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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