Hi,

I believe to find problem... Just after NEXT1: label, you make a test on A but his value has changed during Display_Digit1 function calling....

But, about your code, ... ?? what do you want to do with Read_low and read_hi part ?? (your application seems to be a chronometer, is it ?)...

Between your latch and your 7-seg display, you have a BCD-7Seg converter ?