In message  <14595958302111@toastmaster.com> PICLIST@MITVMA.MIT.EDU writes:
> 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.
>
>

The osccal is there when you first get the PIC, but is erased
along with all the program code when exposed to UV.

The thing to do is read the value before you erase for the first time
and scratch it on the gold top or underneath.

Even with the osccal set properly, I would think you would get
different tones from your beepers as the internal oscillator is
only an RC type with sizeable variations in frequency part to
part due to manufacturing process variations etc.

Regards,

Mike Watson