> Be sure that the programmer has enough
> juice to pull the pullup resistor to low.

And more important, to pull it high to 13 Volt!

> 3) The clock is a major issue. If it's running when you try to program
it'll
> often screw your programming process up.

That is essentially the same problem: /MCLR must be pulled up to 13 Volt
*quickly* (expressed in the number of clock cycles, hence removing the
crystal or having a low frequency will help somewhat).

> 4) Lastly the programmer needs to be able to control Vdd. So the
programmer
> needs to be able to power the target.

Why?

Wouter van Ooijen
--
Van Ooijen Technische Informatica: http://www.voti.nl
Jal compiler, Wisp programmer, WLoader bootloader, PICs kopen

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