Thanks for the reply Harold

I should have stated that I'm using 16F628A.  Would that make any difference?
You don't use a diode of any description then?  It looked to me that the diode
was allowing a pull-up for _MCLR, but stopping the +13v programming voltage
b*ggering up the rest of the cct.  Will a 10k do the same job?

The cct I was discussing was in the Microchip Mid-Range document, but was
lacking in actual numbers sadly.

Cheers,
Mark

> -----Original Message-----
> From: piclist-bounces@mit.edu 
> [mailto:piclist-bounces@mit.edu]On Behalf
> Of Harold Hallikainen
> Sent: 10 March 2005 16:33
> To: Microcontroller discussion list - Public.
> Subject: Re: [PIC]Microchip ICSP _MCLR circuit help
> 
> 
> It'd be GREAT if Microchip included this stuff in their datasheets. I
> pulled something from one of their eval boards and have used 
> it in several
> 18F based products. Here's what I use:
> 
> MCLR pin goes through 470 ohms and 220nF ceramic to ground.
> 
> MCLR has 10k pull-up to Vcc.
> 
> On a 2x5 header, pins are connected as follows:
> 
> 1 - MCLR
> 2 - Vcc
> 3 - ground
> 4 - PgD (RB7)
> 5 - PgC (RB6)
> 
> I have little adapter cables that have a ribbon cable spliced 
> to the RJ45
> (that's it, isn't it?) that plugs into the ICD-2.
> 
> Additional pins on the 2x5 header handle I/O required on the product.
> 
> This has been used on several 18F products and there are now 
> thousands in
> the field. Seems to work...
> 
> Harold
> 
> 
> 
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