Digital tube 60S counting display--C language

unsigned char code Tab[11]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0xff}; 
 // Segment code table of digital tube display 0~9

unsigned char int_time; //Record interrupt times
unsigned char second; //Store seconds
/************************************************************************
Function: Fast dynamic scanning delay, delay of about 0.6 milliseconds
********************************************************************/
void delay(void)
{
  unsigned char i;
  for(i=0;i<200;i++)
        ;
}
/***************************************************************************
Function: Display seconds
Input parameter: k
Output parameter: None
************************************************************************/
 void DisplaySecond(unsigned char k)
{
   
   P2=0xbf; //P2.6 pin outputs low level, DS6 lights up 
   P0=Tab[k/10]; //Display tens digit
   delay();
    delay();
       delay();
     delay();
      delay(); delay();
    delay();
       delay();
     delay();
   P2=0x7f; //P2.7 pin outputs low level, DS7 lights up 
   P0=Tab[k%10]; //Display the units digit
 delay();
     delay();
     delay();
      delay();
    delay(); delay();
    delay();
       delay();
     delay();
 P2=0xff; //Turn off all digital tubes

 P0=0xff; //Display units
   delay();
     delay();
      delay();
    delay(); delay ();
     delay();
    delay()
       ; delay();
     delay();
}     
  void main(void) //Main function
   {
   TMOD=0x01; //Use timer T0
   TH0=(65536-46083)/256; //Set the timer timing to 46083×1.085 microseconds
//=50000 microseconds=50 milliseconds
    TL0=(65536-46083)%256;
  EA=1; //Turn on total interrupt
  ET0=1; //Timer T0 interrupt enable
  TR0=1; //Start timer T0 and start running
  int_time=0; //Initialize the number of interrupts
  second=0; //Initialize seconds  
        while(1)
  {
        DisplaySecond(second); //Call the display subroutine of seconds
   }
    }  
//************************************************************
// Function: interrupt service routine of timer T0

//***********************************************************
  void interserve(void ) interrupt 1 using 1  
  {
    TR0=0; //Turn off timer T0
    int_time ++; //Every time an interrupt comes, the interruption count int_time is incremented by 1 
  if(int_time==20) //Enough interruptions, i.e. sampling the test result once every 1 second
   {
        int_time=0; //The interruption count is cleared to 0
     second++; //Increase the second by 1
     if(second==60)
       second =0; //If the second is equal to 60, it returns to 0
   }        
   TH0=(65536-46083)/256; //Re-initialize the counter T0
 TL0=(65536-46083)%256;
 TR0=1; //Start timer T0
 }