>
> Nickolas Axelos wrote:
>
> > What should I do with the RB3 pin in order to successfully program the
> > PIC16F877 for the first time, when all I have is a high voltage
> > (12-14Volt) programmer (except from obtaining/building a LVP
> > programmer)?
> > I desperately need a solution for my final project in university.
> > Any advice or reference (or good news about the blown chip :) ) is
> > welcome.
> >
> > Thank you all in advance.
> >
> > Nickolas Axelos
>
> Use a 10K resistor from RB3 to +5V and a 100N cap from RB3 to GND.

Interesting. I was just re-reading the 16F87X programming specification and
I just don't see any reference to RB3 when high voltage programming the
part.

I ask because one of my students is at the point where she is trying to
program a 16F87X with a standard Tait style programmer. The programmer
does 16F84's just fine and we've modified the code to substitute a 0x18
begin programming only cycle instead of a 0x08 Begin programming erase
cycle which is simply a begin programming command for the 16F84.

The circuit you show above would pull RB3 from 0 to 5 volts. But is this
necessary if MCLR is going from 0 to 13V?

Look forward to your response.

BAJ