On Tue, 4 Nov 1997 16:24:12 -0600 John Payson <supercat@MCS.NET> writes:
> If when I
>try to read back memory address zero the PIC outputs active data when
>and only when it should, then I assume the PIC is inserted correctly.
>If not, I shut off the power.  Even twelve volts, if current limitted
>to a couple of mA, isn't likely to hurt the PIC in the short time it's
>applied.

In order to attempt the read test, you need to apply high voltage to the
PIC, which could be trouble if applied to the wrong pin.

The PIC16X84 only senses the voltage applied to the MCLR line so it only
takes a few microamps, and the voltage is not too critical.  If much more
than 5V, the PIC goes to programming mode, otherwise normal operation.
The high voltage to force charge into the EEPROM cells is generated
internally (using the same voltage converter that supplies the data
EEPROM, I assume).

The EPROM PICs use the MCLR voltage to charge the ERPOM cells.  It has to
be capable of 10 mA as I remember, and also a too low voltage could cause
no or inadequate programming.  But they also warn that too "stiff" a MCLR
supply can latch the PIC up.