00,0x77,0x00,0x00, /* | */
  	0x00,0x00,0x4f,0x00,0x00, /* ! */
  	0x3e,0x41,0x41,0x41,0x3e, /* O */
	//0x7f,0x08,0x14,0x22,0x41 /* K */
	};
for (i=num*5;i<num*5+5;i++)
{
write_data(chars[i], strana);
}
}
//Blink on actual position - OK
void blink(int x,int actual_page,int num,strana)
{
int i;
   SET_G_PAGE(actual_page, strana); SET_G_YADR(x*8, strana); 
        for(i = 0; i < 8; i++)
          {
          write_data(0, 0);
          wait_busy(0);
          }
        for (i=0;i<10000;i++) _nop_();
        SET_G_PAGE(actual_page, strana); SET_G_YADR(x*8, strana); 
        
        write_num(num,strana);
        wait_busy(0);
        for (i=0;i<10000;i++) _nop_();
        
}
//delete GLCD - OK
void smazat()
{
byte p,x;
 			///smazat
  for (p = 0; p < 8; p++)
  {
    SET_G_PAGE(p, 0);
    SET_G_YADR(0, 0);
    for(x = 0; x < 64; x++)
    {
      write_data(0, 0);
      wait_busy(0);
    }
    SET_G_PAGE(p, 1);
    SET_G_YADR(0, 1);

    for(x = 0; x < 64; x++)
    {
      write_data(0, 1);
      wait_busy(1);
    } 
  }
}


int main(void)
{
  byte actual_x=0; //
  byte actual_page=1;  //souradnice y disp
  byte pole[8]; //Save user input into array
  byte polerand[8]; //Array with opponents data
  byte zad=0; 
  byte x = 0; //for for
  byte pom=0; //
  byte aa=0;  //num of  trays
  byte pocet=6; //num of combinations allowed
  unsigned char c; //should be for terminal later

  for (x=0;x<8;x++) {pole[x]=0;} //delete array
    
  signal_init();

  //P3 = ~(++u);
  //Set timer+interrupts
  TMOD = 0x22;
  TH0 = 256 - 100;
  TR0 = 1;
  ET0 = 1;
  EA = 1;
  //Set Serial
  TH1 = 0xEF; // pro rychlost 1200/2400 Bd pri 8MHz krystalu
  TR1 = 1; // start citace
  SCON = 0x52; // standardni nastaveni serioveho kanalu
  PCON |= 0x80; // SMOD=1 => zdvojeni seriove rychlosti (na 24
  ES=1; 
  //inicializace LCD
  GRST = 1;
  WAIT(250);
  GRST = 0;
  WAIT(250);
  GRST = 1;
  WAIT(250);
  wait_reset(0);
  wait_reset(1);
  write_cmnd(0x3f, 0);
  wait_busy(0);
  write_cmnd(0x3f, 1);
  wait_busy(1);
  //vymazani LCD
  smazat();
  SET_G_PAGE(0, 0);
  SET_G_YADR(0, 0);
  //Display Z - zadavani
  //0x61,0x51,0x49,0x45,0x43, /* Z */
  write_data(0x61,0);
  write_data(0x51,0);
  write_data(0x49,0);
  write_data(0x45,0);
  write_data(0x43,0);
  ////////////////////////
  //puts("nZadavanin");
  while(1)
  {
  /////
  blink(actual_x,actual_page,pole[actual_x],0);  //blink on actual position
 
 if (P1==0xfe) //press button - left
      {
      if (pom==0)
	  {
        pom=1;
        if (actual_x==7) actual_x=-1; //if we are on end...
        actual_x++;     
        SET_G_PAGE(actual_page, 0); SET_G_YADR(actual_x*8, 0); 	//set GLCD to actual position
        for(x = 0; x < 8; x++) //delete actual num at first
          {
          write_data(0, 0);
          wait_busy(0);
          }
        SET_G_PAGE(actual_page, 0); SET_G_YADR(actual_x*8, 0); 	 //Print num from array to disp
        if (pole[actual_x]==0) {pole[actual_x]=1; }
        write_num(pole[actual_x],0);
        wait_busy(0);
        WAIT(100000000);
       }

    }
    if (P1==0xff) WAIT(100000000); pom=0;
  	if (P1==0xfd)
	{	//button num 2 - same as before, but to right
  		if (pom==0){
     	pom=1;
     		
        	if (actual_x==0) actual_x=8;
        	actual_x--;

        	SET_G_PAGE(actual_page, 0); SET_G_YADR(actual_x*8, 0); 
        	for(x = 0; x < 8; x++)
          		{
          		write_data(0, 0);
          		wait_busy(0);
          		}
        	SET_G_PAGE(actual_page, 0); SET_G_YADR(actual_x*8, 0); 
        	if (pole[actual_x]==0) {pole[actual_x]=1; }
        	write_num(pole[actual_x],0);
        	wait_busy(0);
        	WAIT(100000000);            
     	}
	 }
  if (P1==0xfb){ //change num - button num 3
  if (pom==0){
     pom=1;
     
        SET_G_PAGE(actual_page, 0); SET_G_YADR(actual_x*8, 0); 
        for(x = 0; x < 8; x++)
          {
          write_data(0, 0);
          wait_busy(0);
          }
        SET_G_PAGE(actual_page, 0); SET_G_YADR(actual_x*8, 0); 

        pole[actual_x]++;			//increase num in array
        if (pole[actual_x]>=pocet) pole[actual_x]=1;   //was max num?
        write_num(pole[actual_x],0);		 //print to GLCD
        
        wait_busy(0);
        WAIT(100000000);
      }      
     }
     if (P1==0xf7){   //ENTER - button num. 4
  	 if (pom==0){
     pom=1;   
	 if (zad==1) //opponent already type their combination
     {
      byte actual_x_v=0;
      byte xx;
      byte polepom[8];
      SET_G_PAGE(actual_page, 1); SET_G_YADR(actual_x_v*8, 1); //print "|"
      //write_num(7,1);
      //0x00,0x00,0x77,0x00,0x00  | //print |
      write_data(0x00,1);
      write_data(0x00,1);
      write_data(0x77,1);
      write_data(0x00,1);
      write_data(0x00,1);
      wait_busy(0);
      actual_x_v++;	  //position on GLCD
      
      for (x=0;x<8;x++) { polepom[x]=0;} //delete "help" array
      for (x=0;x<8;x++) { 	  //test if user input is same as type opponent on start
        if (pole[x]==polerand[x])
        {
              polepom[x]=1;
              SET_G_PAGE(actual_page, 1); SET_G_YADR(actual_x_v*8, 1); 
              write_num(7,1); //
              wait_busy(0);
              actual_x_v++;
	      aa++;   //count num of OK
        }  
      }
      for (x=0;x<8;x++) //Test good nums, but on wrong position
      {
        for (xx=0;xx<8;xx++)
        {
          if ((polerand[xx]==pole[x])&&(polepom[x]==0))
          {
              SET_G_PAGE(actual_page, 1); SET_G_YADR(actual_x_v*8, 1); 
              write_num(8,1);
              wait_busy(0);
              actual_x_v++;
              polepom[x]=2;

          }
        }
      }
      //SET_G_PAGE(actual_page, 1); SET_G_YADR(actual_x_v*8, 1); 
      actual_page++;
      actual_x=0; 
	if (aa==8) //All was OK
	{
		smazat();
		actual_x=0;
		actual_page=0; 

		//0x3e,0x41,0x41,0x41,0x3e, /* O */
		//0x7f,0x08,0x14,0x22,0x41 /* K */
  		SET_G_PAGE(2, 0); SET_G_YADR(10, 0); //print OK
  		write_data(0x3e,0);
		wait_busy(0);
  		write_data(0x41,0);
		wait_busy(0);
  		write_data(0x41,0);
		wait_busy(0);
  		write_data(0x41,0);
		wait_busy(0);
  		write_data(0x3e,0);
  		SET_G_YADR(18, 0);
  		write_data(0x7f,0);
		wait_busy(0);
  		write_data(0x08,0);
		wait_busy(0);
  		write_data(0x14,0);
		wait_busy(0);
  		write_data(0x22,0);
		wait_busy(0);
  		write_data(0x41,0);
  		wait_busy(0);
	}
	if (actual_page==8)//try 8x and was wrong
	{
		smazat();
		actual_x=0;
		actual_page=0; 

  		SET_G_PAGE(2, 0); SET_G_YADR(10, 0); //print KO
		wait_busy(0);
    	write_data(0x7f,0);
		wait_busy(0);
  		write_data(0x08,0);
		wait_busy(0);
  		write_data(0x14,0);
		wait_busy(0);
  		write_data(0x22,0);
		wait_busy(0);
  		write_data(0x41,0);
		wait_busy(0);
  		SET_G_YADR(18, 0);
		wait_busy(0);
  		write_data(0x3e,0);
		wait_busy(0);
  		write_data(0x41,0);
		wait_busy(0);
  		write_data(0x41,0);
		wait_busy(0);
  		write_data(0x41,0);
		wait_busy(0);
  		write_data(0x3e,0);

	
	}
        
      }
	  else //save opponent combination
	  {
	  zad=1;
	  for (x=0;x<8;x++)
	  	{
			polerand[x]=pole[x]; //presuneme vsechno z pole do polerand a pole nulujeme
			pole[x]=0;
		}
		smazat();		 //smazeme disp
	    actual_x=0;
	  	actual_page=0; 
	
	  }
	  wait_busy(0);      
     }}

    
}    
}



 

I am not sure howto optimize it, i am new in programming for 8052. I can now type combination via buttons on gate P1 soso :) But i need also type it via terminal (RS232). I am not sure, howto do it. I will probably need to use interrupt from serial? Can someone help me with this code please? Thank You very much