This is really bad but I have to ask as I am just feeling my way here.

I have cobbled together a bunch of stuff in an effort to learn 8051 use and simple programming. I have an 89c4051 processor, a 9.6 MHz crystal, 2 47 pF caps, a 5 V regulator a junky 9V power supply.

The programmer came today and I couldn't wait to actually do something.

Except nothing is happening. I am trying to assert a simple output pin. I've attached an led (w/ resistor) to this pin, 5V on one side, pin on the other. I wrote a simple program (BASCOM) turning the pin on, waiting a second, and turning it off.

I cycle power to the board and the led will either come on and stay on or come up off and stay off. There is no rhyme nor reason to what is going on. Supposedly the processor can sink enough current for this to work. I also tried an old RS logic probe which gave the same results.

How does one reliably measure the state of an output pin? Can someone send me a hex file pulsing a pin say every second so I can take the bascom compiler out of the loop?

Being new and not much with electronics certainly the problem here but I am at a loss. I guess the crystal is working ok. When I measure with the logic probe I can get it to buzz. Pulling the crystal out of the board causes the buzzing to stop. although as it nears the board there must be some inductance as the probe picks it backup even before inserted.

Anyway, this is really stupid but, well, I can't think of what else to do.

Thanks.