Marco:

I've tried removing the 470 pF caps altogether, changing the pull up to a
2.2K with and without the caps. Still the same result.

I can take the data clock and connect it to the data input/output once the
software starts reading the data and the data input is all 0's so I know
the circuit is working somewhat.

I'm waiting for some new pics and am going to wait till then to try to
program anymore pics. Till then, if you or anyone else has any more
suggestions I'll like to try them out.

Thanks,

Shahid

----------
From:   Marco DI LEO[SMTP:m.dileo@SISTINF.IT]
Reply To:       pic microcontroller discussion list
Sent:   Monday, March 16, 1998 5:00 AM
To:     PICLIST@MITVMA.MIT.EDU
Subject:        Re: Problems with the ProPic programmer (newbie)

Shahid Sheikh wrote:
>
> Hi all,
>
> I just made a propic v4.2 (from TATO Computers) programmer and when I
read
> a blank (new) 12C509JW in it, it gives me 3FFF on all the locations. That
> is the same stuff I get if there is no pic on the programmer. The
> programmer seems to be working OK as it turns on and off all the supplies
> to the pic just fine. All my voltage levels are fairly accurate as well
> (VPP1=12.98V, VDDprog=4.97V, VDDmax=5.50V and VDDmin=2.54V).

I got the same problem on that programmer.
The problem I found is on the rising edges of the clock and data lines
used to program the PIC. Watching at them using a scope I saw a 45 deg
slope instead of sharp edge (perhaps may PC is too fast :-).
You should solve the problem REMOVING (or using a lower value) the 470pF
capacitor from RB7 and RB6 to ground or reducing the pull up resistors
to the same lines (R7 & R8).
I did the latter (I used 2.2K) and I am very happy with that programmer.

Try that and let me know.

   Marco


----
Marco DI LEO                  email: m.dileo@sistinf.it
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