> Van: cacciavite@bigfoot.com <leo.depalo@POMETIA.IT>
> Aan: PICLIST@MITVMA.MIT.EDU
> Onderwerp: Write voltage and MAX232
> Datum: zondag 8 november 1998 21:46
>
> Hi PICer,
>
> I have been an idea about the voltage level to program the PIC 17F84 and
I
> need to discuss with this list you about the faceability.

Ahem ....  I believe you mean the _16_ F84 ?

> The idea consist to use the charge pump of the +12 Volt of the MAX 232 to
> sink voltage and current to use for programming the 16F84 when only five
> volt are present.

My spec's of the MAX232 say that with a load of 3KOhm ( ! ) the voltage
drops to about 8 volts.  The maximum voltage (NO load present) is 10 volts.
 I'ts somewhat short of the 12.5 volts you need for EPROMS.  For a 16?84
(or other EPROM / FLASH controllers) it's O.K. , because the voltage is
only used as a "go into programming-state" signal.  It will draw _very_
little current.  My own experiences showed that 9 volts was enough to put
the 16C84 into the "programming-state".

Greetz,
  Rudy Wieser