rynot

I have a 2 digit timer using common cathode 7segment displays. Because Im enlarging the displays to 3 inch I need to change them to common anode. and I want to add 2 more diplays to the circuit making it a 4 digit timer. I want to do this without changing the program on the pic. Any ideas on how to do this?

the pic is being used for other features that the unit has...ie buzzer control, mode functions and other functions.

I have a two digit countdown timer using a PIC16F872. The outputs are