RS232 LCD Terminal w/ EEPROM access

#include <main.h>
#include <flex_lcd.c>

// Ad hoc programming, only for testing purpose (demo).
// Needs to be revised before using.

#INT_EXT
void external (){
   delay_ms(50);
   if ( ! input(PIN_B0) ){
      printf("This is a message triggered by an external interrupt! ");
   }
}

void main (){
   lcd_init();
   setup_uart(9600);
   port_b_pullups(true);

   int ctprint;
   int ctcmd;
   int ctbyte;
   int posit = 1;
   int eeptmp;
   int eeadd;
   short cline = 0;

   printf(lcd_putc, "Hello World!\nPress button.");
   while( input(PIN_B0) );
   lcd_gotoxy(1,1);
   lcd_init();
   lcd_gotoxy(0,1);
   printf("Hello World! ");
   delay_ms(100);

   enable_interrupts(GLOBAL);
   enable_interrupts(INT_EXT);
   ext_int_edge (H_TO_L);

   while(true){
      ctprint=getc();
      if ( ctprint == 0x09 ){
         output_high(PIN_A0);
         ctcmd=getc();
            switch (ctcmd){
               case 0x42:
               case 0x62:
                  output_high(PIN_A1);
                  ctbyte=getc();
                  lcd_send_byte(0,ctbyte);
                  output_low(PIN_A1);
                  break;
               case 0x52:
               case 0x72:
                  lcd_init();
                  posit = 1;
                  cline = 0;
                  break;
               case 0x45:
               case 0x65:
                  output_high(PIN_A2);
                  eeadd=getc();
                  eeptmp=read_eeprom(eeadd);
                  printf("%c", eeptmp);
                  output_low(PIN_A2);
                  break;
               case 0x57:
               case 0x77:
                  output_high(PIN_A2);
                  output_high(PIN_A1);
                  eeadd=getc();
                  output_low(PIN_A0);
                  ctbyte=getc();
                  write_eeprom(eeadd,ctbyte);
                  delay_ms(8);
                  output_low(PIN_A1);
                  output_low(PIN_A2);
                  break;
               case 0x43:
               case 0x63:
                  output_low(PIN_A0);
                  output_high(PIN_A2);
                  int i;
                  for(i=0;i<128;i++){
                     write_eeprom(i,0xFF);
                  }
                  output_low(PIN_A2);
                  break;
               case 0x46:
               case 0x66:
                  output_low(PIN_A0);
                  output_high(PIN_A2);
                  for( i=0;i<127;i++ ){
                     eeptmp=read_eeprom(i);
                     printf("%c", eeptmp);
                  }
                  output_low(PIN_A2);
                  break;
               case 0x09:
               break;
            }
         output_low(PIN_A0);
      }
      else if ( !( posit == 16 && cline == 1 ) && posit != 17 && ctprint != 0x08 && ctprint != 0x0A ){
         lcd_putc(ctprint);
         posit++;
      }
      else if ( !( posit == 1 && cline == 0 ) && ctprint == 0x08 ){
         lcd_putc(0x08);
         lcd_putc(0x20);
         lcd_putc(0x08);
         posit--;
         if ( posit == 0 ){
            lcd_gotoxy(17,1);
            posit=17;
            cline=0;
         }
      }
      else if ( posit == 17 && cline == 0 && ctprint != 0x0A ){
         lcd_gotoxy(1,0);
         cline=1;
         lcd_putc(ctprint);
         posit=1;
      }
      else if ( ctprint == 0x0A && cline == 0 ){
         lcd_putc(ctprint);
         posit=1;
         cline=1;
      }
   }
}