At 02:29 PM 24/02/97 +0100, you wrote:
>Hi Paulo,
>
>At 11:44 24/02/97 +0100, you wrote:
>>Hello,
>>
>>I'm working on a project that i use a PIC to decode magnetic card's. My
>>question is when i use an emulator on circuit board the PIC works OK,
>>but when i program a PIC and put the PIC on the board we dont't work.
>>Why, is my question. Please help me.
>>
>>Best Regards
>>Paulo Figueiredo
>
>I'm afraid nobody can answer your question if you are not a bit more
>precise. But let me share an experience I had, perhaps it gives you a clue.
>
>When I was working on a project with a 'C64 on a PC add-on card, I used the
>Parallel data bus feature of the 'C64 to communicate with the PC via the ISA
>bus. Everything worked very well with my emulator (Parallax ClearView).
>However, the customer complained that 'sometimes', a certain command from
>the PC to the PIC was ignored. After a long time of desperate search, I
>discovered that the interrupt flag of the parallel port was inadvertently
>cleared by any 'return' instruction! (two weeks after that, Microchip added
>the errata sheets to their web page, sigh..)
>
>The bound-out PIC used in my emulator had that bug fixed .....
>
>Perhaps you're encountering the same kind of problem. So check the errata
>sheet of the PIC you're using and check whether there are differences
>between the emulator PIC (a special version of the chip with more
>connections) and the 'real' one you're using
>
>Good luck, I know how you're feeling
>
>Jeroen
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>| Jeroen Ommering                        Cordless Systems Development |
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>

I have had similar problems and it is important to recognise the differences
between the two. In the case of the emulator I use(Advanced Transdata), it
does not look at either the external frequency ot the reset line. So I would
first check and ensure that the oscillator is woking and secondly that the
MCLR line is not being forced low at any time or has noise on it. I found
this to be the problem most of the time when I had this sort of problem.
Other problems may arise because of timing or some other exotic sources.

Best of luck,