PIC-nikkers: What happens to the OSCCAL number when you UV erase a windowed PIC12C508? Is the OSCCAL even programmed into windowed parts in the first place? I've noticed that piezo beepers hooked up to two different windowed parts usually have different tones, meaning the oscillators must run at different freq's. -- Lawrence Lile Download AutoCad blocks for electrical drafting at: http://members.sockets.net/~llile/index.htm