#include <reg52.h> // SFR declarations
#include <head.h> // SFR declarations

void UART_ISR (void) interrupt 4
{
     if(TI)
     {
        TI   = 0;
        SBUF	= 0XAA;//
     }
     else if(RI)
     {
	RI = 0;
     }
}
void Timer2_ISR (void) interrupt 5
{
     TF2    = 0;
     BUSY   = ~BUSY;
}