Hi Lucian, I have had a similar experience using a JDM programmer and the
16F628, sometimes it worked sometimes it didn't. I checked around for
answers and did variouse mods to the JDM programmer but to no avail.
In addition to the programming problem I found that my 16F628  chips were
failing for no apparant reason (other than programming them using the JDM
programmer?).
I think that one of the problems is the ability of the 16F628 to run a
program with no external clock and no reset i/p, this means that the 16F628
will sometimes try to run a program in the programmer with unpredictable
results.
  Better programmers have full control over all the pins required for
programming, a simple programmer like the JDM has limited control of these
signals.

I have used the same setup with many of the older PIC chips with no
problems. I think that the additional features of the 16F628 make it
unsuitable for use with this type of programmer so I am using my stock of
older PICs until I decide on a better programmer to buy.
--- John


> Hi all,
>
> I'm a beginner using Microchip PIC's and I have a problem with one
> design I'm working with.
> I have a JDM programmer and I use ICProg and PonyProg to program my
> chips (now using PIC16F628).
> The problem is that sometimes ICProg will give me error on the simplest

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