what on earth can I be doing wrong?

[dmacq]

thanks skimask for offering the simpler code.

I think you're probably right about the floating pin. Although, I connected a 1k resistor to it and gorund and the pin is still high. I don't have a scope to check though.
I have checked the config settings and tried every option but RC. But no luck. Tomorrow I'll rewire it for RC and see if that makes any difference.

And Duncan303, I think you're right too. The oscillator is almost certainly the problem. But as I say I've tried every configuration and nothing works. I have a smaller 16f876 pic that I will try in the morning.

So frustrating. But thank you so much for trying to help

[skimask]

thanks skimask for offering the simpler code.
I think you're probably right about the floating pin. Although, I connected a 1k resistor to it and gorund and the pin is still high. I don't have a scope to check though.
I have checked the config settings and tried every option but RC. But no luck. Tomorrow I'll rewire it for RC and see if that makes any difference.
And Duncan303, I think you're right too. The oscillator is almost certainly the problem. But as I say I've tried every configuration and nothing works. I have a smaller 16f876 pic that I will try in the morning.
So frustrating. But thank you so much for trying to help

Try a different spot in the breadboard, or a new breadboard.
We've had more than a few discussions here in the past year or so about breadboards gone bad (I should make a video...I'd make million$ !!!)... contacts wearing out, dirty contacts, etc.