Well, I figured that the worst that could happen is that I would destory a $2.00 chip so I tried my test program with both MCLR on and MCLR off.

I found that with it off I didn't need the 4.7K resistor on pin 4 which I suspected. When it was turned on I did need the resistor so the setting does what it is supposed to do.

Even with this comment from the data sheet that the internal clock is turned off when MCLR=ON it seems to make no difference as in the program still runs. So, in actual use what are the differences? Do I leave off the resistor for my final project or not? What good or bad results do I get with either way?

Thanks.

Bart