In a message dated 97-07-01 14:52:40 EDT, you write:

<<
         The other day someone mentioned the automatic shutdown feature of
 most modern calculators. My question is can I do this on a PIC? I have a
 project that will be on for about 1 minute two or three times a week and I
 would like it to turn off during the down times. In a semi-dream state I
 imagined something with a relay and a mercury switch but when I actually
 tried to write it down it didn't really work. Any help is appreciated.

 Matt >>
Hi Matt,
I did this with a hand held laser device I designed.  Use a TOKO (or other
such as MAXIM) voltage regulator with a shutdown input.  Wire your ON button
to the regulator shutdown input from the battery (make sure the regulator
that you choose has an active high shutdown input (High = ON low = OFF).
 This turns the system on.  The PIC also has an I/O line connected to the
shutdown input of the V.R.  The first thing your code in the PIC does is
assign this bit to an output and set it true.  Now the PIC is in control of
its own power.  Do whatever you application does and then set this bit false
and all will shut off!

If you need more just holler
Dave Duley
V.P. DreiTek Inc.