Incredible!! Even this does not work. I am doing something incredibly
stupid, but I can't figure out what it is. Either that, or my programmer (a
Topmax) is totally bad, and saying that it is programming chips, and
verifying them, but not, and I can't believe that. Basically, I am now
using a 16F874 chip, because it is quick and easy to erase, and I cannot
get any code to work, although everything I try works fine in the
simulator. Also, I have noticed that in spite of putting in a line
TRISD=0x00, (or TRIS whatever), all ports appear to be tristated and
sitting at 0, since a 10k pullup resistor easily pulls them to high. The
only ports on my device that are at 1 are RD0 and RD1, because they are
pulled up by external pullups. (But, nothing I do can get them to 0.)

At this point, I am suspecting some strange hardware or programmer problem.
Does anyone have a simple (even as simple as the code attached below), that
is compiled for a 16F874. All I need is the hex file, and a brief
explanation of what it does, as long as the hex file is known to work on
actual hardware? Then, I could load that into one of my devices and see
what it does on the actual board.

TIA,
Ed
At 11:35 AM 8/6/2001 -0700, you wrote:
>>I have corrected the typo, although that would not have stopped something
>>from toggling. I checked my circuit, and it is basically the same as yours.
>>The only difference is that I hardwired ~MCLR to +5 volts. The rise time is
>
>
>etc.
>
>I can only offer a few more suggestions:
>
>1) Use an even simpler program for the test. e.g.
>
>main() {
>     TRISD = 0x00;
>     PORTD = 0x55;
>here:
>     goto here;
>}
>
>No matter what else is going on in the system, PORTD should get stuck
>at 0x55, and resets won't affect that.
>
>2) Are you sure you're building the application for the 1674B? It
>might be for another chip ...
>
>Regards,
>
>--
>
>  ______________________________________
>   Andrew E. Kalman, Ph.D.   aek@pumpkininc.com
>
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