#include<16f877a.h>
#use delay(clock=20000000)
#fuses NOLVP,NOWDT,NOPROTECT,HS


#byte porta=5
#byte portb=6
#byte portc=7
#byte portd=8

int count=0;


#int_EXT
void ext_isr()
{
 count++;
delay_ms(200);
}
void main()
{
 
set_tris_a(0x00);  
set_tris_b(0x01);
set_tris_c(0x80);
set_tris_d(0x00);

  output_d(0x00);
   output_c(0x00);
   enable_interrupts(GLOBAL);
   enable_interrupts(INT_EXT);
   ext_int_edge(L_TO_H);
while (1)
     {   
      switch(count)
        {
       case 1:
       output_d(0x77);//A
       delay_ms(100);
       output_c(0x01);
   
       break;
     
       case 2:
       output_d(0x7C);//B
       delay_ms(100);
       output_c(0x03);
   
       break;

       case 3:
       output_d(0x39);//C
       delay_ms(100);
       output_c(0x21);
  
       break;

       case 4:
       output_d(0x5E);//D
       delay_ms(100);
       output_c(0x31);
   
       break;

       case 5:
       output_d(0x79);//E
       delay_ms(100);
       output_c(0x11);
   
       break;
     
       case 6:
       output_d(0x71);//F
       delay_ms(100);
       output_c(0x23);
   
       break;

       case 7:
       output_d(0x6f);//G
       delay_ms(100);
       output_c(0x33);
    
       break;

       case 8:
       output_d(0x76);//H
       delay_ms(100);
       output_c(0x13);
    
       break;

       case 9:
       output_d(0x06);//I
       delay_ms(100);
       output_c(0x22);
    
       break;
     
       case 10:
       output_d(0x1E);//J
       delay_ms(100);
       output_c(0x32);
    
       break;

       case 11:
       output_d(0x76);//K
       delay_ms(100);
       output_c(0x05);
   
       break;

       case 12:
       output_d(0x38);//L
       delay_ms(100);
       output_c(0x07);
    
       break;

       case 13:
       output_d(0x15);//M
       delay_ms(100);
       output_c(0x52);
   
       break;
     
       case 14:
       output_d(0x54);//N
       delay_ms(100);
       output_c(0x53);
    
       break;
       
       case 15:
       output_d(0x3F);//O
       delay_ms(100);
       output_c(0x15);
    
       break;
     
       case 16:
       output_d(0x73);//P
       delay_ms(100);
       output_c(0x27);
    
       break;

       case 17:
       output_d(0x67);//Q
       delay_ms(100);
       output_c(0x37);
    
       break;

       case 18:
       output_d(0x50);//R
       delay_ms(100);
       output_c(0x17);
    
       break;

       case 19:
       output_d(0x6D);//S
       delay_ms(100);
       output_c(0x26);
    
       break;
     
       case 20:
       output_d(0x78);//T
       delay_ms(100);
       output_c(0x36);
    
       break;

       case 21:
       output_d(0x3E);//U
       delay_ms(100);
       output_d(0x0D);
    
       break;

       case 22:
       output_d(0x1C);//V
       delay_ms(100);
       output_c(0x0F);
    
       break;

       case 23:
       output_d(0x2A);//W
       delay_ms(100);
       output_c(0x3A);
    
       break;
     
       case 24:
       output_d(0x76);//X
       delay_ms(100);
       output_c(0x2d);
    
       break;

       case 25:
       output_d(0x6E);//Y
       delay_ms(100);
       output_c(0x3d);
    
       break;

       case 26:
       output_d(0x5B);//Z
       delay_ms(100);
       output_c(0x1d);
    
       break;
       
        case 27:
       output_d(0x54);//NUMBERS
       delay_ms(100);
       output_c(0x53);
    
       break;

         case 28:
       output_d(0x3f);//0
       delay_ms(100);
        output_c(0x32);
    
       break;

       case 29:
       output_d(0x06);//1
       delay_ms(100);
       output_c(0x01);
    
       break;

       case 30:
       output_d(0x5B);//2
       delay_ms(100);
       output_c(0x03);
    
       break;

       case 31:
       output_d(0x4F);//3
       delay_ms(100);
       output_c(0x21);
    
       break;
     
       case 32:
       output_d(0x66);//4
       delay_ms(100);
       output_c(0x31);
    
       break;

       case 33:
       output_d(0x6D);//5
       delay_ms(100);
       output_d(0x11);
    
       break;

       case 34:
       output_d(0x7D);//6
       delay_ms(100);
       output_c(0x23);
    
       break;

       case 35:
       output_d(0x07);//7
       delay_ms(100);
       output_c(0x33);
    
       break;
     
       case 36:
       output_d(0x7F);//8
       delay_ms(100);
       output_c(0x13);
    
       break;

       case 37:
       output_d(0x6F);//9
       delay_ms(100);
       output_c(0x22);
    
       break;

      
    }
   
      }
     }