Probable the results would be rather catastrophic, There is a 200ľa li
mit
in current injected into any pin. If for ANY reason the protection diodes
are forward biased the chip will go into melt down. This comdition has been
known to burn labels off of 'JW' parts... One of the sure ways to destruct
a chip.

                Robert K. Johnson
                rkj1@ix.netcom.com

At 04:30 PM 7/5/99 +1000, you wrote:
>Hi....
>
>I'm interfacing a 16F84 to a 4051 analog mux with a 12V supply.
>Is it safe to put a 10k pullup resistor to +12V from the open drain output
>RA4?.
>
>
>Thanks
>Stewart.