static void timer0_isr (void) interrupt 1 using 1//highest priority
{
unsigned i;
TR0 = 0; 
i = TIMER0_COUNT + TL0 + (TH0<<8);
TL0 = i;
TH0 = i >> 8;
TR0 = 1;

address(1 << seg_count);
write(LCD_digits[seg_count]);
seg_count = (seg_count+1) & 0x07;

}